typelevel/cats-effect

Executive summary

typelevel/cats-effect falls short of our standard for production because we found no logging, tracing or health checks in the code. It scores 61 out of 100 and is rated Adequate, and all 37 of its critical findings are security problems in the build pipeline and in its automatic dependency updates.

Production Readiness, at 57, is the weakest lens and counts most in the score. The best first step for the work it takes is recording design decisions, worth about 2 points. Adding a diagnostic log would lift Production Readiness itself, worth about 4 points. Raising Production Readiness to 70 would lift the score to about 64.

Thirty-five pipeline tools are referenced by a changeable name, so the build pipeline can be tampered with. One automatic update takes new releases before a bad one can be spotted. Pinning each tool to an exact version and setting a waiting period for automatic updates would close both risks. Correcting the flagged pipeline settings would fix the weakness in the build pipeline's configuration.

The product code is 39,178 lines, about €63,000 to rebuild.

Code Health 60 Adequate, capped by Nullable reference types Architecture 91 Adequate, capped by Project Cohesion Maturity 63 Adequate, capped by Architecture documentation Production Readiness 57 Adequate, capped by Observability Security and Compliance 78 Adequate, capped by Supply-chain Provenance & Signing Performance 72 Strong

A lens is capped at Adequate while one of its dimensions scores below 4 out of 10, however well the rest of the lens does. That way a serious problem in one place always shows in the lens's rating.

How the score is built: what each lens counts for The lenses don't count equally. The weakest lens counts most, the next weakest a little less, and so on, so a weak area pulls the score down instead of being averaged away. In the bar below, each part's width shows how much that lens counts and its colour shows its rating. Improving the widest part moves the score most, and as that lens improves, it counts for less, because another lens becomes the weakest.

Production Readiness 57 · counts for 46%Code Health 60 · counts for 25%Maturity 63 · counts for 14%Performance 72 · counts for 8%Security and Compliance 78 · counts for 4%Architecture 91 · counts for 2%

If Production Readiness rose from 57 to 70, the lowest score rated Strong, the score would rise from 61 to about 64.

Code composition: what the lines of code are

Product code 68%Tests 32%

New since the last survey: 2 findings

These 2 critical or serious findings weren't in the previous survey, on 12 October 2026.

Supply-chain Provenance & Signing · REDACTED
Supply-chain Provenance & Signing · REDACTED

Watchdog compares every finding with the previous survey's. A finding that has only moved to another line in the same file counts as the same finding, so only new findings appear here. Advisory notes from the AI model are left out, because the model words them afresh in every survey.

Fixed since the last survey: 2 findings

These 2 critical or serious findings were in the previous survey, on 12 October 2026, and are gone from this one.

Knowledge Freshness · Orphaned knowledge core/shared/src/main/scala/cats/effect/SyncIO.scala
Supply-chain Provenance & Signing REDACTED

Rebuild cost: about €63,000 · Estimate

Cost to rebuild	€21,000 to €110,000, for 349 to 1,108 hours of work, about 0.4 person-years for one engineer
Difficulty of the problem	Standard, judged from the kind of software and how it is built. Code that solves a harder problem, such as payments or medical bookings, costs more per line to write.
Quality factor	×0.8 at a score of 61. Better code takes more work to write, so the factor is ×1.0 at a score of 70, lower below it and higher above it.
Size	Medium: 39,178 lines of product code
What it is not	Not a quotation: nobody has offered to build it for that. Not a valuation: it says nothing about what the business is worth. Not a certified figure: no professional has signed it as one.

How the estimate is made: Watchdog prices the hours a team would need to write this code again, at €60 to €95 an hour. Declarations and boilerplate are priced at a fast rate and logic at a slower one, and the logic is then multiplied by the difficulty of the problem and by the quality factor. The estimate can be about 30% off either way, and it moves most with the hourly rate and the difficulty. For this code, every line is priced as straight logic, which keeps the estimate on the low side.

Top priorities

The three actions that raise the score most for the work they take. The full ranked list is in the Roadmap.

Resolve the 1 No ADRs found finding(s) in ADR Quality.

Raises the score by about 2 points · Low effort · ADR Quality

Write a diagnostic trail the user can hand back with a bug report: a log file under the platform's per-user data directory, switchable with a `--verbose`/`--debug` flag.

Start with the error paths that emit nothing — a discarded error is the failure the user cannot describe and you cannot reproduce.

Raises the score by about 4 points · Medium effort · Observability

On Scala 3, add `-Yexplicit-nulls` to `scalacOptions` so `String` and `String | Null` mean different things, and type each Java API's result as nullable where it can return null; on Scala 2 (or as a first step), enable WartRemover's `Null` wart (`wartremoverErrors += Wart.Null`) or Scalafix's `DisableSyntax.noNulls = true` so the code holds absence in `Option`.

Then pay the assertions down rather than adding to them: each `.nn` is a null the compiler could not rule out — wrap the Java value in `Option(…)` at the boundary, pattern-match on `null` once there, or change the API so the null cannot arrive; an `unsafeNulls` import switches the checking off for everything after it.

Raises the score by about 3 points · Medium effort · Nullable reference types

Diagnosis: what the measurements show together

Each conclusion below combines several dimensions into one point that no single dimension shows, and lists the measurements it rests on.

Where the investment is most exposed · Value at risk

This code would cost about €63,000 to build again, about 0.4 person-years of work. Its weakest lens is Production Readiness, at 57 (Adequate). Production Readiness is about whether the product is ready to run in production and to change without breaking. Because the weakest lens counts most in the score, work on Production Readiness also moves the score most.

Based on: the rebuild estimate · the Production Readiness grade · how much each lens counts

What to do: Start with the Production Readiness actions in Top priorities.

If you do one thing first · First action

Resolve the 1 No ADRs found finding(s) in ADR Quality. Of all the actions in this report, it raises the score most for the work it takes: about 2 points for low effort, because it clears the 1 ADR Quality findings. The next survey will show the change in the score.

Based on: the ranked actions in Top priorities, by score gain and effort

Architecture — module dependency graph

Project dependencies, layered top-to-bottom; arrows show direction. Any dashed red edge points upward or sideways, which only happens where the projects form a dependency cycle. A graph without cycles has none.

Architecture: which parts of the code depend on which

The code is divided into modules, groups of code that each handle one part of the product, and a module depends on another when it uses code from it. The table lists the modules both down the side and across the top, in an order where each module should only use modules listed above it. A number in a cell means the module on that row uses the module in that column, and it counts the pairs of building blocks (types) that connect them. The one thing to look for is a mark above the diagonal line. It means two or more modules use each other in a loop (a dependency cycle), so none of them can be changed, tested or released on its own.

120 modules, with 220 dependencies between them. 3 loops run through 31 of the modules, marked above the diagonal.

The table shows the 40 modules with the most connections; 80 more are left out to keep it readable.

Which modules use which. The module on each row uses the module in each column, and the number counts the pairs of types that connect them. A cell above the diagonal is part of a loop.
uses →	1 cats.effect.kernel.Par	2 cats.effect.kernel.Unique	3 cats.effect.std.Dispatcher	4 cats.effect.CallbackStack	5 cats.effect.kernel.Clock	6 cats.effect.kernel.MonadCancel	7 cats.effect.kernel.Ref	8 cats.effect.kernel.Resource	9 cats.effect.kernel.instances	10 cats.effect.kernel.syntax	11 cats.effect.std	12 cats.effect.unsafe.metrics	13 cats.effect.instances	14 cats.effect.kernel.Sync	15 cats.effect.std.syntax	16 cats.effect.unsafe.SelectorSystem	17 cats.effect.syntax	18 cats.effect.kernel	19 cats.effect.FiberInfo	20 cats.effect.kernel.GenSpawn	22 cats.effect.metrics	23 cats.effect.tracing	24 cats.effect.unsafe.KqueueSystem	25 cats.effect.IO	26 cats.effect.kernel.GenConcurrent	27 cats.effect.kernel.testkit	30 cats.effect.kernel.GenTemporal	33 cats.effect.unsafe	34 cats.effect
1 cats.effect.kernel.Par
2 cats.effect.kernel.Unique
3 cats.effect.std.Dispatcher
4 cats.effect.CallbackStack																													1
5 cats.effect.kernel.Clock																		8
6 cats.effect.kernel.MonadCancel																		23
7 cats.effect.kernel.Ref																		8	3
8 cats.effect.kernel.Resource																		8
9 cats.effect.kernel.instances	1												1					1
10 cats.effect.kernel.syntax			1														1	24
11 cats.effect.std																		15
12 cats.effect.unsafe.metrics																													1
13 cats.effect.instances									2
14 cats.effect.kernel.Sync					7	7												14
15 cats.effect.std.syntax											2						1	1
16 cats.effect.unsafe.SelectorSystem				1								1																	2
17 cats.effect.syntax										7	2				1			1
18 cats.effect.kernel	1	4	1				3	1					1	2			1		2
19 cats.effect.FiberInfo																		1											3
20 cats.effect.kernel.GenSpawn		5				5												15
21 cats.effect.laws														3				11
22 cats.effect.metrics												1						1											1
23 cats.effect.tracing																		1
24 cats.effect.unsafe.KqueueSystem												1						1										1	3
25 cats.effect.IO								1						2				8				7							30
26 cats.effect.kernel.GenConcurrent																		15		5
27 cats.effect.kernel.testkit	1							2						1				15	1
28 cats.effect.std.Queue											5							10	4
29 cats.effect.std.Supervisor		1									1							2	1
30 cats.effect.kernel.GenTemporal					5													10							5
31 cats.effect.kernel.Resource.ExitCase								3																1
32 cats.effect.kernel.testkit.TimeT																		3							1	2
33 cats.effect.unsafe				6								6				5			1				1	3					15
34 cats.effect			1	3							2	1	1	2			1	9	1		2	2		3				6
35 cats.effect.kernel.Async		5												5				20									5
36 (global)											1																		1
37 cats.effect.SyncIO														2				1						1					13
38 cats.effect.testkit											1							4								3		2	3
39 cats.effect.unsafe.EpollSystem												1						1										1	5
40 fix		1									1							8											5

Uses a module listed above itPart of a loopThe module itself

At a glance — Code Health · 60% · Adequate · gated by X5 ·

The Good

D3 · Scala God Classes 9.2 D4 · Scala Code Duplication 9.7 D17 · Scala Explicit Debt 9.8 GD1 · Repo Unfinished & placeholder code 10.0 IC1 · Repo Incompleteness & stubs 9.0 X1 · Repo Async correctness 10.0 X12 · Repo Unreachable branch 10.0 X13 · Repo Undrained process stream 10.0 X16 · Repo Unfloored truncation loop 10.0 X18 · Repo Disposal-pattern correctness 10.0 X19 · Repo Unrestored process-global state 10.0 X20 · Repo Mistyped argument guard 10.0 X21 · Repo Side-effecting pattern guard 10.0 X22 · Repo Contradicted release guard 10.0 X23 · Repo Unguarded diagnostic materialisation 10.0 X25 · Repo Inert configuration knob 10.0 X26 · Repo Unsynchronised callback handoff 10.0 X27 · Repo Collection changed while being enumerated 10.0 X28 · Repo Index access outside its own emptiness guard 10.0 X29 · Repo Per-element action decided by a fixed element 10.0 X30 · Repo Support guard that admits what it rejects 10.0

The Bad

D1 · Scala Cyclomatic Complexity 6.7 X3 · Repo Exception handling 5.4

The Ugly

D2 · Scala Cognitive Complexity 4.8 X5 · Repo Nullable reference types 2.0

At a glance — Architecture · 91% · Adequate · gated by D26 ·

The Good

D5 · Scala Coupling 10.0 D6 · Scala Cohesion (LCOM4) 9.2 D35 · Scala Change Coupling 10.0 AX10 · Repo Code composition 10.0 AX3 · Repo Project dependency cycles 10.0 AX4 · Repo Dependency direction 10.0 AX6 · Repo Interface segregation 9.9 AX8 · Repo Test isolation 10.0

The Ugly

D26 · Scala Project Cohesion 0.0

At a glance — Maturity · 63% · Adequate · gated by M2 ·

The Good

D15 · Scala Churn × Complexity Hotspots 9.7 D16 · Scala Bus Factor 9.2 D19 · Scala Documentation Quality 10.0 M1 · Repo Documentation (README) 8.7 M3 · Repo Folder & project structure 10.0 M4 · Repo Documentation accuracy 10.0

The Ugly

D20 · Scala ADR Quality 0.0 M2 · Repo Architecture documentation 0.0

At a glance — Readiness · 57% · Adequate · gated by P2 ·

The Good

D9 · Scala Test Distribution 10.0 D13 · Scala Secret Scanning 10.0 P1 · Repo CI/CD gates 10.0 P10 · Repo Library API & versioning 10.0 P3 · Repo Security & performance tooling 8.0

The Bad

P6 · Repo Release Hygiene 5.0

The Ugly

P2 · Repo Observability 0.0

At a glance — Security · 78% · Adequate · gated by D36 ·

The Good

D28 · Scala Secrets (history) 10.0 D30 · Scala Dependency Vulnerabilities 10.0 D43 · Scala Malicious Dependencies 10.0 X14 · Repo Bypassable address classification 10.0 X15 · Repo Unvalidated length from an untrusted reader 10.0 X17 · Repo Uncapped recursion over a caller-supplied document 10.0 X24 · Repo Document value interpolated into markup unescaped 10.0

The Bad

D29 · Scala Static Analysis (SAST) 6.4

The Ugly

D36 · Scala Supply-chain Provenance & Signing 2.5

At a glance — Performance · 72% · Strong ·

The Good

PF1 · Repo Benchmark discipline 9.0 PF3 · Repo Async & latency hygiene 7.0

The Bad

PF2 · Repo Allocation hygiene 6.3

Security & Compliance — OWASP Top-10 mapping

Findings mapped to OWASP categories; the specific CVEs/secrets are in the Security dimension cards below and findings.md (redacted only on the public version of this report).

OWASP category	Findings	Severity
A05:2025 — Injection	39	High / Critical
A03:2025 — Software Supply Chain Failures	6	Medium

Roadmap

First, implement user-facing diagnostic logging to capture error details for easier reproduction, and enforce strict null safety by enabling compiler checks and replacing unsafe null assertions with proper option handling. Next, establish a changelog to track release contents and resolve the missing architectural decision records. Finally, document significant design decisions in a dedicated folder to preserve context and consequences for future reference.

Ranked by impact ÷ effort. "Helps" is the estimated gain on the 0–100 health score.

Do this	Helps	Effort	Dimension
Resolve the 1 No ADRs found finding(s) in ADR Quality.	+2.5 pts	Low	ADR Quality
Write a diagnostic trail the user can hand back with a bug report: a log file under the platform's per-user data directory, switchable with a `--verbose`/`--debug` flag. Start with the error paths that emit nothing — a discarded error is the failure the user cannot describe and you cannot reproduce.	+3.9 pts	Medium	Observability
On Scala 3, add `-Yexplicit-nulls` to `scalacOptions` so `String` and `String \| Null` mean different things, and type each Java API's result as nullable where it can return null; on Scala 2 (or as a first step), enable WartRemover's `Null` wart (`wartremoverErrors += Wart.Null`) or Scalafix's `DisableSyntax.noNulls = true` so the code holds absence in `Option`. Then pay the assertions down rather than adding to them: each `.nn` is a null the compiler could not rule out — wrap the Java value in `Option(…)` at the boundary, pattern-match on `null` once there, or change the API so the null cannot arrive; an `unsafeNulls` import switches the checking off for everything after it.	+2.6 pts	Medium	Nullable reference types
Keep a changelog (e.g. Keep-a-Changelog) recording what shipped in each release.	+2.5 pts	Medium	Release Hygiene
Record your significant design decisions. Write one short document per decision, giving its date, the situation, the decision and its consequences, and keep them together with your other design documents. A docs/adr folder with each file named by number and title is the easiest place to find them.	+2.3 pts	Medium	Architecture documentation
Swallowed exception (caught, then discarded)	+1.6 pts	Medium	Exception handling
Bring the 2 bodies over 30 down to 30 or less in Cyclomatic Complexity — start with IOFiber.runLoop (cyclomatic 126), WorkerThread.run (cyclomatic 94).	+0.9 pts	Medium	Cyclomatic Complexity
Raise allocation-aware density on the hot paths — currently 28 use(s) across 43,096 production line(s) (~0.6/1k). More of the idioms below on the allocation-heavy paths climbs this toward 10.	+0.7 pts	Medium	Allocation hygiene

File quality

Per-file score 0–10 — a quality signature. Of 56 files carrying findings, judged against the Production bar: 2% slop · 59% mixed · 39% near-clean.

File	Score	Band	Worst signal
REDACTED	0.7	Slop	Static Analysis (SAST): High: REDACTED
core/shared/src/main/scala/cats/effect/IO.scala	5.6	Mixed	Cyclomatic Complexity: SyncStep.interpret (cyclomatic 22)
core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala	5.9	Mixed	Cognitive Complexity: Node.packHead (cognitive 22)
core/shared/src/main/scala/cats/effect/IOFiber.scala	6.0	Mixed	Explicit Debt: TodoComment
core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala	6.0	Mixed	Explicit Debt: TodoComment
core/native/src/main/scala/cats/effect/IOApp.scala	6.0	Mixed	Explicit Debt: TodoComment
std/shared/src/main/scala/cats/effect/std/Dispatcher.scala	6.0	Mixed	Explicit Debt: TodoComment
kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala	6.0	Mixed	Explicit Debt: HackComment
std/shared/src/main/scala/cats/effect/std/Queue.scala	6.0	Mixed	Explicit Debt: TodoComment
kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/Generators.scala	6.0	Mixed	Explicit Debt: TodoComment
core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala	6.0	Mixed	Explicit Debt: TodoComment
core/jvm-native/src/main/scala/cats/effect/unsafe/TimerHeap.scala	6.7	Mixed	Explicit Debt: TodoComment
core/jvm-native/src/main/scala/cats/effect/unsafe/WorkStealingThreadPool.scala	7.0	Mixed	Cognitive Complexity: WorkStealingThreadPool.shutdown (cognitive 28)
core/jvm/src/main/scala/cats/effect/IOApp.scala	7.1	Mixed	Cyclomatic Complexity: IOApp.main (cyclomatic 29)
std/shared/src/main/scala/cats/effect/std/Dequeue.scala	7.2	Mixed	Code Duplication: Duplicated block (11 lines × 2)
REDACTED	7.2	Mixed	Static Analysis (SAST): High: REDACTED
tests/jvm-native/src/test/scala/cats/effect/std/DeferredParallelismSuite.scala	7.3	Mixed	Explicit Debt: TodoComment
testkit/shared/src/main/scala/cats/effect/testkit/TestInstances.scala	7.3	Mixed	Explicit Debt: TodoComment
kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/TimeT.scala	7.3	Mixed	Explicit Debt: TodoComment
ioapp-tests/src/test/scala/IOAppSuite.scala	7.3	Mixed	Explicit Debt: TodoComment

How the grades work

Every finding carries one of four grades. Three say how serious it is. The fourth says this survey could not settle it — and it is a grade, not a gap.

Critical — 37

A definite problem that already costs you something and drags the score down: a missing authorisation check, a dependency with a known exploit, a build that does not reproduce. Failure here tends to cause failures elsewhere.

Serious — 151

Likely wrong, but not failing yet. It degrades the codebase over a longer horizon and can cause failures elsewhere — not urgent this week, not something to carry for two years either.

Minor — 23

Recorded, with no effect on how the codebase functions. Present so the survey is complete, not because it needs doing.

Could not be resolved — 12

Something this survey could not settle from the outside, and which could be critical or serious. Either a control was required and no positive evidence of it exists in the repository — a backup job that nothing shows was ever restored from proves nothing about restores — or our own analysis could not run over that part of the tree. This is not a clean result. These are excluded from the score rather than awarded a pass, so the number on the cover neither rewards nor penalises them: if you act on this survey without resolving them, you carry that risk yourself. Each one is named under Limitations.

Methodology & how to trust this report

Watchdog is a deep, periodic assessment — run each sprint, monthly, or quarterly, taking the time to go wider and deeper than a quick check and surfacing in one coherent report what you'd otherwise piece together from a dozen separate tools. It scores deterministically: the same commit yields the same score, every run. 61 of 61 evaluated dimensions are computed purely by tools and static analysis (confidence 1.0); none rely on LLM judgement. Overall confidence is 0.8 — the weighted average across measured dimensions; it falls as more of the score leans on LLM-assisted judgement and rises when it's fully tool-backed.

Every figure here is one of three kinds, and we label which: ✓ Measured — a deterministic fact (LoC, complexity, coverage); ~ Modeled — an estimate from a stated model (cost, effort, value-at-risk), always a range with its assumptions, never a precise fact; ◐ Advisory — an LLM prose judgement. We never present a modelled estimate as if it were measured. Perfect or absent scores carry their provenance too (ADR-0011): ✓ Tool-verified means the property itself was measured across the surface; ○ Nothing flagged means the probes came back clean — a claim bounded by what a repository can show; ⊘ Not evidenced means a working control (a tested restore, an automated rollback) showed no positive evidence — absence of evidence is not evidence of a control, so it's excluded from the score rather than awarded a spurious 10; ◐ Sampled · advisory marks an LLM verdict over a bounded sample — advisory, never a deterministic measurement.

What we checked — 61 dimensions across the health lenses

D1D2D3D4D5D6D9D13D15D16D17D19D20D26D28D29D30D35D36D43AX10AX3AX4AX6AX8GD1IC1M1M2M3M4P1P10P2P3P6PF1PF2PF3X1X12X13X14X15X16X17X18X19X20X21X22X23X24X25X26X27X28X29X3X30X5

Each chip is a dimension scored from real signals across architecture, testing, dependencies, security & compliance, documentation, git-history and code quality — in one coherent pass. A surface report typically covers a handful.

How to trust any code-health report — three questions

Can you open the finding? Real findings cite a repo-relative file and line you can open at the cited line — never an absolute scratch path. Here, 197 of 211 do; the remainder are repo-wide signals — a dimension-level measurement, not a single line. (Every path in this report is repo-relative by construction: paths are normalized at the producer and the report is rejected if any rooted path leaks through.)
Is there a tool behind the number? Every score below names the method that produced it — Roslyn, git, a scanner, or (for a handful of documentation/naming dimensions) an LLM labelled sampled · advisory — not a narrative.
Does re-running give the same result? Run it again on the same commit and the score — and this report, byte for byte — is identical. A report whose numbers move between runs is describing the run, not the code.

This report answers yes to all three. That's the bar to hold any assessment to.

Tools & methods

The actual versions used this run (captured at analysis time) — re-run on the same commit for the identical score.

Method	Backs	Version	Evaluator
Roslyn static analysis	Complexity, cohesion, coupling, dead code, API surface, layering	5.3.0	✓ deterministic
Native secret scanner	Hardcoded secrets / credentials	1.0.0	✓ deterministic
Watchdog duplication detector (in-process)	Code duplication	1.0.0	✓ deterministic
Coverage (coverlet / dotnet-coverage)	Line & branch coverage	10.0.400	✓ deterministic
NuGet / dotnet	Outdated, vulnerable & deprecated dependencies	10.0.400	✓ deterministic
git / LibGit2Sharp	Churn hotspots, knowledge concentration, history	2.43.0 · 0.31.0	✓ deterministic
gitleaks · semgrep · trivy	Secrets in history, SAST, CVEs, IaC & container, PII / GDPR	1.86.0 · 0.69.3	✓ deterministic
LLM (sampled · advisory)	Documentation quality, ADR conformance, naming — sampled over a bounded sample; advisory, never a deterministic measurement	—	◐ LLM · sampled · advisory

Every finding is locatable in findings.md. Run 01a176c1-9681-7f9d-bfa3-6fc64647c4af.

The exact command behind every deep-scan dimension — tool, version, invocation and retained raw output — is in Appendix B — Reproduction & audit trail.

Run transparency — what happened this run

What ran differently this time — a tool absent, degraded, or that fell back to an estimate. Named openly, not folded silently into the scores. A degraded run also records its exact cause in diagnostics.md.

D8 Code Coverage — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. Coverage NOT MEASURED: test source is present (.scala) but the built-in coverage collector has no runner for this repository's ecosystem — so this suite was never executed by it. Not scored — this is a gap in the analyzer's language coverage, not a defect in the repo. To have real coverage read, produce a coverage report in a standard format (`addSbtPlugin("org.scoverage" % "sbt-scoverage" % "<version>")` in `project/plugins.sbt`, then `sbt clean coverage test coverageReport`) and commit it — a hosted scan measures a clone of the repository, so a report that exists only in a working tree, a CI runner's or your own, never reaches it; the artefact is commonly gitignored, so `git add -f` that one file (or un-ignore its path) and commit it alongside the code it measures. You can widen what we reach: optional: produce a coverage report in a standard format (`addSbtPlugin("org.scoverage" % "sbt-scoverage" % "<version>")` in `project/plugins.sbt`, then `sbt clean coverage test coverageReport`) and commit it — a hosted scan measures a clone of the repository, so a report that exists only in a working tree, a CI runner's or your own, never reaches it; the artefact is commonly gitignored, so `git add -f` that one file (or un-ignore its path) and commit it alongside the code it measures — then the real number is read on the next scan.
D11 Test Reliability — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. Test source is present (.scala) and this repository declares an sbt build (repository root, 130 test files), but it was not re-run: no test result was produced. Not scored — this is a gap in the analyzer's language coverage, not a finding about this repository.
D12 Dependency Hygiene — not measured this run — This is a true statement about the repository that carries nothing for its owner to act on, so it is reported here rather than as a defect in their code. This repository's 1 package.json manifest(s) and its 1 committed lockfile(s) WERE read; what went unanswered is the currency half, because it grades the production `dependencies` a lockfile resolves and these manifests declare none — only 1 devDependencies, which D12 does not grade. So registry.npmjs.org was never asked, and there was nothing here for it to grade. This is a true statement about the repository and NOT a gap on our side: the lockfile was resolved, and no reader we could write would find a production dependency in it.
D14 License Compliance — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. Not scored — this repository's 5 sbt build file(s) (build.sbt and project/*.scala) were read and none of the production library dependencies they declare carries a version this pass can resolve from the file itself (2 declared with a version computed rather than written as a literal, or cross-built with `%%` where the build states no scalaVersion to form the Scala binary suffix from). sbt is a program rather than a manifest: a val holding one string literal is read, but anything computed would need the build run, and this pass does not run it. Licences are resolved from the POMs Maven Central publishes, which requires an exact coordinate to ask about. NOT a finding that this repository's licences are compliant: this dimension asserts nothing about its licensing in either direction.
D19 Documentation Quality — measured, with a gap in what it reached — Watchdog measured this, but not all of it. What it did not reach is a gap on our side — a collector, parser or image we have not built yet — so the numbers on that dimension cover less than the repository, and the part left out is not evidence that it would have passed. Each ecosystem's manifests (what makes a folder runnable or a published package) need their own proof before D19 judges its units. Until then those folders' READMEs are judged only as documents (boilerplate, structure), never counted as complete.
D21 Naming Consistency — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. D21's deterministic naming rules are gated on C# first (docs/plans/deterministic-engine.md, P5): each other language is switched on only after its own concept suite and A/B gate pass. Until then its declarations carry no naming verdict this run — this says nothing about whether its names are consistent.
D22 Internal API Consistency — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. D22 identifies the intentionally-exposed surface from `IsPackable` and `.Contracts` project names, MSBuild conventions read off the loaded project set. This target exposed no such projects, so the probe never ran; this says nothing about whether the repository has a public API. This repository commits no C#/VB source at all, so there was never an MSBuild project set to read these conventions off. That is OUR side and it is a COLLECTOR gap, not an environment fault: no published-package marker D22 reads admitted any project here, so this ecosystem's public API has no collector, and the remedy is to write one — no change to the scan image can close it.
D24 Comment Value — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. This check's reader does not cover the language this repository's product is written in, so it had nothing of the product to read. That is a gap in this analyzer's language reach — not a finding about this repository.
D27 Navigability — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. Navigability is taken over call sites whose callee resolved. For C# that population includes calls into referenced assemblies; for this language only calls declared inside the repository count, so the abstention threshold reads the repository's use of its standard library as a resolution failure. That is a limit of this analyzer, not a build problem in this repository.
D34 Knowledge Freshness — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. File-level freshness contradicts repo activity: 50 commits in the last 90 days, yet 100 of 135 significant files carry no living knowledge. Those two readings cannot both be true, so the per-file recency signal is treated as unreliable here and freshness is not scored for this run.
D44 Platform End-of-Life — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. This dimension reads a project's own statement about the platform it runs on: a TargetFramework in a .NET project file, a .nvmrc or .python-version, a capped requires-python, a Rust toolchain file or Cargo.toml rust-version, a .go-version, .java-version, .ruby-version, .tool-versions or .sdkmanrc, a go.mod go directive, a Maven or Gradle Java level or toolchain, a Gemfile's ruby directive, a mix.exs elixir requirement, a rebar.config minimum_otp_vsn, a pubspec.yaml SDK constraint, a build.sbt scalaVersion, or a framework major pinned by a dependency constraint. This repository carries none of them, so nothing about its platform was established. That is a gap in this analyzer's coverage, NOT a finding that the platform is supported — a language whose runtime is declared elsewhere (Package.swift, a Dockerfile) is simply not read here yet.
C1 Data Protection — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. These personal data controls are read from declarative annotations, request middleware, entity/column names and guard methods in a C# source model, and none was loaded on this run, so there was nothing to gather. That is a gap in this analyzer's language reach — not a finding that the repository lacks personal data controls.
C2 Access Controls — not measured this run — Watchdog could not measure this here. That is a gap on our side — a collector, parser or image we have not built yet — and it is neither a defect in this repository nor evidence that the check would have passed. These authorization controls are read from declarative annotations, request middleware, entity/column names and guard methods in a C# source model, and none was loaded on this run, so there was nothing to gather. That is a gap in this analyzer's language reach — not a finding that the repository lacks authorization controls.
M4 Documentation accuracy — measured, with a gap in what it reached — Watchdog measured this, but not all of it. What it did not reach is a gap on our side — a collector, parser or image we have not built yet — so the numbers on that dimension cover less than the repository, and the part left out is not evidence that it would have passed. M4 checks only the claim kinds adjudicated at or above 95 % precision: links and versions (PREREGISTRATION version 9). Paths, command arguments, installs, environment variables, settings, projects, packages, routes, cd targets, infrastructure products and removed modules are read but not checked, and none of them is reported or counted.
P5 DR & Backup — not measured this run — This is a true statement about the repository that carries nothing for its owner to act on, so it is reported here rather than as a defect in their code. No backup/snapshot/replication config, RTO/RPO or restore-procedure documentation was found — and no production persistence was detected either (no data-access packages, no data-store services, no database resources), so there is nothing in this repository whose loss a DR control would recover. If this system's data lives in a platform or ops repo we can't see, that's where the DR evidence belongs.

Repo exclusion declarations (.gitattributes linguist-generated/vendored, .editorconfig generated_code): none declared — every source file was scored.

Limitations & what we did not check

Watchdog assesses the repository exactly as committed, and only the repository. By design it does not reach outside the source tree: the live cloud account, the running CI/CD pipeline, the host's branch-protection and approval rules, the production configuration, or a restore actually exercised against a backup are all out of scope. That boundary is a feature, not a gap — a repo-relative, deterministic scan re-runs identically on any commit and every finding opens at a real file and line, where a live audit can neither be reproduced nor traced. The visible consequence is that controls which leave no in-repo evidence are reported as "not evidenced" and excluded from the score rather than awarded a number a static scan cannot justify.

Per-dimension blind spots

For each dimension that was measured, what a static, repo-only scan structurally cannot see — the honest edge of the measurement, not a failure of it.

D1 Cyclomatic Complexity: Cyclomatic complexity counts branches statically — it cannot tell an essential decision tree from accidental tangle, nor see complexity that lives in data or configuration (large switch-case token tables, DSL lexers/parsers, data-as-code rule tables) rather than control flow: a tokenizer's many single-character cases read as high complexity though each branch is trivial.
D2 Cognitive Complexity: Cognitive-complexity heuristics approximate how hard code is to follow; genuine domain difficulty and well-named intent that eases reading are not captured.
D3 God Classes: "God class" is sized by members and responsibilities visible in the type — a deliberately broad facade over a coherent subsystem can read the same as an accidental grab-bag. For front-end JS the file-length check is cohesion-aware (a single-responsibility module — one class/IIFE — earns a 3× threshold), but cohesion is approximated from top-level declarations, not true dependency structure.
D4 Code Duplication: Duplication is token-similarity — an in-process token-stream comparison over sliding windows, with type-aware normalization — so it finds copy-paste, not semantic duplication expressed differently. Committed machine-written code (scaffolded migrations, designer/codegen output, protobuf/OpenAPI stubs, model snapshots) is EXCLUDED — its repetition is the tool's, not the team's — so the score reflects hand-written duplication only.
D5 Coupling: Coupling is measured between projects/assemblies — runtime coupling through DI, reflection, messaging or shared databases is invisible to a static reference graph.
D6 Cohesion (LCOM4): LCOM4 cohesion is syntactic — it infers connectivity from which methods touch which fields/methods by name, not from real runtime behaviour or intent.
D9 Test Distribution: The test-pyramid shape is inferred from project/folder naming and references, with a single test host bucketed per-file by its path tier and content signals — a suite that names tiers unconventionally and gives no per-file signal can still be mis-bucketed.
D13 Secret Scanning: Secret detection is signature- and entropy-based on the current tree — a secret that does not match a known pattern, or one already rotated, will not be flagged (a clean scan is "nothing matched", not "no secrets exist").
D15 Churn × Complexity Hotspots: Churn hotspots come from git history — a freshly imported or squashed repository has no churn signal, and recent rewrites can mask a historically risky file.
D16 Bus Factor: Bus-factor is a time-decayed model of commit attribution (who has recently, repeatedly worked a file), not comprehension — pairing, review and reading-without-committing spread knowledge it can't see; bot commits and shared accounts still distort it.
D17 Explicit Debt: Acknowledged-debt signals (TODO/FIXME, suppressions, dead code) are textual — undocumented debt that nobody marked, and debt that lives in design rather than annotations, is invisible. Committed machine-written code (scaffolded migrations, designer/codegen output, generated stubs) is excluded — it is never the team's dead code to delete.
D19 Documentation Quality: Documentation quality publishes two things only: a runnable or packaged unit with no example, and a multi-project root README that maps none of its parts. It does not judge clarity, and its other checks (overview, licence, boilerplate, structure, empty sections, XML-doc coverage) are withheld after adjudication: their candidates are counted in the card's gaps, not shown as rows. A false statement in a document is M4's; units are .NET projects only.
D20 ADR Quality: ADR quality is an LLM read of the decision records present — it cannot know about decisions made and never recorded, and its verdict is sampled and advisory.
D26 Project Cohesion: Project focus is sized from members/namespaces per project — a project that is broad by deliberate design reads the same as one that has sprawled.
D28 Secrets (history): Secret-history scanning sweeps the git log for known patterns — a secret that predates the available history, or never matched a signature, is not found (clean means "nothing matched in the history we can see").
D29 Static Analysis (SAST): SAST findings are pattern-based (semgrep) — it finds classes of bug it has rules for; logic flaws, auth/authorization gaps and issues needing runtime context are out of reach (and clean means "no rule matched").
D30 Dependency Vulnerabilities: CVE matching depends on accurate package/version metadata and on the advisory databases — a vulnerability with no published advisory, or in code not declared as a dependency, is not seen. Coverage needs a RESOLVED graph: an unpinned requirements.txt, or a pom without a resolved build, yields partial coverage rather than a clean verdict. An ecosystem the analyzer cannot scan is reported as unmeasured, never as clean.
D35 Change Coupling: Change coupling is co-change in COMMITS — files split across separate commits, or coupled only through a shared config/build step, read as uncoupled, and a sweeping commit (rename/format) is excluded so it doesn't couple everything. It shows that files change together, not WHY: a high coupling can be a healthy cohesive pair as readily as a hidden leak.
D43 Malicious Dependencies: Only packages some vulnerability database has already NAMED as malicious are seen — a compromise published in the last hours, or never reported at all, is invisible here, and this dimension reading 10 is not evidence that a dependency is trustworthy. There is no typosquat or dependency-confusion analysis: a package nobody has reported is simply absent from the feeds. Coverage is the dependency scan's: an ecosystem that could not be scanned is disclosed as unmeasured, never as clean.
AX10 Code composition: Role is inferred from namespace/folder convention, not semantics — a domain concept living in a folder named "Services" reads as application, and the split is lines-of-code, not business value. The business-logic-share score is a SOFT, FLOORED signal: it contributes to the Architecture lens but is floored at the Critical gate, so an infrastructure-heavy design (a gateway, an ETL, a driver) is legitimately low without being nuked to zero.
M4 Documentation accuracy: Onboarding quality is an LLM read of the docs/setup present — it cannot run the onboarding or measure how long a real new joiner takes; the verdict is sampled and advisory.
P6 Release Hygiene: Rollback/observability controls are inferred from repo artefacts (pipelines, dashboards-as-code) — controls configured in external tooling, with no in-repo trace, cannot be credited.

Dimensions

D1 · Cyclomatic Complexity6.7 / 10Adequate✓ Tool-verified

What it measures: How tangled the control flow is — methods with many branches are hard to test and change.

Method: Cyclomatic complexity per method (1 + decision points), computed exhaustively across production source; test projects separated by convention. Deterministic.

Maturity: Documented → Verified → Prevented · effective 6.7 / 10 · rule-coverage 100% · ceiling Prevented

14 method(s) exceeded the cyclomatic complexity threshold of 15; the worst was IOFiber.runLoop at 126.

IOFiber.runLoop (cyclomatic 126)core/shared/src/main/scala/cats/effect/IOFiber.scala:210

WorkerThread.run (cyclomatic 94)core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:312

IOApp.main (cyclomatic 29)core/jvm/src/main/scala/cats/effect/IOApp.scala:406

SyncIO.unsafeRunSync (cyclomatic 29)core/shared/src/main/scala/cats/effect/SyncIO.scala:226

IOFiberPlatform.interruptibleImpl (cyclomatic 24)core/jvm-native/src/main/scala/cats/effect/IOFiberPlatform.scala:27

+ 9 more group(s) — more in Appendix A; the complete list is findings.md.

What to do

Bring the 2 bodies over 30 down to 30 or less in Cyclomatic Complexity — start with IOFiber.runLoop (cyclomatic 126), WorkerThread.run (cyclomatic 94). — This score is capped by its worst body, so a finding fixed alone moves it by almost nothing — the next one down takes its place. Refactoring these 2 together lifts Cyclomatic Complexity from 6.7 to about 8.2/10, projected with the scoring formula itself and assuming each lands exactly at 30; a cleaner split scores higher.
Enforce Cyclomatic Complexity in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d1_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D2 · Cognitive Complexity4.8 / 10Weak✓ Tool-verified

What it measures: How hard the code is for a person to follow, beyond raw branching.

Method: Cognitive complexity per method (Sonar-style nesting-penalized score), computed exhaustively over production code, excluding test projects. Deterministic.

Maturity: Documented → Verified → Prevented · effective 4.8 / 10 · rule-coverage 100% · ceiling Prevented

32 method(s) exceeded the cognitive complexity threshold of 15; the worst was IOFiber.runLoop at 316.

Node.packHead (cognitive 22) · ×2core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:185

IOFiber.runLoop (cognitive 316)core/shared/src/main/scala/cats/effect/IOFiber.scala:210

WorkerThread.run (cognitive 284)core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:312

IOFiberPlatform.interruptibleImpl (cognitive 112)core/jvm-native/src/main/scala/cats/effect/IOFiberPlatform.scala:27

Executor.sequential (cognitive 71)std/shared/src/main/scala/cats/effect/std/Dispatcher.scala:509

+ 26 more group(s) — more in Appendix A; the complete list is findings.md.

What to do

Bring the 2 bodies over 120 down to 120 or less in Cognitive Complexity — start with IOFiber.runLoop (cognitive 316), WorkerThread.run (cognitive 284). — This score is capped by its worst body, so a finding fixed alone moves it by almost nothing — the next one down takes its place. Refactoring these 2 together lifts Cognitive Complexity from 4.8 to about 5.8/10, projected with the scoring formula itself and assuming each lands exactly at 120; a cleaner split scores higher.
Enforce Cognitive Complexity in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d2_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D3 · God Classes9.2 / 10Stronggated by 12 serious findings✓ Tool-verified

What it measures: Over-large classes that try to do too much ("god classes").

Method: God-class detection by line and method-count thresholds per logical type (partial classes unified), filtered for generated code and registration/contract false positives. Deterministic.

Maturity: Documented → Verified → Prevented · effective 9.2 / 10 · rule-coverage 100% · ceiling Prevented

12 god class(es) detected.

TooManyMethods: IO · ×6core/shared/src/main/scala/cats/effect/IO.scala:117

FileTooLong: effect/IOFiber.scala · ×6core/shared/src/main/scala/cats/effect/IOFiber.scala

What to do

Resolve the 6 TooManyMethods finding(s) in God Classes — start with IO.scala (2), Resource.scala (2), IOFiber.scala. — One of this dimension's main actionable groups (6 warning-level).
Resolve the 6 FileTooLong finding(s) in God Classes — start with IOFiber.scala, IO.scala, Resource.scala. — One of this dimension's main actionable groups (6 warning-level).
Enforce God Classes in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d3_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D4 · Code Duplication9.7 / 10Stronggated by 29 serious findings✓ Tool-verified

What it measures: Copy-pasted code that should be shared instead.

Method: Code duplication via token-stream sliding windows with type-aware normalization (locals masked, type names preserved), density-scored per KLoC of production code. Deterministic.

Maturity: Documented → Verified → Prevented · effective 9.7 / 10 · rule-coverage 100% · ceiling Verified

28 duplicated block group(s) detected. One further row reports members as variants of one another; it aggregates block groups already counted above and is not itself counted.

Duplicated block (6 lines × 2) · ×4core/js/src/main/scala/cats/effect/ByteStack.scala:42

Duplicated block (9 lines × 2) · ×3core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:244

Duplicated block (20 lines × 2) · ×2core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:233

Duplicated block (19 lines × 2) · ×2core/shared/src/main/scala/cats/effect/IOFiber.scala:336

Duplicated block (14 lines × 2) · ×2core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:384

+ 14 more group(s) — more in Appendix A; the complete list is findings.md.

What to do

Resolve the 4 Duplicated block (6 lines × 2) finding(s) in Code Duplication — start with GenSpawnLaws.scala (2), ByteStack.scala, PQueue.scala. — One of this dimension's main actionable groups (4 warning-level).
Resolve the 3 Duplicated block (9 lines × 2) finding(s) in Code Duplication — start with Dequeue.scala (2), IORuntimeCompanionPlatform.scala. — One of this dimension's main actionable groups (3 warning-level).
Resolve the 2 Duplicated block (20 lines × 2) finding(s) in Code Duplication — start with CallbackStack.scala, IOApp.scala. — One of this dimension's main actionable groups (2 warning-level).
Enforce Code Duplication in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Verified — provenance only; does not change the score.

Detailed fixes: d4_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D5 · Coupling10.0 / 10Exemplary✓ Tool-verified

What it measures: Whether volatile projects sit underneath others that depend on them (so their churn ripples upward), and whether project dependencies form cycles. A widely-depended-on but stable shared/kernel project is healthy, not penalised.

Method: Dependency cycles via elementary-DFS over real .csproj references, plus Martin instability (afferent/efferent) per project. Exhaustive over the reference graph, deterministic.

Coverage: Exhaustive · type-level: afferent/efferent coupling + cycles computed over every production type — the population is all types, not a name convention.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Prevented

18 production modules (sbt), 0 dependency cycle(s), 0 unstable depended-on module(s). Read from the build's own module declarations; a dependsOn spread (deps: _*) and a project whose directory a helper computes are not visible there; 0 module(s) off the main sequence, with abstractness counted on 11 of the 18 (the rest declare no modelled class or interface, export only macros, declare types in source no model reads, or have no source directory of their own).

✓ On the Gold path — maintain.

Detailed fixes: d5_recommendation.md.

Do you agree with this assessment?

D6 · Cohesion (LCOM4)9.2 / 10Stronggated by 4 serious findings✓ Tool-verified

What it measures: Whether a class's methods are focused on a single responsibility.

Method: LCOM4 cohesion per production class with at least two methods: connected components of methods sharing state or calls, computed syntactically. Deterministic, not a proxy.

Coverage: Exhaustive · type-level: LCOM4 cohesion computed over every production class — the population is all types, not a name convention.

Maturity: Documented → Verified → Prevented · effective 9.2 / 10 · rule-coverage 100% · ceiling Verified

4 of 62 classes have LCOM4 above 3.

Low cohesion: IORuntimeBuilder (LCOM4 9) · ×4core/shared/src/main/scala/cats/effect/unsafe/IORuntimeBuilder.scala:26

What to do

Resolve the 4 Low cohesion finding(s) in Cohesion (LCOM4) — start with IORuntimeBuilder.scala, WorkStealingThreadPool.scala, WorkStealingBenchmark.scala. — One of this dimension's main actionable groups (4 warning-level).
Enforce Cohesion (LCOM4) in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Verified — provenance only; does not change the score.

Detailed fixes: d6_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D9 · Test Distribution10.0 / 10Exemplary✓ Tool-verified

What it measures: Whether the test suite has a healthy mix of unit / integration / end-to-end tests.

Method: Test projects classified (Unit/Integration/BDD/E2E) from compiled metadata; test methods counted exhaustively across projects with placement-agnostic disk fallback. Deterministic.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

76 test methods: 76 unit, 0 integration, 0 BDD, 0 e2e. The Scala suite contributes 76 test case(s) across 13 file(s) in a test source set declaring at least one — every `test("…")`, `it("…")`, `property("…")` and `"…" in {…}` registration and every JUnit `@Test`, which is how munit, ScalaTest, utest, ZIO Test and specs2 declare a case; a case registered under a computed name is not counted, so this is a floor. Its tier split is INFERRED from paths and file names, except sbt's src/it source set, which the build declares.

✓ On the Gold path — maintain.

Detailed fixes: d9_recommendation.md.

Do you agree with this assessment?

D13 · Secret Scanning10.0 / 10Exemplary○ Nothing flagged

What it measures: Whether any secrets (keys, tokens, passwords) have leaked into the code.

Method: In-process native secret scanner (entropy plus signature patterns) across all tracked files; no external tool. A clean result is a measured 10, not no-data zero. Deterministic.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Prevented

Secret scan ran and found no leaked secrets.

✓ On the Gold path — maintain.

Detailed fixes: d13_recommendation.md.

Do you agree with this assessment?

D15 · Churn × Complexity Hotspots9.7 / 10Stronggated by 1 serious finding✓ Tool-verified

What it measures: Files that change often and are also complex — the riskiest hotspots.

Method: Per production file churn times cyclomatic complexity over a rolling window, computed from git and Roslyn/JS/Razor analysis. Exhaustive, deterministic per commit date.

Maturity: Documented → Verified → Prevented · effective 9.7 / 10 · rule-coverage 100% · ceiling Documented

Top hotspots: kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala (8×16=128)

Hotspot: kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scalakernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala:145

What to do

Resolve the 1 Hotspot finding(s) in Churn × Complexity Hotspots — start with GenConcurrent.scala. — One of this dimension's main actionable groups (1 warning-level).

Detailed fixes: d15_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D16 · Bus Factor9.2 / 10Exemplary✓ Tool-verified

What it measures: Whether knowledge is concentrated in too few people (the "bus factor").

Method: Living knowledge per author via time-decayed commit attribution (6-month half-life, focus weighting) across largest source files. Deterministic, avoids blame's mechanical-refactor false positives.

Maturity: Documented → Verified → Prevented · effective 9.2 / 10 · rule-coverage 100% · ceiling Documented

11 source file(s) have their living knowledge concentrated in one author (≥90% of recent, decayed contribution). The largest is core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala. Counted over 131 of the 322 production source files in this repository: 187 are under the ~2,400-byte size floor this dimension measures over, and the remaining 4 have no attributable history left to measure.

Off-boarding risk: anonymized user #1

Further sole-owners (lower concentration)

✓ On the Gold path — maintain.

Detailed fixes: d16_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D17 · Explicit Debt9.8 / 10Stronggated by 35 serious findings✓ Tool-verified

What it measures: Acknowledged debt left in the code — TODOs, dead code, suppressed warnings.

Method: Roslyn syntactic debt markers (suppressions/TODO/FIXME/HACK/empty-catch/commented-code/Obsolete) plus SymbolFinder dead-code analysis; weighted-debt-per-KLoC density deducted 2.0x per unit. Deterministic, exhaustive.

Maturity: Documented → Verified → Prevented · effective 9.8 / 10 · rule-coverage 100% · ceiling Prevented

35 deducted task-comment markers across 39178 LoC (0.1/KLoC) → score 9.8. Task comments only: this repository's language is read without a compiler, so D17's suppression, dead-code and commented-out-code arms did not run and this score counts fewer marker kinds than a .NET repository's would.

TodoComment · ×34tests/shared/src/test/scala/cats/effect/tracing/TraceSuite.scala:25

HackCommentkernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala:64

What to do

Resolve the 34 TodoComment finding(s) in Explicit Debt — start with WorkerThread.scala (4), EpollSystem.scala (3), IORuntimeConfigCompanionPlatform.scala (3). — One of this dimension's main actionable groups (34 warning-level).
Resolve the 1 HackComment finding(s) in Explicit Debt — start with GenConcurrent.scala. — One of this dimension's main actionable groups (1 warning-level).
Enforce Explicit Debt in CI to reach Verified (currently Documented). — Hardens enforcement from Documented toward Prevented — provenance only; does not change the score.

Detailed fixes: d17_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D19 · Documentation Quality10.0 / 10Exemplary○ Nothing flagged

What it measures: Whether the project's documentation is clear, complete, and useful.

Method: Every README, docs/ document and root guide parsed by its markup and measured in Unicode letters. Published: a runnable or packaged .NET project whose README (or a document it links, or a root guide) shows no example, and a root README naming none of three or more projects. Overview, licence, boilerplate, wall-of-text, empty-section and XML-doc rows are measured and withheld (counted in gaps) after adjudication. Deterministic, exhaustive, advisory.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

1 of 1 documentation facets pass in full. 51 document(s) read across 1 unit(s).

✓ On the Gold path — maintain.

Detailed fixes: d19_recommendation.md.

Do you agree with this assessment?

D20 · ADR Quality0.0 / 10Critical✓ Tool-verified

What it measures: Whether architecture decisions are recorded well (context, decision, consequences).

Method: Per-ADR judgment by language model at low temperature with two-pass stability; confidence is share of ADRs evaluated; enforcement-field presence detected deterministically. Advisory.

Maturity: Documented → Verified → Prevented · effective 0.0 / 10 · rule-coverage 100% · ceiling Documented

No architecture decision records were found.

No ADRs found

What to do

Resolve the 1 No ADRs found finding(s) in ADR Quality. — One of this dimension's main actionable groups (1 recommendation-level).

Detailed fixes: d20_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D26 · Project Cohesion0.0 / 10Critical✓ Tool-verified

What it measures: Whether each project is a focused, coherent unit rather than an oversized grab-bag.

Method: Project size overshoot penalties (LoC / public-type count / namespace count, 2-of-3 flag) weighted by log magnitude. Exhaustive across projects, deterministic, LLM-independent.

Maturity: Documented → Verified → Prevented · effective 0.0 / 10 · rule-coverage 100% · ceiling Documented

1 of 2 build units (npm, sbt) flagged as possibly oversized/incoherent.

Projects may be oversized for their cohesion

What to do

Resolve the 1 Projects may be oversized for their cohesion finding(s) in Project Cohesion. — One of this dimension's main actionable groups (1 recommendation-level).

Detailed fixes: d26_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D28 · Secrets (history)10.0 / 10Exemplary○ Nothing flagged

What it measures: Whether any secrets were ever committed — scanned across the full git history, not just now.

Method: Secret scan via TWO gitleaks detect passes in an isolated checkout — the full git history, then a second --no-git pass over the working tree as it stands — merged and de-duplicated by (rule, file, line); each match flagged High. Both invocations are recorded in the audit trail. Exhaustive; when the tool is absent, or when its output cannot be parsed into the expected shape, the dimension is WITHHELD as an explicit measurement gap on our side — unscored and excluded from the lens, never a hedged middling score.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

gitleaks scanned the full history AND the current working tree and found no secrets.

✓ On the Gold path — maintain.

Detailed fixes: d28_recommendation.md.

Do you agree with this assessment?

D29 · Static Analysis (SAST)6.4 / 10Adequate✓ Tool-verified

What it measures: Real static-analysis (SAST) findings — likely security bugs in the code, any language.

Method: Polyglot static analysis via semgrep across the repo using the pinned, image-baked p/security-audit + p/owasp-top-ten rulesets (no scan-time registry fetch); severity rules (ERROR/WARNING/INFO) map to a full-band severity-weighted score. Exhaustive, deterministic; degrades on parse failure.

Coverage: semgrep pattern rules over all files — exhaustive for the rule set, blind to classes of bug without a rule (clean = no rule matched).

Maturity: Documented → Verified → Prevented · effective 6.4 / 10 · rule-coverage 100% · ceiling Documented

39 finding(s): 0 critical, 37 high, 2 medium, 0 low. 35 unpinned-GitHub-Actions row(s) are reported here but scored by D36 (supply-chain provenance), which measures that posture as `pinned_actions` — one pinning decision is charged once, not once per lens. semgrep hit a parse error in 1 file(s) — `example/test-jvm.sh` (line 14) — so no absence of findings in the named regions is evidence of anything; rows reported elsewhere in those files are real. Fix the syntax error (or exclude the file deliberately) and re-scan to cover them. Separately, one or more rules could not re-parse an embedded snippet in 1 file(s) (e.g. a workflow `run:` block read as shell). Those files WERE scanned and their other rows are unaffected; only those rules' view of those snippets is missing.

REDACTED

What to do

Resolve the 1 REDACTED finding(s) in Static Analysis (SAST) — start with REDACTED. — One of this dimension's main actionable groups (1 issue-level).
Resolve the 1 REDACTED finding(s) in Static Analysis (SAST) — start with REDACTED. — One of this dimension's main actionable groups (1 issue-level).
No action in Static Analysis (SAST) — all 35 REDACTED finding(s) are reported here at file:line but scored by D36 (supply-chain provenance), so none is charged to this dimension. — One of this dimension's main actionable groups (35 issue-level, 0 of them charged here).

Detailed fixes: d29_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D30 · Dependency Vulnerabilities10.0 / 10Exemplary○ Nothing flagged

What it measures: Whether any dependency has a known published vulnerability (CVE), direct or transitive, in ANY ecosystem the repository declares — Dart pub, Elixir and Erlang via Hex, Go modules, Java and Kotlin via Maven/Gradle, JavaScript/npm, .NET/NuGet, PHP/Composer, Python/PyPI, RubyGems, Rust/Cargo and Swift.

Method: Dependency-CVE scan across every ecosystem the repository declares, scored ONCE. Three sources are unioned and deduplicated by advisory identity (rule id + alias closure, CVE<->GHSA) scoped to package+version, keeping the worst severity: `osv-scanner --recursive` over osv.dev for Dart pub, Elixir/Hex (and Erlang, whose `rebar.lock` syft first converts to a CycloneDX SBOM the scanner reads, with rows attributed back to the lock), Go, Java and Kotlin via Maven/Gradle (and Scala, whose sbt build's pinned direct declarations are written into a CycloneDX SBOM the scanner reads, with rows attributed back to the build file), npm, PHP/Composer, Python/PyPI, RubyGems, Rust/Cargo and Swift; `trivy fs --scanners vuln` for npm lockfiles; and `dotnet list package --vulnerable --include-transitive` for NuGet (with per-advisory collapse of the project x target-framework fan-out), plus a DECLARED-dependency arm that resolves a published gem's gemspec against rubygems.org where no Gemfile.lock is committed. `SeverityScore(c,h,m,l, normalizer 8.0)`. NotApplicable only when NO ecosystem is readable; if any applicable ecosystem could not be scanned the findings are REPORTED and the score is withheld. Supersedes the npm and OSV arms, retired 2026-09-05.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

No known-vulnerable dependencies in any ecosystem this repository declares.

✓ On the Gold path — maintain.

Detailed fixes: d30_recommendation.md.

Do you agree with this assessment?

D35 · Change Coupling10.0 / 10Stronggated by 1 serious finding✓ Tool-verified

What it measures: Whether files that change together actually belong together — pairs that repeatedly co-change in git history despite having no explicit code dependency, surfacing the hidden/logical coupling (and boundaries in the wrong place) a static scan can't see.

Method: Pairwise co-occurrence over the per-commit file sets in git history (production source only — tests and generated dropped): Degree-of-Coupling = shared ÷ min individual revisions, reported above noise floors (each file ≥10 revisions, ≥5 shared commits, ≥50% strength); sweeping commits excluded. Deterministic over fixed history.

Coverage: Population: PRODUCTION source files only — test and generated files are dropped before pairing, so a class co-changing with its own test (trivially ~100%) can't drown the real production↔production coupling. Pairs ranked by Degree-of-Coupling. A non-source file is never a coupling PARTICIPANT either: documentation, schemas, config and data files are dropped with the rest, so a code↔docs pair — a command and the reference page that restates it — is not reported however strongly the two co-change; nor is coupling that runs THROUGH a build step or config file.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

Strongest change-coupling: IO.scala↔GenConcurrentSyntax.scala 55%

Change coupling: IO.scala ↔ GenConcurrentSyntax.scalacore/shared/src/main/scala/cats/effect/IO.scala:1

What to do

Resolve the 1 Change coupling finding(s) in Change Coupling — start with IO.scala. — One of this dimension's main actionable groups (1 warning-level).

Detailed fixes: d35_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D36 · Supply-chain Provenance & Signing2.5 / 10Weak✓ Tool-verified

What it measures: Whether the build pipeline provides supply-chain integrity — generated provenance/attestation, signed artifacts (cosign/sigstore), an SBOM, and pinned build actions. Presence of the configuration, not a runtime guarantee.

Method: Supply-chain provenance/signing read deterministically from CI/build config (.github/workflows, .gitlab-ci.yml, azure-pipelines, Jenkinsfile, .circleci) + the release surface: four signals — generated provenance/attestation (SLSA/in-toto/actions-attest), artifact signing (cosign/sigstore/gitsign), an SBOM (syft/sbom-action/*.spdx.json/*.cdx.json), and SHA-pinned build actions — scored 10·present/denom. NotApplicable without a build pipeline. Detects configuration presence, not runtime enforcement.

Maturity: Documented → Verified → Prevented · effective 2.5 / 10 · rule-coverage 100% · ceiling Documented

1/4 supply-chain integrity signals present (provenance, signing, SBOM, pinned actions).

REDACTED

What to do

Resolve the 2 REDACTED finding(s) in Supply-chain Provenance & Signing — start with REDACTED, REDACTED. — One of this dimension's main actionable groups (2 warning-level).
Resolve the 1 REDACTED finding(s) in Supply-chain Provenance & Signing. — One of this dimension's main actionable groups (1 warning-level).
Resolve the 1 REDACTED finding(s) in Supply-chain Provenance & Signing. — One of this dimension's main actionable groups (1 warning-level).

Detailed fixes: d36_recommendation.md · top locations in Appendix A, every location in findings.md.

Do you agree with this assessment?

D43 · Malicious Dependencies10.0 / 10Exemplary✓ Tool-verified

What it measures: Whether any dependency the repository declares is published as MALICIOUS rather than merely vulnerable — a package that is an attacker's work, in any ecosystem osv-scanner reads. Scored apart from D30 because the answer is binary: there is no safe version to upgrade to, and the fix is to remove the package and rotate every credential it could have read.

Method: The same dependency scan D30 reads, partitioned on the scanner's own classification rather than rescanned: a row is MALICIOUS when its id is in the `MAL-` space (the ossf/malicious-packages feed) OR its `database_specific.cwe_ids` carries `CWE-506` ("Embedded Malicious Code"). Both channels are structural; the summary text is deliberately NOT read, because a malicious-package record whose summary says only "Critical severity vulnerability" is a real shape ([GHSA redacted]) and a text matcher misses it. Scored BINARY: any surviving row is 0, whatever its severity and however many CVEs sit beside it — a hostile dependency is not a quantity. Applicability and degradation are D30's: NotApplicable only when no ecosystem is readable, and an unscannable ecosystem degrades rather than reading clean. SCORED, not informational.

Maturity: Documented → Verified → Prevented · effective 10.0 / 10 · rule-coverage 100% · ceiling Documented

No dependency in any ecosystem this repository declares is published as malicious.

✓ On the Gold path — maintain.

Detailed fixes: d43_recommendation.md.

Do you agree with this assessment?

Frontend & cross-cutting dimensions

R = React/JS · M = Maturity · P = Readiness.

AX10 · Code composition10.0 / 10Exemplary✓ Tool-verified

Other · Architecture — How the codebase splits by code ROLE — domain, application, infrastructure, test, generated. The significance map behind the knowledge/coupling weighting, and a DDD signal in its own right: a thin domain core under fat infrastructure is the anemic-domain smell, quantified. How each file's role is decided, because the split is only as good as that: a generated name or a build-output tree makes it Generated, a test project makes it Test, and otherwise the file's NAMESPACE and PATH words are matched against fixed vocabularies in a fixed ORDER — domain, then infrastructure, then application — so a file whose words hit two layers is counted under the earlier one. A production file matching none of them counts as application, so that share reads 'application or unclassified' rather than a measured application layer. Roles come from naming convention, never from what the code does. On this repository the split was taken from the source tree on disk rather than from a loaded .NET workspace, so a file's role is decided by its PATH segments alone — no declared namespace was available to add to the evidence — and generated output is excluded from the census entirely rather than counted as a generated share.

Method: Roslyn line-count by code ROLE: every source file classified Domain/Application/Infrastructure/Test/Generated by namespace + path convention (the shared CodeRoleClassifier), then significant lines summed per role. Deterministic; the advisory score is the business-logic (domain+application) share of production code.

Coverage: Population: ALL source files, each bucketed into ONE of five roles (Domain/Application/Infrastructure/Test/Generated) by namespace + path convention — a file whose layer isn't named in the convention falls to Application (the neutral default), and the split is line-count, not semantic depth or business value.

What to do

The domain core is a small share of production code, but most of the rest matched no layer vocabulary at all — so this is not yet an anemic-domain finding. The namespace/path convention could not place that code, which makes the composition above a statement about the naming, not about the design. Name the layers (or check that the repository's conventions differ from the ones this check knows) before reading a thin domain into it.

Do you agree with this assessment?

AX3 · Project dependency cycles10.0 / 10Exemplary✓ Tool-verified

Other · Architecture — Whether the project-reference graph is acyclic (cycles block independent build/deploy and signal eroding boundaries).

Method: Project reference cycles via elementary-DFS over real .csproj references, using the engine shared with D5/D7; cyclic versus acyclic. Exhaustive, deterministic.

Do you agree with this assessment?

AX4 · Dependency direction10.0 / 10Exemplary✓ Tool-verified

Other · Architecture — Whether dependencies point inward (Domain ← Application ← Infrastructure/Web) — the clean-architecture dependency rule, checked across the project graph.

Method: Layer violations by name-segment inference (Domain/Core to Application to Infrastructure/Web) over the project-reference graph. Exhaustive over all projects, deterministic.

Do you agree with this assessment?

AX6 · Interface segregation9.9 / 10Exemplary✓ Tool-verified

Other · Architecture — Whether interfaces stay focused rather than fat — the Interface-Segregation principle (SOLID 'I').

Method: Roslyn scan: public interface declared-member counts (accessors fold into their property/event); fat-interface threshold (over 15 declared members) flagged per type. Each finding also reports the distinct-OPERATION count — members counted by name, so an overload group counts once — which decides whether it states the caller-side ISP harm or the implementer-side burden of an overload set. TypeScript: exported interfaces that declare behaviour, counted over their REQUIRED operations (method signatures and function-typed properties with no `?`, once per signature) — data-shape interfaces and ambient .d.ts declarations are outside the population; JavaScript declares no interfaces and is not applicable. Deterministic, type-level.

`PollerMetrics` declares 25 abstract members: `operationsOutstandingCount`, `totalOperationsSubmittedCount`, `totalOperationsSucceededCount`, `totalOperationsErroredCount`, `totalOperationsCanceledCount`, `acceptOperationsOutstandingCount`, `totalAcceptOperationsSubmittedCount`, `totalAcceptOperationsSucceededCount`, `totalAcceptOperationsErroredCount`, `totalAcceptOperationsCanceledCount`, `connectOperationsOutstandingCount`, `totalConnectOperationsSubmittedCount`, `totalConnectOperationsSucceededCount`, `totalConnectOperationsErroredCount`, `totalConnectOperationsCanceledCount`, `readOperationsOutstandingCount`, `totalReadOperationsSubmittedCount`, `totalReadOperationsSucceededCount`, `totalReadOperationsErroredCount`, `totalReadOperationsCanceledCount`, `writeOperationsOutstandingCount`, `totalWriteOperationsSubmittedCount`, `totalWriteOperationsSucceededCount`, `totalWriteOperationsErroredCount`, `totalWriteOperationsCanceledCount`. Counted over its ABSTRACT members — a `def` with no body or a `val`/`var` with no initializer, once per signature; concrete members, private and protected members, and members of a companion `object` are not counted, because no implementer is forced to write them. A wide interface forces every implementer and caller to depend on methods they don't use (the Interface-Segregation 'I' in SOLID). Split it into focused role-interfaces. — core/jvm-native/src/main/scala/cats/effect/unsafe/metrics/PollerMetrics.scala:19
`Random[F]` declares 18 abstract members: `betweenDouble`, `betweenFloat`, `betweenInt`, `betweenLong`, `nextAlphaNumeric`, `nextBoolean`, `nextBytes`, `nextDouble`, `nextFloat`, `nextGaussian`, `nextInt`, `nextIntBounded`, `nextLong`, `nextLongBounded`, `nextPrintableChar`, `nextString`, `shuffleList`, `shuffleVector`. Counted over its ABSTRACT members — a `def` with no body or a `val`/`var` with no initializer, once per signature; concrete members, private and protected members, and members of a companion `object` are not counted, because no implementer is forced to write them. A wide interface forces every implementer and caller to depend on methods they don't use (the Interface-Segregation 'I' in SOLID). Split it into focused role-interfaces. — std/shared/src/main/scala/cats/effect/std/Random.scala:42

What to do

Split fat interfaces into focused role-interfaces so clients depend only on what they use.

Do you agree with this assessment?

AX8 · Test isolation10.0 / 10Exemplary✓ Tool-verified

Other · Architecture — Whether production projects stay free of references to test projects — tests may depend on production, never the reverse.

Method: Csproj graph: each production project checked for references to test projects (identified by test-framework presence, not name). Zero violations is clean. Deterministic.

Do you agree with this assessment?

GD1 · Unfinished & placeholder code10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Unreviewed-generation residue in this repository's Scala: methods whose whole body is still `???` or a "not implemented" throw where nothing overrides them, and placeholder text (lorem ipsum, changeme/replace_me…) left in strings of non-test, non-generated code. Scored as a quality signature, never as a claim about authorship.

Method: Roslyn syntax scan: NotImplementedException throws and placeholder string literals in non-test, non-generated shipped code. Deterministic, code-shape signature.

Do you agree with this assessment?

IC1 · Incompleteness & stubs9.0 / 10Strong✓ Tool-verified

Other · Code Health — Unfinished work detected by code SHAPE, not keywords, in this repository's Scala: methods whose body is `???` or only throws a "not implemented" error, methods that take inputs and return a constant or do nothing, dead `if (false)` branches, and skeleton classes most of whose methods are holes.

Method: Roslyn syntax scan: incompleteness by code shape (constant-returning methods, async-never-await, #if false branches, guards that return what the code already falls through to, tests an earlier guard already decided, comparisons against NaN, skeleton types), not keyword-gated. Deterministic, code-shape heuristic.

`isVirtualThread` looks like it should compute a result but its body just returns a constant — a placeholder return that was never filled in. — core/js-native/src/main/scala/cats/effect/IOFiberConstants.scala:52
A test is skipped/ignored — coverage that looks present but never runs. Re-enable it or delete it so the green run means something. (×6) — ioapp-tests/src/test/scala/IOAppSuite.scala:249, tests/jvm/src/test/scala/cats/effect/IOPlatformSuite.scala:104, tests/jvm/src/test/scala/cats/effect/unsafe/WorkerThreadNameSuite.scala:57, …
`notSupported`'s body only throws UnsupportedOperationException — sometimes a deliberate refusal, often an unfinished stub. Confirm it's intentional. — std/js/src/main/scala/cats/effect/std/SecureRandomCompanionPlatform.scala:108

What to do

Finish or delete the unfinished stubs (functions that throw "not implemented", or whose body is empty or a bare constant) — they are dead surface that looks live.
Clear the softer debt: re-enable or delete `ignore`d and `pending` tests, decide whether each empty method or UnsupportedOperationException is deliberate (and say so in a comment), and replace a bare `// scalastyle:off` or `@nowarn` with targeted, justified suppressions.

Do you agree with this assessment?

M1 · Documentation (README)8.7 / 10Strong✓ Tool-verified

Maturity · Maturity — Whether the repo and its projects have a README, and whether it's substantive and current.

Method: Filesystem scan: README presence, word count, and headings for depth; git history for staleness. Exhaustive across root and project dirs, deterministic.

What to do

Explain in the README how to run the tests. Add a section called Testing to the README in the repository's top folder, saying how to run the test suite.
Add an 'Architecture' / 'How it works' section to the root README — the high-level shape.

Do you agree with this assessment?

M2 · Architecture documentation0.0 / 10Critical✓ Tool-verified

Maturity · Maturity — Whether key decisions (ADRs) and the high-level shape (C4/diagrams) are written down.

Method: Filesystem scan: ADR folder/naming conventions or content, plus Mermaid/PlantUML/C4/architecture.md discovery. Exhaustive, deterministic.

No Architecture Decision Records found — no conventional ADR directory, no numbered `NNNN-title` documents in any markup this check reads, and nothing ADR-shaped by content. Design rationale recorded elsewhere (a design-notes tree, a mailing list, pull-request discussion) is not visible to this check and is not re-findable per decision, so a future maintainer cannot ask why one choice was made and get an answer.
No C4/Structurizr/PlantUML/Mermaid/Graphviz/D2 diagram, no drawn diagram named for the architecture, no file named `architecture` or `design` in any markup this check reads, and nothing in the README, docs or contributor guides that announces the shape — no `## Architecture` heading, no "architecture overview"/"high-level design" phrasing, no "the architecture is …" introduction, no guided code tour. A shape laid out in prose that never names itself as the architecture is not visible to this check, and neither is one kept outside the repository, so this row reports the absence of a re-findable shape document — not evidence that nobody wrote the shape down.

What to do

Record your significant design decisions. Write one short document per decision, giving its date, the situation, the decision and its consequences, and keep them together with your other design documents. A docs/adr folder with each file named by number and title is the easiest place to find them.
Add a C4 context/container diagram (Structurizr, PlantUML or Mermaid) or an architecture.md overview.

Do you agree with this assessment?

M3 · Folder & project structure10.0 / 10Exemplary✓ Tool-verified

Maturity · Maturity — Whether the repo is organised deliberately — src/test separation and consistent project naming.

Method: Filesystem scan: src/test folder separation and namespace-prefix consistency (majority RootNamespace agreement). Exhaustive across projects, deterministic.

Do you agree with this assessment?

M4 · Documentation accuracy10.0 / 10Exemplary○ Nothing flagged

Maturity · Maturity — Whether the README actually describes the code that exists (LLM-judged, advisory).

Method: Judged by language model at low temperature: README accuracy versus actual projects, within a disclosed tolerance. Advisory, not a measured number.

Do you agree with this assessment?

P1 · CI/CD gates10.0 / 10Exemplary○ Nothing flagged

Readiness · Readiness — Whether an automated pipeline builds and tests every change.

Method: Filesystem scan: CI workflow files (.github/workflows, .gitlab-ci.yml, etc.) for build and test stages. Exhaustive, deterministic.

Do you agree with this assessment?

P10 · Library API & versioning10.0 / 10Exemplary○ Nothing flagged

Readiness · Readiness — For a library: a deliberate (small) public API surface and explicit semantic versioning so consumers can depend on it safely.

Method: Roslyn scan: public API surface area and semantic-versioning markers (SemVer attributes, changelog entries) for libraries; off .NET, a library is the ecosystem's publication act (an npm package that is not private and names an entry point, a PyPI distribution with a build system, a Rust library crate, a Maven/Gradle module that publishes, a Go module with no package main, a gemspec, a Composer library, a SwiftPM library product, a pub.dev or Hex package), its surface is the share of types the language model records as public (Rust, Swift, Java, Kotlin, Go, Dart; not measured where the model records no type visibility or, as in TypeScript, only module-level export), and its version is read from the manifest, a semver CHANGELOG, release tooling or semver git tags. Exhaustive, deterministic.

Do you agree with this assessment?

P2 · Observability0.0 / 10Critical✓ Tool-verified

Readiness · Readiness — Whether the code is diagnosable in production — structured logging, tracing/metrics, health checks.

Method: Filesystem/Roslyn scan: structured-logging frameworks (Serilog, NLog), OpenTelemetry, and health-check endpoint patterns. Exhaustive, deterministic.

No logging or diagnostics emission found. This repository ships a binary its users launch rather than a service you operate, so there is no operator to page — but when a run fails on a user's machine, neither they nor you have anything to read.

What to do

Write a diagnostic trail the user can hand back with a bug report: a log file under the platform's per-user data directory, switchable with a `--verbose`/`--debug` flag. Start with the error paths that emit nothing — a discarded error is the failure the user cannot describe and you cannot reproduce.

Do you agree with this assessment?

P3 · Security & performance tooling8.0 / 10Strong✓ Tool-verified

Readiness · Readiness — Whether SAST, secret/dependency scanning and performance benchmarking are wired in (presence, not runtime).

Method: Filesystem scan: SAST configuration, dependency-update automation, secret scanning, and a benchmark harness or benchmark step — in this repository's own ecosystem. Exhaustive, deterministic.

What to do

Dependabot is configured but does not watch `github-actions`, `npm` — add those `package-ecosystem` entries to REDACTED so those dependencies get the same automatic update and advisory pressure as the ones it already covers.
Add gitleaks/trufflehog in CI to block PRs that introduce committed secrets.

Do you agree with this assessment?

P6 · Release Hygiene5.0 / 10Adequate✓ Tool-verified

Readiness · Readiness — Whether releases are traceable — a maintained changelog and explicit version stamping.

Method: Filesystem scan: changelog file presence and version tags in csproj or git tags. Exhaustive, deterministic.

No CHANGELOG/HISTORY/RELEASES file — what shipped when isn't easy to reconstruct for support or audit. (Versioning/tagging makes releases traceable, but a changelog records the what.)

What to do

Keep a changelog (e.g. Keep-a-Changelog) recording what shipped in each release.

Do you agree with this assessment?

PF1 · Benchmark discipline9.0 / 10Exemplary✓ Tool-verified

Readiness · Performance — Whether the code protects its performance with benchmarks — a benchmark suite, allocation/memory measurement, and (ideally) a CI gate. Presence is credited as a bonus, never a deduction.

Method: Repo + source scan: BenchmarkDotNet referenced (csproj/source), [Benchmark]/[MemoryDiagnoser] attribute counts, and a benchmark step in CI; off .NET, the same ladder over Go testing.B, Rust criterion/#[bench]/divan, JMH/kotlinx-benchmark, pytest-benchmark/asv/pyperf, tinybench/mitata/vitest bench/benchmark.js and Swift package-benchmark — scored as a bonus ladder (absence is neutral, never a deduction). Deterministic, presence detection.

A JMH/Jetpack Benchmark suite exists but nothing turns on its allocation measurement — allocations (the main way hot code pressures a garbage collector or allocator) aren't being measured. — benchmarks/src/main/scala/cats/effect/benchmarks/ArrayStackBenchmark.scala

What to do

Run JMH with the GC profiler (`-prof gc`, or addProfiler(GCProfiler.class)) so allocation rate regressions are visible, not just time.

Do you agree with this assessment?

PF2 · Allocation hygiene6.3 / 10Adequate✓ Tool-verified

Readiness · Performance — Whether the code is written to minimise allocations so it doesn't pressure its host's memory manager — buffer/slice views over copies, object pooling, stack or value-type allocation, and buffer writers. Reward-only: credited where present, never penalised where a simpler style is fine.

Method: Production-source scan: density (per 1k LoC) of allocation-aware APIs — in .NET Span/Memory, ArrayPool/ObjectPool, stackalloc, ValueTask, value-type structs, IBufferWriter, string.Create, SkipLocalsInit; off .NET, with comments and strings blanked, Go's sync.Pool, preallocated slices/maps, Grow, strconv.Append* and buf[:0] reuse; the JVM's NIO buffer views, MemorySegment, primitive collections, pools and literal presizes (plus Kotlin primitive arrays and value classes, Scala AnyVal and @specialized); Swift's reserveCapacity, ContiguousArray, withUnsafe* access and ~Copyable. Activated off .NET on the same floor (400 lines, and benchmarks or 8 uses); Rust and garbage-collected scripting languages are not applicable. Reward-only. Deterministic, syntax/text detection.

What to do

Raise allocation-aware density on the hot paths — currently 28 use(s) across 43,096 production line(s) (~0.6/1k). More of the idioms below on the allocation-heavy paths climbs this toward 10.
Java: on hot paths, work through buffer views (ByteBuffer/LongBuffer slices, MemorySegment) instead of copies, avoid boxing with primitive collections (fastutil, Eclipse Collections, HPPC, Trove), presize collections and StringBuilders, and pool expensive buffers (Netty's pooled allocator, commons-pool).
Scala: on hot paths, make small wrappers value classes (extends AnyVal), @specialized generic code over primitives, use primitive collections, and presize builders.

Do you agree with this assessment?

PF3 · Async & latency hygiene7.0 / 10Strong✓ Tool-verified

Readiness · Performance — Whether asynchronous code stays responsive — it avoids sync-over-async blocking (a .NET .Wait()/.GetAwaiter().GetResult(), a time.sleep or blocking HTTP call inside a Python coroutine, a *Sync call inside an async JavaScript function, block_on inside a Rust async fn, runBlocking inside a Kotlin suspend function, block() inside a Reactor publisher) that stalls a thread or event loop and risks deadlock, and, where the code is a reusable library on .NET, awaits with ConfigureAwait(false) so it never captures and stalls its caller's context.

Method: Production-source scan: sync-over-async blocking counted everywhere — .Wait()/.GetAwaiter().GetResult() in .NET; off .NET, read from the language model, a blocking call inside an async function (Python, TS/JS, Rust, Kotlin, Swift, Dart) or inside a Java method returning a Reactor Mono/Flux or a Scala method returning a Future or effect — and, for a .NET library with ≥5 awaits, the share of awaits using ConfigureAwait(false). Deterministic, syntax/text detection.

`unsafeRunSyncToFuture` is async and calls unsafeRunSync — a blocking call inside async code stalls the execution-context thread, and every future or fiber scheduled on it for as long as it runs. (×2) — core/js/src/main/scala/cats/effect/IOPlatform.scala:61, core/js/src/main/scala/cats/effect/syntax/DispatcherSyntax.scala:45

What to do

Scala: compose the Future or effect (map/flatMap, a for-comprehension) instead of Await.result or unsafeRunSync, and wrap unavoidable blocking calls in blocking { } (Future), IO.blocking or ZIO.attemptBlocking.

Do you agree with this assessment?

X1 · Async correctness10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether the code avoids sync-over-async (deadlock-prone blocking on tasks) and async void.

Method: Roslyn syntax scan: async methods scanned for .Wait()/.GetAwaiter().GetResult() and async-void outside event handlers. Deterministic, hard fact per invocation.

Do you agree with this assessment?

X12 · Unreachable branch10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether any branch is dead by construction — a switch arm whose label can never equal a case-normalised subject, or an `else if` whose predicate the arm above has already swallowed.

Method: Roslyn syntax + semantics: switch labels compared against the subject's own case normaliser, and if/else-if chains checked for a literal an earlier arm's containment test already swallows. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X13 · Undrained process stream10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a child process that has BOTH standard streams redirected drains both — reading one to the end while the other is never read deadlocks once the child fills the unread pipe.

Method: Roslyn syntax + semantics: ProcessStartInfo launches with both streams redirected, checked for a drain of each stream across the enclosing type. On a repository with no .NET source it reads JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not) with the same rule: a `spawn` imported from `child_process` whose stdout and stderr are both pipes (no options, no `stdio`, or `stdio` of `'pipe'`), bound to a local that never leaves its scope, where exactly one of the two streams is read, the other never, and the child’s `close`/`exit` (or the read stream’s end) is awaited; a shell redirect in the call’s arguments or a `kill` of the child suppresses it. The same rule reads Python’s `subprocess.Popen`, Dart’s `Process.start`, Ruby’s `Open3.popen3`, and Scala’s JDK process starts (`new ProcessBuilder(…).start()` with no `redirectErrorStream`/`redirectError`/`redirectOutput`/`inheritIO`, `Runtime.getRuntime.exec`) where one of `getInputStream`/`getErrorStream` is read and the other never while `waitFor()` is called or the read stream is read to its end. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X14 · Bypassable address classification10.0 / 10Exemplary○ Nothing flagged

Other · Security — Whether a hand-rolled public/private IP check can be walked past — a method that unwraps IPv4-mapped IPv6 but returns the opposite verdict for the same host written as IPv4-compatible, 6to4 or NAT64.

Method: Roslyn syntax + semantics: methods that unwrap IPv4-mapped IPv6 and hand-roll IPv4 range carve-outs, checked for whether the IPv6 branch also accounts for the IPv4-compatible, 6to4 and NAT64 embeddings. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X15 · Unvalidated length from an untrusted reader10.0 / 10Exemplary○ Nothing flagged

Other · Security — Whether a length read out of the stream being parsed is bounded before it is allocated or read — an unchecked count taken from the input lets the input choose the allocation.

Method: Roslyn syntax + semantics: integer lengths read from a BinaryReader and spent on a bulk read or an array allocation, checked for any comparison or bounding call on the value anywhere in the method. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X16 · Unfloored truncation loop10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a loop that shortens a string until it fits a length budget has a floor — one with none grinds the value down to the empty string, or past it into a negative-length `Substring`.

Method: Roslyn syntax + semantics: while/do loops whose body's only effect on a string is to drop its last character, checked for whether anything — a direct comparison on the length, a body guard, a break — bounds that length below. On a repository with no .NET source it reads JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not) with the same rule: a `while`/`do` loop whose body’s one assignment to a value is `x = x.slice(0, -1)` or `x = x.slice|substring|substr(0, x.length - 1)`, driven by a condition that reads `x.length` only as a term of a larger expression — never compared directly, never tested for truthiness, and with no other read of `x` — and whose body has no `break`, `return`, `throw` or `if` naming `x`. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X17 · Uncapped recursion over a caller-supplied document10.0 / 10Exemplary○ Nothing flagged

Other · Security — Whether a walk that recurses through a JSON/XML tree handed in by its caller bounds how deep it will go — an uncapped walk lets the document's nesting choose the stack depth, and the resulting StackOverflowException cannot be caught.

Method: Roslyn syntax + semantics: methods that take a JSON/XML document node and call themselves with a child of it, reachable from an externally-callable member of the same type that accepts a document, checked for any depth parameter, descent counter or threaded arithmetic anywhere in the walk. On a repository with no .NET source it reads TypeScript off the engine’s own token stream (test, vendored, generated and minified paths and `.d.ts` not) with the same rule: a function or method with a parameter typed as a document value — `unknown`, `any`, `object`, `Record<string, unknown|any>`, a JSON alias (`JsonValue`, `JSONObject`, …) or a DOM node global the file does not rebind — that calls itself (bare, or through `this` for a method, or hands itself to a call over the value as in `value.map(walk)`) with something it took out of that value and never through an ancestor accessor such as `closest()` or `parentElement`, that is exported or reached from an exported function (a public method of the same exported class) taking such a value, and that names no depth, level, nesting, recursion, remaining or budget anywhere and threads no `+`/`-` arithmetic through a self-call. Plain JavaScript is not read: with no annotation nothing tells a parsed document from a tree the code built itself. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X18 · Disposal-pattern correctness10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a type's disposal matches what it OWNS — releasing what it created, leaving alone what it was handed, and not declaring a finalizer for state that has nothing unmanaged to finalize.

Method: Roslyn syntax + semantics: every assignment to a disposable field is read to decide whether the type CREATED the value or was handed it, and the type's disposal is checked against that answer — an injected interface it disposes, a value it constructed and never releases, a finalizer on a type holding nothing unmanaged, and a disposable local whose every reference is a plain member read. A value handed to a container that disposes its contents (a parent control's `Controls` collection, a component `IContainer`) is released by that container and is not reported; generated code is out of population. On a repository with no .NET source the same ownership questions are read in JavaScript/TypeScript off the engine’s own token stream (test, vendored, generated and minified paths not): a class declaring `dispose()`, `[Symbol.dispose]()` or `[Symbol.asyncDispose]()` that disposes a field it was handed through a constructor parameter typed as a repository interface or resolved by a dependency-injection container; that assigns a field only ever from `new X(…)` of a disposable class and neither releases it anywhere in the class nor names it in its disposal member or a method that member calls, nor hands it to anything else; and a `const`/`let` local built from literals only whose every reference opens a statement operating on a non-release member of it. A class is disposable when every repository declaration of its name declares or inherits a disposal member, or when it is a documented library disposable (`vscode` EventEmitter, CancellationTokenSource and Disposable; three.js geometries, materials, textures, render targets, renderers, controls and composers). The finalizer arm has no JavaScript counterpart: a class cannot declare one. Dart is read for the owned-and-never-released arm: a Flutter `State` (or a class declaring `dispose()`/`close()`) whose library-private field is written only with direct creations of a framework controller, `FocusNode`, `StreamController` or periodic `Timer` (or a `.listen(…)` into a field declared `StreamSubscription`), which nothing in the class or its library releases (`dispose`/`close`/`cancel`) and which is never handed on except as a named argument. Ruby is read for the owned-and-never-released arm and the abandoned-local arm: a class declaring an instance `close`, `dispose`, `shutdown`, `stop`, `disconnect` or `terminate` whose instance variable is written only with a blockless core descriptor creation (`File.open`/`new`, `Tempfile`, `Dir.open`, `IO.popen`, the `socket` and `openssl` socket classes) that no method of the class closes and that is never handed on (passed, returned, stored, exposed by `attr_reader`, delegated) — a class whose superclass or mixin lies outside the repository is not judged — and a blockless creation read through and dropped (`File.open(path).read`) or held in a local that is never closed, returned, passed or stored (a `&:read` block-pass, an `autoclose: false` borrow and a `fileno` hand-over are not abandonment). PHP is read for the same two arms: a class (not a trait, and not one using a trait) declaring an instance `close`, `dispose`, `shutdown`, `stop`, `disconnect` or `terminate` whose `private` property (or a `final` class's `protected` one) is written only with a direct core `fopen`, `tmpfile`, `popen`, `proc_open`, `fsockopen`, `stream_socket_client`/`server` or `opendir` that nothing in the class closes (`fclose`, `pclose`, `closedir`, `unset`, a reset to `null`) and that is never handed on, and a handle held in a function's local, or read through as the argument of a reader, that is never closed, returned, passed, captured or stored; a `php://` stream, `curl_init`, `SplFileObject`, `PDO` and a function the repository declares under the core name are not read. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X19 · Unrestored process-global state10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a method that temporarily changes state belonging to the whole process — the working directory, an environment variable — puts it back on EVERY path: a restore reached only when nothing throws leaks the change to the rest of the process.

Method: Roslyn syntax + semantics: method bodies that write the process working directory or an environment variable and write it back in the same body, checked for whether that restore sits in a `finally`/`catch` or only on the straight-line path. On a repository with no .NET source the same rule reads production JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not): `process.chdir`, `process.env.NAME =`/`["NAME"] =` and `delete process.env.NAME`, and Deno’s `Deno.chdir`/`Deno.env.set`/`Deno.env.delete`, paired per function body (a nested function or arrow is its own body, and module top-level code is none), where the last write puts back a local the body captured from the same global or deletes a variable the first write set, with at least one statement between them; a write in a `catch`/`finally` of that body silences it. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X20 · Mistyped argument guard10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether an argument guard throws the exception its own condition describes — a guard that rejects a value for being EMPTY and reports it as `NullPointerException` (Java, Kotlin, Scala), `ArgumentError.notNull` (Dart) or `ArgumentNullException` (F#'s `nullArg`) tells the caller a parameter was null when it provably was not.

Method: Roslyn syntax: `throw new ArgumentNullException(nameof(p))` statements controlled by an `if`, whose condition is read for a test that is true of a NON-null `p` — an emptiness test that dereferences it (`p.Count == 0`, `!p.Any()`) or a BCL predicate documented true of the empty value (`string.IsNullOrEmpty(p)`). Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X21 · Side-effecting pattern guard10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a `when` guard is free of side effects — a guard that increments a counter or assigns while deciding whether its arm matches applies that change during PATTERN MATCHING, on an arm that may not be selected, and skips it entirely when a short-circuit to its left answers first.

Method: Roslyn syntax: `when` guards on case labels and switch-expression arms, read for a mutation (`++`/`--`/assignment) sitting in a position the guard's own `&&`/`||`/`??`/`?:`/`?.` can skip. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X22 · Contradicted release guard10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a method that TAKES a lock or semaphore and gives it back from a flag-guarded `finally` returns the value that flag implies — reporting success while the guard hands the primitive back admits a second caller the exclusion was there to keep out, and reporting failure while the guard keeps it leaves nothing to ever give it back.

Method: Roslyn syntax: `try` statements whose `finally` releases a synchronisation primitive under a bare local-bool guard, where the method also TOOK that same primitive before the `try`, checked for a `return` of a bool literal whose value disagrees with the flag state the method's own straight-line assignments put it in. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X23 · Unguarded diagnostic materialisation10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether the work a diagnostic log line costs is paid only when that line is wanted — C# evaluates a call's arguments BEFORE the call, so a trace/debug message joined or projected out of a collection is built in full on every pass, and then discarded by a sink the shipped configuration leaves switched off.

Method: Roslyn syntax: log calls at a diagnostic level (a `Log`-prefixed method naming Trace/Debug/Verbose, or a bare `Debug`/`Trace`/`Verbose` on a receiver named for a logger), whose argument list is read for a call whose cost scales with a sequence — a LINQ operator, a materialisation, `string.Join`, a serializer — with no enclosing level check or conditional-compilation region. On a repository with no .NET source it reads JavaScript/TypeScript off the engine’s own token stream (test, vendored and minified paths not) with the same rule: a `debug`/`trace`/`verbose` call on a receiver named for a logger, or a `log`-prefixed method naming the level, whose argument calls an array operator (`map`/`filter`/`reduce`/`sort`/…), `Array.from`, `Object.keys/values/entries`, `JSON.stringify`/`util.inspect` over anything but a literal, or an array `join` — outside any arrow or function passed as an argument, which the logger calls only when the level is on — with no enclosing `if`, `&&` or `?:` whose condition names a level, a level string, or the `NODE_ENV`/`__DEV__`/`DEV` build switch. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X24 · Document value interpolated into markup unescaped10.0 / 10Exemplary○ Nothing flagged

Other · Security — Whether text read out of the document being converted is escaped before it is written into generated markup — a value the document's author chose, interpolated into an attribute the surrounding literal delimits, can close that attribute and open another.

Method: Roslyn semantic model over the whole compilation: a string-typed `Value`/`InnerText`/`InnerXml`/`Text` member declared inside `DocumentFormat.OpenXml` or `System.Xml` is a taint SOURCE, propagated through assignments, returns, arguments, tuple elements and string composition to its transitive closure, then read at interpolated-string holes that sit in a markup position the surrounding literal itself delimits. Escaper/encoder calls and enclosing validator conditions cut the flow. Flow- and container-insensitive by construction. A second arm needs no provenance at all and reports a type that CONTRADICTS ITSELF — the same expression escaped at one delimited markup hole and interpolated raw at another hole in the same markup position of the same type, which the type's own escaping proves is a defect without knowing where the value came from. On a repository with no .NET source it reads JavaScript/TypeScript off the token stream with the same rule: a DOM read of raw document text (`getAttribute`, `textContent`, `innerText`, `nodeValue`) is the source, propagated through local bindings and string composition, and judged at template-literal and concatenation holes in the same two delimited markup positions; escapers and validating conditions cut it, and documentation-site, test, vendored and minified scripts are not read. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X25 · Inert configuration knob10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a value the caller is invited to supply is the value the type actually uses — a constructor parameter stored in a private field that nothing ever reads while the default it was given is spelled out a second time at the site that should have read it, a keyed lookup that falls back to a different setting than the one its key names while the same type falls back to the matching one for that same key, or a culture-sensitive parse given no format provider by a type that feeds its own settable culture to the same kind of parse elsewhere, or a number an entry point writes to standard output under the host's culture while the same entry point formats with the invariant culture elsewhere. Either way, every caller who supplies a value silently gets something else.

Method: Roslyn syntax: private instance fields of a non-partial type assigned in a constructor from one of its own parameters with a `??` fallback, checked for whether anything in the type body reads the field and whether that same fallback expression is spelled out again outside the constructor; and `??` fallbacks onto a member access from a lookup call carrying exactly one string literal, grouped by that key across the type and checked for a fallback member whose folded name disagrees with the key while a sibling site for the same key agrees with it. On a repository with no .NET source the first two arms read JavaScript/TypeScript off the engine’s own token stream (tests included, bundles and vendored paths not): a `#x`, `private` or `private` parameter-property instance field filled in the constructor from a parameter (or one member of one) through `??`/`||` or a parameter default, never read anywhere in the file by name, whose constructed default is spelled again in the class body; and `lookup("key") ?? s.member` grouped by key per class, or per module outside every class. The culture arm has no JavaScript counterpart: its parses take no locale. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X26 · Unsynchronised callback handoff10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a value handed from a callback to the body that waits on it crosses on something built to be crossed — a `Queue<T>`/`List<T>`/`Dictionary<K,V>` written inside an event handler and read back outside it is mutated by two flows at once, and the semaphore or completion source beside it orders how MANY items exist while leaving the collection's own head, tail and backing array unprotected.

Method: Roslyn syntax: method, accessor, local-function and lambda bodies that declare BOTH a non-thread-safe generic collection (`Queue`/`Stack`/`List`/`Dictionary`/`HashSet`/`Sorted*`/`LinkedList`) and a synchronisation primitive (`SemaphoreSlim`/`TaskCompletionSource`/`ManualResetEvent(Slim)`/`AutoResetEvent`/`CountdownEvent`) as locals, then read for a `+=`-registered lambda that raises that primitive while the body outside every lambda waits on it — and, in that scope, a mutating call on the collection inside the lambda paired with a mention of it outside. Any `lock` in the scope abstains it. On a repository with no .NET source the same handoff is read in Java off the engine’s own token stream (test source sets, vendored and demonstration paths not): an `ArrayList`/`LinkedList`/`ArrayDeque`/`PriorityQueue`/`Hash*`/`LinkedHash*`/`Tree*` local and a `CountDownLatch`/`Semaphore`/`CompletableFuture` local, a lambda or anonymous class that raises the primitive and mutates the collection, and a wait outside it; any `synchronized` or `lock()` abstains the body. Because each of those primitives orders what the callback wrote before raising it, only a touch that provably overlaps the callback is convicted: one after the registration and before the next wait, or one in a loop registered-before, waiting on every pass and not declaring the collection. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X27 · Collection changed while being enumerated10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether an enhanced `for` leaves the collection it is walking alone — a body that adds to or removes from the very collection the loop is iterating invalidates the fail-fast iterator it is holding, so the next `next()` throws `ConcurrentModificationException` and the remaining elements are never seen. Whether a `for` comprehension or `foreach` leaves the mutable collection it is walking alone — an `ArrayBuffer` or `ListBuffer` counts its changes and its iterator checks the count, an `ArrayDeque` (and `mutable.Queue`/`mutable.Stack`) is walked by index up to its starting length, and a `java.util` collection walked through `asScala` is fail-fast, so a body that adds to or removes from the very collection the loop is walking makes a later step throw `ConcurrentModificationException` (`IndexOutOfBoundsException` for a deque) and the remaining elements are never seen.

Method: Roslyn syntax + semantics: `foreach` statements whose body calls a structural mutator (`Add`/`Remove`/`Clear`/`Insert`/…) on the very expression the loop is enumerating. Two arms. ARM A — the source is a concrete fragile BCL collection, or a live `Keys`/`Values` view over one, and the mutator resolves to that same collection's own member; concurrent and immutable collections and arrays are outside the population by construction, since their enumerators survive a structural change. ARM B — the source is an argument-less accessor CALL on a receiver whose body is in source: the accessor must return a stored field VERBATIM and a sibling member must structurally change that same field, both read off the implementations rather than from the members' names. A mutation the loop provably exits immediately after (`break`/`return`/`throw`/`goto`), or one written inside a nested loop or a lambda, is counted and never reported. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X28 · Index access outside its own emptiness guard10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a condition that tests a value for emptiness indexes that same value only where the test holds — an `||` written one parenthesis too far to the left leaves an index access outside the guard beside it, so the empty case the guard exists to anticipate reaches the index and throws.

Method: Roslyn syntax only, no semantic model: the OUTERMOST `&&`/`||` of every boolean condition, read for a symbol the condition tests for emptiness (`string.IsNullOrEmpty`/`IsNullOrWhiteSpace`, a `Length`/`Count` comparison against a literal, `Any()`, a `Length`/`Count` pattern, or a comparison against `""`) and ALSO indexes. Each `symbol[...]` access is placed by a boolean-reachability walk from the access up to the outermost connective: an access is COVERED when some enclosing step has it in the right operand and the left operand, under the truth value that step forces, proves the symbol non-empty — a recursion over `&&`/`||` whose true- and false-directions are asymmetric. A finding needs BOTH an uncovered access and a covered one on the same symbol in the same condition, which is the agreeing twin that separates a misplaced parenthesis from an unrelated length test. Bare index accesses with no emptiness test in the condition are neither counted nor reported; a non-identifier receiver and a lambda nested inside the condition are outside the population. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X29 · Per-element action decided by a fixed element10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a decision taken once per element is taken ABOUT that element — a test inside a counted loop that reads a fixed subscript of the very collection its guarded statement indexes by the loop variable applies element zero's answer to all of them, so the elements that differ from it are all handled wrongly, and in the same direction.

Method: Roslyn syntax only, no semantic model: every `for` statement declaring exactly ONE loop variable, and every `if` inside its body that is not under a nested loop or a lambda. A site enters the population when the `if`’s condition never mentions the loop variable while the statement it guards indexes some collection by that variable ALONE (`c[i]`; `c[i + 1]` and `c[i, j]` are outside it). A finding additionally needs the AGREEING TWIN at the same-collection grain: the condition must read THAT SAME collection at a subscript that does not move — written into the condition, or reached through a local declared BEFORE the loop, so an alias bound inside the body is not followed. Both collection expressions must be simple identifiers. On a repository with no .NET source the same rule reads JavaScript/TypeScript off the engine’s own token stream (tests included, bundles and vendored paths not): a `for (let|var|const x = …; …; …)` with one declarator and a braced body, an alias followed only when it is declared before the loop in a block that encloses it and never assigned inside the loop. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X3 · Exception handling5.4 / 10Adequate✓ Tool-verified

Other · Code Health — Whether exceptions are handled rather than silently swallowed or rethrown with lost stack traces.

Method: Roslyn syntax scan: every catch clause counted; empty catches and bare rethrows flagged. Population is all catch clauses, not estimated. Deterministic, hard fact.

`case _: Throwable` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter. (×5) — testkit/shared/src/main/scala/cats/effect/testkit/TestInstances.scala:187, std/js/src/main/scala/cats/effect/std/SecureRandomCompanionPlatform.scala:100, core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:106, …
An empty catch block silently discards the error — failures vanish with no log and no rethrow. Log it, handle it, or don't catch it. (×5) — core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:121, core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:138, core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:154, …
`catch (Throwable)` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter. — core/jvm/src/main/java/cats/effect/IOFiberConstants.java:56
`catch (Exception)` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter. (×2) — core/jvm/src/main/java/cats/effect/Signal.java:84, core/jvm/src/main/java/cats/effect/Signal.java:98

What to do

Swallowed exception (caught, then discarded)

Do you agree with this assessment?

X30 · Support guard that admits what it rejects10.0 / 10Exemplary○ Nothing flagged

Other · Code Health — Whether a guard written as a NEGATED `||` says what its author meant — `!(a || b || x != k)` is `!a && !b && x == k` by De Morgan, so a bail-out that mixes capabilities the code needs with a fault it refuses turns inside out: it fires only where the capabilities are ABSENT, and lets every value the fault term names walk straight into the body that cannot handle it.

Method: Roslyn syntax only, no semantic model: every logical-not whose operand is a parenthesised `||` chain of two or more disjuncts, flattened (a left-nested `a || b || c` read once would see `(a || b)` as one disjunct). A site enters the population on that shape alone. A finding additionally needs the disjuncts to DISAGREE in polarity: at least one bare boolean read — an identifier or member access, never an invocation, which is a predicate rather than a capability flag — and at least one `x != <constant>`, the only form that negates into an exact-value pin (`== null` negates into a looser requirement and is outside the fault set). Consistently-polarised disjunctions, all-fault or all-capability, are counted and never reported; a negated `&&` is outside the population entirely. No same-receiver gate: it was measured to cost a real defect and remove no false positive. Deterministic, provable per finding. Advisory.

Do you agree with this assessment?

X5 · Nullable reference types2.0 / 10Critical✓ Tool-verified

Other · Code Health — Whether Scala's null is held to the type system and not undermined by assertions — a file compiled with `-Yexplicit-nulls` is one where `String` excludes null and `String | Null` admits it, a file under WartRemover's `Null` wart or Scalafix's `DisableSyntax.noNulls` is one whose code cannot write `null` and must say `Option`, and each `.nn`, `import scala.language.unsafeNulls` or null-lint suppression is the author overruling that.

Method: Roslyn compiler-options scan: NullableContextOptions per project; null-forgiving (!) suppression density per 1k syntax nodes. Deterministic, adoption plus suppression penalty.

No build over this repository's 280 Scala product file(s) passes `-Yexplicit-nulls`, enables WartRemover's `Null` wart or runs Scalafix's `DisableSyntax.noNulls`, so every reference type admits null and nothing reports a `null` written into the code or returned from a Java API — the first one to reach a method call is a `NullPointerException`. `Option` by convention is a habit no tool here holds the code to.

What to do

On Scala 3, add `-Yexplicit-nulls` to `scalacOptions` so `String` and `String | Null` mean different things, and type each Java API's result as nullable where it can return null; on Scala 2 (or as a first step), enable WartRemover's `Null` wart (`wartremoverErrors += Wart.Null`) or Scalafix's `DisableSyntax.noNulls = true` so the code holds absence in `Option`. Then pay the assertions down rather than adding to them: each `.nn` is a null the compiler could not rule out — wrap the Java value in `Option(…)` at the boundary, pattern-match on `null` once there, or change the API so the null cannot arrive; an `unsafeNulls` import switches the checking off for everything after it.

Do you agree with this assessment?

Reference — by lens

The score is the rank-weighted fold of these lenses (worst-heaviest), each including its meta-dimensions; a lens with a Critical contributor is capped at Fair (its band reads "gated by …") and is never the strongest area however high its average.

Lens	Score	Rating	Impact
Code Health	60%	Adequate — gated by X5	Capped at Fair by a Critical contributor — resolve it before relying on this lens.
Architecture	91%	Adequate — gated by D26	Capped at Fair by a Critical contributor — resolve it before relying on this lens.
Maturity	63%	Adequate — gated by M2	Capped at Fair by a Critical contributor — resolve it before relying on this lens.
Readiness	57%	Adequate — gated by P2	Capped at Fair by a Critical contributor — resolve it before relying on this lens.
Security	78%	Adequate — gated by D36	Capped at Fair by a Critical contributor — resolve it before relying on this lens.
Performance	72%	Strong	Strongest area.

Unscored — 1 check(s) recorded observations but carry no score

These checks ran and found something, but they do not carry a score — either by design (an advisory check reports evidence rather than grading it) or because they could not be scored here. They are excluded from the score for that reason, not because there was nothing to see.

X10 Duplicated predicate — 2 observation(s) recorded · Advisory — this card reports evidence and never carries a score.

Not evidenced — 2 control(s) we could not find positive evidence for

These checks grade a working control, and the repository shows no evidence of one. That is deliberately not scored as a zero: a repository cannot show an ops runbook, a database TTL or an infrastructure-side audit log, so absence of evidence here is not evidence the control is missing. It is also not a statement that the check is irrelevant to this codebase — the thing it grades applies; we just could not see it. Excluded from the score either way.

P4 Deployment & Rollback — not evidenced — no deploy/rollback/approval signal in the repo; absence of evidence is not evidence of a manual release
P5 DR & Backup — not evidenced — repo shows no backup/RTO/RPO controls; absence of evidence is not evidence of a working control

Not included — 56 check(s) not relevant to this codebase

These checks had nothing to measure here (no tests, no git history, the codebase is small, or the architecture style doesn't apply), so they're omitted above rather than scored low.

AC1 Text alternatives — No web markup found — accessibility is not applicable to this repository.
AC2 Forms & labels — No web markup found — accessibility is not applicable to this repository.
AC3 Page structure — No web markup found — accessibility is not applicable to this repository.
AC4 Keyboard semantics — No web markup found — accessibility is not applicable to this repository.
AC5 ARIA correctness — No web markup found — accessibility is not applicable to this repository.
AC6 Visual & motion safety — No web markup found — accessibility is not applicable to this repository.
AC7 A11y enforcement — No web markup found — accessibility is not applicable to this repository.
AX1 Captive dependencies — Not applicable: this repository's Java imports no dependency-injection container and defines no container of its own — nothing that both registers and resolves bindings, and nothing that names two lifetimes — so nothing holds one lifetime's instance while handing out another's; this repository's Scala imports no dependency-injection container and defines no container of its own — nothing that both registers and resolves bindings, and nothing that names two lifetimes — so nothing holds one lifetime's instance while handing out another's.
AX2 Stateful singletons — No container singleton was found, so there is no shared instance for concurrent requests to race on. No class in this Java code is a Spring, JSR-330 or CDI singleton bean. No class in this Scala code is a Play controller, a Cask routes object, a Scalatra servlet, a Finatra controller, an Akka/Pekko HTTP routes holder or a JSR-330/Spring singleton, so no instance is shared between request threads.
AX5 Architecture & structure — not assessed — architecture style/structure is computed from a project graph (projects, types, module namespaces) that was not loaded for this repository, because the repository is written in a language this check does not yet model, or because its projects failed to load. This is a gap in the analyzer, not a finding about this repository
AX7 Slice cohesion — not applicable — not a vertical-slice architecture
AX9 CQS / query purity — no CQRS query handlers detected — query purity is not applicable to this codebase
AXB1 Runtime evidence locked — no reproducible boot — This repository has nothing the runtime tiers could boot or serve — no markup, no UI framework or web-server dependency, no UI component source, no native UI project and no API definition — nothing here is a surface to boot — so runtime a11y/egress/header evidence has no subject here. Not applicable: this is neither a gap in the scan nor a finding about your code.
C1 Data Protection — Not assessed: these personal data controls are read from a source model (declarative annotations, request middleware, entity/column names, guard methods) that was not loaded for this repository — because the repository is written in a language this check does not yet model, or because its projects failed to load. Absence of an idiom this check recognises is NOT evidence that this repository lacks personal data controls: it may implement them entirely in its own ecosystem. This is a gap in the analyzer's language coverage, not a finding about this repository.
C2 Access Controls — Not assessed: these authorization controls are read from a source model (declarative annotations, request middleware, entity/column names, guard methods) that was not loaded for this repository — because the repository is written in a language this check does not yet model, or because its projects failed to load. Absence of an idiom this check recognises is NOT evidence that this repository lacks authorization controls: it may implement them entirely in its own ecosystem. This is a gap in the analyzer's language coverage, not a finding about this repository.
C3 Audit Trail — No personal data detected in a persisted data model — no PII-named column (email, first_name, date_of_birth, phone_number, …) or stored credential on a Slick table or in a SQL migration's CREATE TABLE or ALTER TABLE — and no database client (Slick, Doobie, Quill, ScalikeJDBC, Anorm, Skunk, a MongoDB or Cassandra driver, JDBC) imported either, so this repository keeps no sensitive data whose changes an audit trail would record. If it does (through a store configured outside this repository, for instance), the trail belongs to wherever that data is stored.
C4 Data Retention — No personal data detected in a persisted data model — no PII-named field (email, firstName, dateOfBirth, phoneNumber, …) or stored credential on a Slick table or in a SQL migration's CREATE TABLE or ALTER TABLE — and no database or data-store client (Slick, Doobie, Quill, ScalikeJDBC, Anorm, Skunk, JDBC, MongoDB, Cassandra, …) imported either, so this repository keeps no personal data whose lifetime a retention limit would bound.
C5 Data-Subject Rights — No personal data detected in a persisted data model — no PII-named field (email, firstName, dateOfBirth, phoneNumber, …) or stored credential on a Slick table or in a SQL migration's CREATE TABLE or ALTER TABLE — and no database or data-store client (Slick, Doobie, Quill, ScalikeJDBC, Anorm, Skunk, JDBC, MongoDB, Cassandra, …) imported either, so this repository keeps no personal data for a data subject to erase, export or consent over.
D10 Test Quality — ~18171 lines of test source are present (.scala) but no test cases reached the test census for this repository — no test root we could resolve declared them, or the files we read declare no cases in a test framework we recognise — so skipped/assertion-free tests couldn't be counted. Not scored — this is a gap in the analyzer, not a finding about this repository.
D11 Test Reliability — Test reliability not included — the .scala suite was found but not re-run
D12 Dependency Hygiene — Dependency currency not established — this repository declares no production dependency to grade
D14 License Compliance — sbt licences not graded — no production declaration in build.sbt carries a literal version
D18 Solution Shape — D18 scores the shape of a .NET solution; this repository has no .NET solution or project files, so the dimension does not apply.
D21 Naming Consistency — Naming consistency is measured on C# only; Java, Scala not measured.
D22 Internal API Consistency — The exposed public-API surface could not be collected — no C#/VB projects loaded.
D23 Boundary Type-Coupling — No bounded-context organisation was detected either — neither a context-shaped layout, nor 2+ sibling source directories each declaring an aggregate root, nor 2+ projects each declaring an entity of their own. Declaring this codebase's bounded contexts (≥2) would let cross-boundary type coupling be assessed. Declare them in `.codehealth/config.yaml` at the repository root (create it if absent), mapping each context name to the module-path or namespace prefixes that belong to it — e.g. `architecture:` → `contexts:` → `Billing: ["src/billing", "Acme.Billing"]`, `Catalog: ["src/catalog", "Acme.Catalog"]`.
D24 Comment Value — D24 reads C# and Visual Basic comments only — this repository's production source is .java, .scala, which was left unread. Not scored: this is a gap in the analyzer, not a verdict about this repository.
D25 ADR Conformance — no ADRs to check
D27 Navigability — D27 counts a call into the standard library or a dependency as unresolved for this repository's language (.scala), so too few call sites counted as resolved to assess navigability. Not scored: this is a gap in the analyzer, not a verdict about this repository.
D31 IaC & Container Security — No Infrastructure-as-Code or container manifests found (Dockerfile, Docker Compose, Terraform, Kubernetes/Helm, CloudFormation, ARM, Bicep, Ansible); nothing to scan.
D32 Data Compliance (PII/GDPR) — No personal data was found crossing a boundary the PII/GDPR ruleset checks — nothing written to a log or console sink, placed in a URL or query string, or persisted to browser storage. That is a clean result for the LEAK surface only: this ruleset detects personal data escaping, it does not inventory the personal data a repository holds, so it is not evidence that this repository has no personal-data surface. The personal-data map (Appendix C) and the C1-C5 compliance cards are what speak to that.
D34 Knowledge Freshness — knowledge concentrated in recent work — freshness signal contradicted by repo activity
D37 Vulnerability-disclosure Policy — No vulnerability-disclosure policy file found (SECURITY.md/.markdown/.rst/.txt at root or under .github/.forgejo/.gitea/docs, .well-known/security.txt). A coordinated-disclosure policy may live off-repo, so this is not evidenced rather than failed.
D39 IL Efficiency — D39 measures the IL emitted by a .NET build; this repository has no .NET solution or project files, so the dimension does not apply.
D40 Network Egress Confinement — No Kubernetes/orchestration workloads found in the repository manifests; network egress policy is a cluster-native control that may live at the platform/firewall layer, so there is nothing to assess here.
D41 Kernel & Syscall Confinement — No Kubernetes/orchestration workloads found in the repository manifests; seccomp/AppArmor/SELinux confinement is a workload-level control, so there is nothing to assess here.
D42 Runtime Threat Enforcement — No Kubernetes/orchestration workloads found in the repository manifests; runtime threat-detection and admission-control policy are cluster-level controls, so there is nothing to assess here.
D44 Platform End-of-Life — Platform end-of-life not assessed — this repository declares no platform this pass reads
D7 Architectural Integrity — no checkable ADRs, and no project-reference graph for the cycle pass to read — so this dimension makes no claim about dependency cycles in either direction (where this repository's language has an import-cycle lens, cycles are reported there). Architectural integrity not assessed
D8 Code Coverage — Coverage not included — suite not readable by the collector
DM1 Domain Modelling — applicable but not scored (2 signals for this style, 2 needed — the count is met but a required primary signal is absent): 101 value object(s); 4 domain event(s); its domain events are published by services or handlers — no domain entity raises one
ED1 Event-Driven — not scored — this repository shows none of the 3 signals this lens looks for
ED5 Idempotency — no mutating command handlers or message consumers detected — idempotency check not applicable
ES1 Event Sourcing — not scored — this repository shows none of the 3 signals this lens looks for
P12 CI test-gate honesty — Reported, not scored — and nothing was matched here. The coverage check applies to any stack, and the automatic-re-run check to any GitHub-Actions workflow, but the checks for excluded tests, skipped tests and sleep-based synchronisation currently recognise only some ecosystems' test-runner idioms, so on a repository built with another stack the zeros below mean 'not checked', not 'clean'.
P7 Outbound HTTP resilience — not applicable — no HTTP server, API framework or worker entry point was found in the JVM source, so there is no service whose uptime a failing dependency could take down
P8 Schema migrations — no ORM, schema-migration tool or schema auto-create was found in this repository's dependency manifests or source, so there is no database schema for this check to judge
P9 Domain vs controller coverage — no coverage report found on disk — produce a coverage report in a standard format (`addSbtPlugin("org.scoverage" % "sbt-scoverage" % "<version>")` in `project/plugins.sbt`, then `sbt clean coverage test coverageReport`) and commit it — a hosted scan measures a clone of the repository, so a report that exists only in a working tree, a CI runner's or your own, never reaches it; the artefact is commonly gitignored, so `git add -f` that one file (or un-ignore its path) and commit it alongside the code it measures, or wire coverage collection into CI, to enable this cross-layer check
S1 Web-Security Posture — No web surface: 287 Scala file(s) were read for weak hashes and ciphers, key material fixed in the source, disabled TLS certificate validation and obsolete TLS versions, and none was found. This repository serves no HTTP of its own — no HTTP-server artifact (akka-http, pekko-http, http4s, Play, Finagle, zio-http, cask, Scalatra, a tapir server, Jetty, Undertow, …) outside test scope in its build, and no server package imported or server bound in its production source — so HTTPS enforcement, HSTS, cookie flags and input validation are N/A here, as they are for a C# library or worker. If this codebase starts serving HTTP, the dimension reactivates automatically.
SC1 Supply-chain hygiene — Advisory — this card reports evidence and never carries a score, so there is nothing missing here.
X2 Cancellation propagation — no C# was loaded; this repository's Scala and Java were read, and no request in it can be cancelled by a caller — a Scala request takes no token: a Future cannot be cancelled, and cats-effect, ZIO and Monix interrupt the fiber that made the request from outside the call, not through a parameter; a Java request off Android takes no token: it is cancelled through the handle it returns (Future.cancel, Call.cancel, a Disposable), ambiently (io.grpc.Context) or by interrupting its thread, not through a parameter
X32 Type resolved by simple name across every loaded assembly — This check is about how a .NET program searches the assemblies loaded into its process for a type, and this repository contains no .NET source, so there is nothing here for it to assess. Not a gap in the analyzer and not a finding about your code.
X4 Structured logging — This check asks whether log calls keep a message's values apart from its text, which needs a logger that can carry them as fields. This repository's Java was read, and it logs through none that an assembled message defeats: java.util.logging's level methods, log4j 1, commons-logging, JBoss Logging and Flogger take one finished message (as log4net does in C#), or it makes no call through a named logger at all. Calls made through SLF4J or log4j 2 (`org.slf4j.Logger`, `org.apache.logging.log4j.Logger`, Lombok's `@Slf4j`) would be judged.
X6 Hand-rolled structured-format parsing — Advisory — this card reports evidence and never carries a score, so there is nothing missing here.
X7 Silent fallback defaults — Advisory — this card reports evidence and never carries a score, so there is nothing missing here.
X9 Subsumed condition operand — Advisory — this card reports evidence and never carries a score, so there is nothing missing here.

Appendix A — Findings (grouped)

The findings behind the scores, grouped by severity, then by dimension and kind. The high-severity issues are enumerated in full below; items per group are capped at 25 with any overflow stated explicitly per group, never silently truncated. The complete machine-readable list of every finding (all severities) is the companion findings.md in this report's bundle.

Critical — 37 finding(s)

D29 · Static Analysis (SAST) · REDACTED

REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
REDACTED
+ 10 more in this group — see findings.md.

D29 · Static Analysis (SAST) · REDACTED · ×1

REDACTED

D29 · Static Analysis (SAST) · REDACTED · ×1

REDACTED

Serious — 151 finding(s)

D17 · Explicit Debt · TodoComment · ×34

TodoComment tests/shared/src/test/scala/cats/effect/tracing/TraceSuite.scala:25 — // TODO reenable this test on non-WSL JS platforms when scala-js/scala-js#5331 is fixed (breaks on Chrome)
TodoComment tests/shared/src/test/scala/cats/effect/kernel/RefSuite.scala:29 — // TODO need parallel instance for IO — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment tests/jvm-native/src/test/scala/cats/effect/std/DeferredParallelismSuite.scala:128 — // TODO move this back to run on both JVM and JS once we have a better test — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment tests/jvm-native/src/test/scala/cats/effect/std/DeferredParallelismSuite.scala:153 — // TODO this code is now in 4 places; should be in 1 — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment testkit/shared/src/main/scala/cats/effect/testkit/TestInstances.scala:63 — // TODO dedup with FreeSyncGenerators — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment testkit/shared/src/main/scala/cats/effect/testkit/TestInstances.scala:89 — // todo: enable racePair after MVar been made serialization compatible — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment std/shared/src/main/scala/cats/effect/std/Dispatcher.scala:204 — // TODO decide if we want other people to use this — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment std/shared/src/main/scala/cats/effect/std/Queue.scala:744 — // TODO could optimize notifications by checking if buffer is completely empty on put — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment std/shared/src/main/scala/cats/effect/std/Queue.scala:1023 — // TODO tunable — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment laws/shared/src/main/scala/cats/effect/laws/MonadCancelLaws.scala:42 — // TODO F.uncancelable(p => F.canceled >> p(fa) >> fb) <-> F.uncancelable(p => p(F.canceled >> fa) >> fb) — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/Generators.scala:38 — // todo: uniqueness based on... names, I guess. Have to solve the diamond problem somehow — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/Generators.scala:199 — // TODO we can't really use poll :-( since we can't Cogen FunctionK — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/TimeT.scala:114 — // TODO this doesn't work (yet) because we need to force the "faster" effect to win the race, which right now isn't happening — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/TimeT.scala:137 — // TODO is there anything better here? — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/pure.scala:365 — // todo: MVar is not Serializable, release then update here — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment ioapp-tests/src/test/scala/IOAppSuite.scala:50 — // TODO probably doesn't work — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment ioapp-tests/src/test/scala/IOAppSuite.scala:248 — // TODO reenable this test (#3919)
TodoComment core/shared/src/main/scala/cats/effect/IOFiber.scala:1378 — // TODO figure out if the JVM ever optimizes this away — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment core/native/src/main/scala/cats/effect/IOApp.scala:298 — // TODO — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment benchmarks/src/main/scala/cats/effect/benchmarks/AsyncBenchmark.scala:78 — // TODO — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala:469 — // TODO: should this be in scala-native? — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala:471 — // TODO: this might be platform-dependent — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala:472 — // TODO: this might be platform-dependent — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment core/native/src/main/scala/cats/effect/unsafe/IORuntimeConfigCompanionPlatform.scala:24 — // TODO make the cancelation and auto-yield properties have saner names — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
TodoComment core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeConfigCompanionPlatform.scala:25 — // TODO make the cancelation and auto-yield properties have saner names — source code is not a task system: move the work to your tracker and leave a reference instead (e.g. `// REF: #123`), so the task is planned where tasks live and the ticket links back to the code.
+ 9 more in this group — see findings.md.

X3 · Exception handling · Swallowed exception (caught, then discarded) · ×8

Swallowed exception (caught, then discarded) testkit/shared/src/main/scala/cats/effect/testkit/TestInstances.scala:187 — `case _: Throwable` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.
Swallowed exception (caught, then discarded) std/js/src/main/scala/cats/effect/std/SecureRandomCompanionPlatform.scala:100 — `case _: Throwable` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.
Swallowed exception (caught, then discarded) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:106 — `case _: Throwable` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.
Swallowed exception (caught, then discarded) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:299 — `case _: Throwable` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.
Swallowed exception (caught, then discarded) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:318 — `case _: Throwable` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.
Swallowed exception (caught, then discarded) core/jvm/src/main/java/cats/effect/IOFiberConstants.java:56 — `catch (Throwable)` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.
Swallowed exception (caught, then discarded) core/jvm/src/main/java/cats/effect/Signal.java:84 — `catch (Exception)` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.
Swallowed exception (caught, then discarded) core/jvm/src/main/java/cats/effect/Signal.java:98 — `catch (Exception)` takes every exception and records none of it — the body neither logs it, rethrows it, nor even names it, so the failure is discarded as completely as by an empty catch and only the substituted value survives. Log it through whatever this codebase already uses to report problems, narrow the catch to the exception this call can actually raise, or say in a comment on the catch why the failure genuinely cannot matter.

D3 · God Classes · TooManyMethods · ×6

TooManyMethods: IO core/shared/src/main/scala/cats/effect/IO.scala:117 — TooManyMethods — 95 methods. The bar is 30 methods; this is 65 over it, 3.17× the bar. To reduce it, group the members that share the same data into a smaller type of their own and delegate to it, so no single type carries every responsibility.
TooManyMethods: IO core/shared/src/main/scala/cats/effect/IO.scala:1202 — TooManyMethods — 72 methods. The bar is 30 methods; this is 42 over it, 2.40× the bar. To reduce it, group the members that share the same data into a smaller type of their own and delegate to it, so no single type carries every responsibility.
TooManyMethods: IOFiber core/shared/src/main/scala/cats/effect/IOFiber.scala:68 — TooManyMethods — 37 methods. The bar is 30 methods; this is 7 over it, 1.23× the bar. To reduce it, group the members that share the same data into a smaller type of their own and delegate to it, so no single type carries every responsibility.
TooManyMethods: Resource kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala:153 — TooManyMethods — 34 methods. The bar is 30 methods; this is 4 over it, 1.13× the bar. To reduce it, group the members that share the same data into a smaller type of their own and delegate to it, so no single type carries every responsibility.
TooManyMethods: Resource kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala:805 — TooManyMethods — 34 methods. The bar is 30 methods; this is 4 over it, 1.13× the bar. To reduce it, group the members that share the same data into a smaller type of their own and delegate to it, so no single type carries every responsibility.
TooManyMethods: Poller core/jvm/src/main/scala/cats/effect/unsafe/SelectorSystem.scala:161 — TooManyMethods — 33 methods. The bar is 30 methods; this is 3 over it, 1.10× the bar. To reduce it, group the members that share the same data into a smaller type of their own and delegate to it, so no single type carries every responsibility.

D3 · God Classes · FileTooLong · ×6

FileTooLong: effect/IOFiber.scala core/shared/src/main/scala/cats/effect/IOFiber.scala — FileTooLong — 879 significant lines (blank, comment-only and punctuation-only lines excluded), about 93% of them inside a single declaration: IOFiber (68-1572). The bar is 500 significant lines; this is 379 over it, 1.76× the bar. Moving the declarations that sit BESIDE it into sibling files will not shorten this file. Extract from INSIDE that declaration instead: lift each cohesive group of its body — the parts that share the same inputs and are named together — into its own unit in a sibling file, and have the original call them.
FileTooLong: effect/IO.scala core/shared/src/main/scala/cats/effect/IO.scala — FileTooLong — 738 significant lines (blank, comment-only and punctuation-only lines excluded). The bar is 500 significant lines; this is 238 over it, 1.48× the bar. To reduce it, split the file along the responsibilities already in it: move each cohesive group of declarations into its own sibling file in the same module or package, so no one file has to be read whole to change one of them.
FileTooLong: kernel/Resource.scala kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala — FileTooLong — 708 significant lines (blank, comment-only and punctuation-only lines excluded). The bar is 500 significant lines; this is 208 over it, 1.42× the bar. To reduce it, split the file along the responsibilities already in it: move each cohesive group of declarations into its own sibling file in the same module or package, so no one file has to be read whole to change one of them.
FileTooLong: std/Queue.scala std/shared/src/main/scala/cats/effect/std/Queue.scala — FileTooLong — 641 significant lines (blank, comment-only and punctuation-only lines excluded). The bar is 500 significant lines; this is 141 over it, 1.28× the bar. To reduce it, split the file along the responsibilities already in it: move each cohesive group of declarations into its own sibling file in the same module or package, so no one file has to be read whole to change one of them.
FileTooLong: unsafe/WorkerThread.scala core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala — FileTooLong — 517 significant lines (blank, comment-only and punctuation-only lines excluded). The bar is 500 significant lines; this is 17 over it, 1.03× the bar. To reduce it, split the file along the responsibilities already in it: move each cohesive group of declarations into its own sibling file in the same module or package, so no one file has to be read whole to change one of them.
FileTooLong: kernel/MonadCancel.scala kernel/shared/src/main/scala/cats/effect/kernel/MonadCancel.scala — FileTooLong — 510 significant lines (blank, comment-only and punctuation-only lines excluded). The bar is 500 significant lines; this is 10 over it, 1.02× the bar. To reduce it, split the file along the responsibilities already in it: move each cohesive group of declarations into its own sibling file in the same module or package, so no one file has to be read whole to change one of them.

X3 · Exception handling · Swallowed exception (empty catch) · ×5

Swallowed exception (empty catch) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:121 — An empty catch block silently discards the error — failures vanish with no log and no rethrow. Log it, handle it, or don't catch it.
Swallowed exception (empty catch) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:138 — An empty catch block silently discards the error — failures vanish with no log and no rethrow. Log it, handle it, or don't catch it.
Swallowed exception (empty catch) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:154 — An empty catch block silently discards the error — failures vanish with no log and no rethrow. Log it, handle it, or don't catch it.
Swallowed exception (empty catch) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:168 — An empty catch block silently discards the error — failures vanish with no log and no rethrow. Log it, handle it, or don't catch it.
Swallowed exception (empty catch) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:182 — An empty catch block silently discards the error — failures vanish with no log and no rethrow. Log it, handle it, or don't catch it.

D4 · Code Duplication · Duplicated block (6 lines × 2) · ×4

Duplicated block (6 lines × 2) core/js/src/main/scala/cats/effect/ByteStack.scala:42 — core/js/src/main/scala/cats/effect/ByteStack.scala:42-47 | core/jvm-native/src/main/scala/cats/effect/ByteStack.scala:63-68 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere both call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made twice. Read the line range as the matched WINDOW rather than a finished unit: at `core/js/src/main/scala/cats/effect/ByteStack.scala:42` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (6 lines × 2) laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:38 — laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:38-43 | laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:69-74 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:38` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (6 lines × 2) laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:49 — laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:49-54 | laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:80-85 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `laws/shared/src/main/scala/cats/effect/laws/GenSpawnLaws.scala:49` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (6 lines × 2) std/shared/src/main/scala/cats/effect/std/PQueue.scala:46 — std/shared/src/main/scala/cats/effect/std/PQueue.scala:46-51 | std/shared/src/main/scala/cats/effect/std/Queue.scala:53-58 — the copies sit in sibling files of one directory, so a shared home is within easy reach: extract the block into a single shared function the call sites can all reach — a file they already depend on, or a new one alongside them — and call it from both call sites, so a change lands once. Each matched range is the entire body of the declaration above it, so the region is already a complete unit: move that whole declaration to the shared location and have each site call it, rather than lifting the lines out of their bodies. Any `return` inside it is the body's own exit and keeps its meaning in the moved unit.

D6 · Cohesion (LCOM4) · Low cohesion · ×4

Low cohesion: IORuntimeBuilder (LCOM4 9) core/shared/src/main/scala/cats/effect/unsafe/IORuntimeBuilder.scala:26 — IORuntimeBuilder's methods fall into 9 groups that share no field and call none of each other, against a bar of more than 3 for this run (LCOM4, configurable — your repository's bar is the one quoted here). Each group is a set of methods reachable from one another through shared fields or direct calls, so 9 groups means the type has that many internally-connected clusters with nothing tying them together. Types whose shape makes a high count expected — and which would otherwise dominate this list — are excluded before this row is raised, so this is a genuine split candidate rather than a metric reading. It is still a shape, not a defect: confirm the groups match responsibilities you can name before splitting.
Low cohesion: WorkStealingThreadPool (LCOM4 6) core/jvm-native/src/main/scala/cats/effect/unsafe/WorkStealingThreadPool.scala:67 — WorkStealingThreadPool's methods fall into 6 groups that share no field and call none of each other, against a bar of more than 3 for this run (LCOM4, configurable — your repository's bar is the one quoted here). Each group is a set of methods reachable from one another through shared fields or direct calls, so 6 groups means the type has that many internally-connected clusters with nothing tying them together. Types whose shape makes a high count expected — and which would otherwise dominate this list — are excluded before this row is raised, so this is a genuine split candidate rather than a metric reading. It is still a shape, not a defect: confirm the groups match responsibilities you can name before splitting.
Low cohesion: WorkStealingBenchmark (LCOM4 5) benchmarks/src/main/scala/cats/effect/benchmarks/WorkStealingBenchmark.scala:46 — WorkStealingBenchmark's methods fall into 5 groups that share no field and call none of each other, against a bar of more than 3 for this run (LCOM4, configurable — your repository's bar is the one quoted here). Each group is a set of methods reachable from one another through shared fields or direct calls, so 5 groups means the type has that many internally-connected clusters with nothing tying them together. Types whose shape makes a high count expected — and which would otherwise dominate this list — are excluded before this row is raised, so this is a genuine split candidate rather than a metric reading. It is still a shape, not a defect: confirm the groups match responsibilities you can name before splitting.
Low cohesion: CallbackStack (LCOM4 4) core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:26 — CallbackStack's methods fall into 4 groups that share no field and call none of each other, against a bar of more than 3 for this run (LCOM4, configurable — your repository's bar is the one quoted here). Each group is a set of methods reachable from one another through shared fields or direct calls, so 4 groups means the type has that many internally-connected clusters with nothing tying them together. Types whose shape makes a high count expected — and which would otherwise dominate this list — are excluded before this row is raised, so this is a genuine split candidate rather than a metric reading. It is still a shape, not a defect: confirm the groups match responsibilities you can name before splitting.

D4 · Code Duplication · Duplicated block (9 lines × 2) · ×3

Duplicated block (9 lines × 2) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:244 — core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:244-252 | core/native/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:80-88 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere both call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made twice. Each matched range is the entire body of the declaration above it, so the region is already a complete unit: move that whole declaration to the shared location and have each site call it, rather than lifting the lines out of their bodies. Any `return` inside it is the body's own exit and keeps its meaning in the moved unit. ★ These copies have DRIFTED, and that is worth reading before extracting anything: just after the matched lines, `core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:254` calls `createDefaultScheduler`, `createDefaultPollingSystem`, `SelectorSystem` and `core/native/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:90` does not — after which the two agree again for 2 more lines. One of those two behaviours is the intended one and the other is what a copy-paste left behind, so decide which BEFORE unifying them: extracting the shared part will silently settle it, and if the copy that skips the call is the wrong one, that bug is already live.
Duplicated block (9 lines × 2) std/shared/src/main/scala/cats/effect/std/Dequeue.scala:170 — std/shared/src/main/scala/cats/effect/std/Dequeue.scala:170-178 | std/shared/src/main/scala/cats/effect/std/PQueue.scala:90-98 — the copies sit in sibling files of one directory, so a shared home is within easy reach: extract the block into a single shared function the call sites can all reach — a file they already depend on, or a new one alongside them — and call it from both call sites, so a change lands once. Read the line range as the matched WINDOW rather than a finished unit: at `std/shared/src/main/scala/cats/effect/std/Dequeue.scala:170` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (9 lines × 2) std/shared/src/main/scala/cats/effect/std/Dequeue.scala:369 — std/shared/src/main/scala/cats/effect/std/Dequeue.scala:369-377 | std/shared/src/main/scala/cats/effect/std/QueueSource.scala:70-78 — the copies sit in sibling files of one directory, so a shared home is within easy reach: extract the block into a single shared function the call sites can all reach — a file they already depend on, or a new one alongside them — and call it from both call sites, so a change lands once. Read the line range as the matched WINDOW rather than a finished unit: at `std/shared/src/main/scala/cats/effect/std/Dequeue.scala:369` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D2 · Cognitive Complexity · Node.packHead (cognitive 22) · ×2

Node.packHead (cognitive 22) core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:185 — Node.packHead has cognitive complexity 22 (threshold 15). Drivers by points: if/else 13 (21 pts), boolean chains 1 (nesting depth added 8). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.
Node.packHead (cognitive 22) core/shared/src/main/scala/cats/effect/unsafe/WeakList.scala:116 — Node.packHead has cognitive complexity 22 (threshold 15). Drivers by points: if/else 13 (21 pts), boolean chains 1 (nesting depth added 8). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D36 · Supply-chain Provenance & Signing REDACTED · ×2

REDACTED
REDACTED

D4 · Code Duplication · Duplicated block (20 lines × 2) · ×2

Duplicated block (20 lines × 2) core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:233 — core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:233-252 | core/shared/src/main/scala/cats/effect/unsafe/WeakList.scala:164-183 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere both call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made twice. Read the line range as the matched WINDOW rather than a finished unit: at `core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:233` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (20 lines × 2) core/jvm/src/main/scala/cats/effect/IOApp.scala:491 — core/jvm/src/main/scala/cats/effect/IOApp.scala:491-510 | core/native/src/main/scala/cats/effect/IOApp.scala:382-401 — before extracting anything, compare `core/jvm/src/main/scala/cats/effect/IOApp.scala` and `core/native/src/main/scala/cats/effect/IOApp.scala` as WHOLE FILES: this scan already matched 3 separate duplicated blocks between them, totalling at least 70 lines, which is the signature of one file having been copied from the other rather than of a helper waiting to be extracted. The two sit in different directories, so one cannot simply be deleted in favour of the other while both are reached separately: hoist the shared part into a location both already depend on and have each file call it, and retire whichever file turns out to have no caller of its own left. Extracting one helper per block leaves the fork in place. Read the line range as the matched WINDOW rather than a finished unit: at `core/native/src/main/scala/cats/effect/IOApp.scala:382` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D4 · Code Duplication · Duplicated block (19 lines × 2) · ×2

Duplicated block (19 lines × 2) core/shared/src/main/scala/cats/effect/IOFiber.scala:336 — core/shared/src/main/scala/cats/effect/IOFiber.scala:336-354 | core/shared/src/main/scala/cats/effect/IOFiber.scala:407-425 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `core/shared/src/main/scala/cats/effect/IOFiber.scala:336` it does not close everything it opens, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (19 lines × 2) core/shared/src/main/scala/cats/effect/unsafe/ThreadSafeHashtable.scala:46 — core/shared/src/main/scala/cats/effect/unsafe/ThreadSafeHashtable.scala:46-64 | core/shared/src/main/scala/cats/effect/unsafe/ThreadSafeHashtable.scala:112-130 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `core/shared/src/main/scala/cats/effect/unsafe/ThreadSafeHashtable.scala:46` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D4 · Code Duplication · Duplicated block (14 lines × 2) · ×2

Duplicated block (14 lines × 2) core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:384 — core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:384-397 | core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:891-904 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:384` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (14 lines × 2) core/shared/src/main/scala/cats/effect/IOFiber.scala:370 — core/shared/src/main/scala/cats/effect/IOFiber.scala:370-383 | core/shared/src/main/scala/cats/effect/IOFiber.scala:439-452 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `core/shared/src/main/scala/cats/effect/IOFiber.scala:370` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that. ★ These copies have DRIFTED, and that is worth reading before extracting anything: just before the matched lines, `core/shared/src/main/scala/cats/effect/IOFiber.scala:367` calls `succeeded`, `failed` and `core/shared/src/main/scala/cats/effect/IOFiber.scala:435` does not — after which the two agree again for 3 more lines. One of those two behaviours is the intended one and the other is what a copy-paste left behind, so decide which BEFORE unifying them: extracting the shared part will silently settle it, and if the copy that skips the call is the wrong one, that bug is already live.

D4 · Code Duplication · Duplicated block (11 lines × 2) · ×2

Duplicated block (11 lines × 2) core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala:307 — core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala:307-317 | core/native/src/main/scala/cats/effect/unsafe/KqueueSystem.scala:307-317 — the copies sit in sibling files of one directory, so a shared home is within easy reach: extract the block into a single shared function the call sites can all reach — a file they already depend on, or a new one alongside them — and call it from both call sites, so a change lands once. Read the line range as the matched WINDOW rather than a finished unit: at `core/native/src/main/scala/cats/effect/unsafe/EpollSystem.scala:307` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (11 lines × 2) std/shared/src/main/scala/cats/effect/std/Dequeue.scala:91 — std/shared/src/main/scala/cats/effect/std/Dequeue.scala:91-101 | std/shared/src/main/scala/cats/effect/std/Dequeue.scala:392-402 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited.

D4 · Code Duplication · Duplicated block (8 lines × 2) · ×2

Duplicated block (8 lines × 2) core/shared/src/main/scala/cats/effect/IO.scala:1358 — core/shared/src/main/scala/cats/effect/IO.scala:1358-1365 | kernel/shared/src/main/scala/cats/effect/kernel/Async.scala:96-103 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere both call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made twice. Read the line range as the matched WINDOW rather than a finished unit: at `core/shared/src/main/scala/cats/effect/IO.scala:1358` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.
Duplicated block (8 lines × 2) std/shared/src/main/scala/cats/effect/std/Dequeue.scala:167 — std/shared/src/main/scala/cats/effect/std/Dequeue.scala:167-174 | std/shared/src/main/scala/cats/effect/std/Queue.scala:524-531 — the copies sit in sibling files of one directory, so a shared home is within easy reach: extract the block into a single shared function the call sites can all reach — a file they already depend on, or a new one alongside them — and call it from both call sites, so a change lands once. Read the line range as the matched WINDOW rather than a finished unit: at `std/shared/src/main/scala/cats/effect/std/Dequeue.scala:167` it does not close everything it opens, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

PF3 · Async & latency hygiene · Sync-over-async blocking · ×2

Sync-over-async blocking core/js/src/main/scala/cats/effect/IOPlatform.scala:61 — `unsafeRunSyncToFuture` is async and calls unsafeRunSync — a blocking call inside async code stalls the execution-context thread, and every future or fiber scheduled on it for as long as it runs.
Sync-over-async blocking core/js/src/main/scala/cats/effect/syntax/DispatcherSyntax.scala:45 — `unsafeRunSyncToFuture` is async and calls unsafeRunSync — a blocking call inside async code stalls the execution-context thread, and every future or fiber scheduled on it for as long as it runs.

D1 · Cyclomatic Complexity · IOFiber.runLoop (cyclomatic 126) · ×1

IOFiber.runLoop (cyclomatic 126) core/shared/src/main/scala/cats/effect/IOFiber.scala:210 — IOFiber.runLoop has cyclomatic complexity 126 (threshold 15). To reduce it, separate the cases: extract each independent branch into its own named function, and where the body has guards that only reject input, fold those into early returns at the top.

D1 · Cyclomatic Complexity · WorkerThread.run (cyclomatic 94) · ×1

WorkerThread.run (cyclomatic 94) core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:312 — WorkerThread.run has cyclomatic complexity 94 (threshold 15). To reduce it, separate the cases: extract each independent branch into its own named function, and where the body has guards that only reject input, fold those into early returns at the top.

D1 · Cyclomatic Complexity · IOApp.main (cyclomatic 29) · ×1

IOApp.main (cyclomatic 29) core/jvm/src/main/scala/cats/effect/IOApp.scala:406 — IOApp.main has cyclomatic complexity 29 (threshold 15). To reduce it, separate the cases: extract each independent branch into its own named function, and where the body has guards that only reject input, fold those into early returns at the top.

D1 · Cyclomatic Complexity · SyncIO.unsafeRunSync (cyclomatic 29) · ×1

SyncIO.unsafeRunSync (cyclomatic 29) core/shared/src/main/scala/cats/effect/SyncIO.scala:226 — SyncIO.unsafeRunSync has cyclomatic complexity 29 (threshold 15). To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Where every arm is uniform — the same kind of value, with no behaviour of its own — a table keyed by the case is the shorter form; wherever the arms carry different data or different behaviour, keep them as cases, because collapsing those trades an explicit, reviewable set of cases for nothing.

D1 · Cyclomatic Complexity · IOFiberPlatform.interruptibleImpl (cyclomatic 24) · ×1

IOFiberPlatform.interruptibleImpl (cyclomatic 24) core/jvm-native/src/main/scala/cats/effect/IOFiberPlatform.scala:27 — IOFiberPlatform.interruptibleImpl has cyclomatic complexity 24 (threshold 15). To reduce it, separate the cases: extract each independent branch into its own named function, and where the body has guards that only reject input, fold those into early returns at the top.

D1 · Cyclomatic Complexity · IOApp.main (cyclomatic 23) · ×1

IOApp.main (cyclomatic 23) core/native/src/main/scala/cats/effect/IOApp.scala:289 — IOApp.main has cyclomatic complexity 23 (threshold 15). To reduce it, split the body: these branches sit side by side rather than nested inside one another, so extracting each one on its own would leave a function per branch. Group the statements between the checks into named steps and move each step into its own function, so the body reads as a short sequence of named stages.

D1 · Cyclomatic Complexity · SyncStep.interpret (cyclomatic 22) · ×1

SyncStep.interpret (cyclomatic 22) core/shared/src/main/scala/cats/effect/IO.scala:2348 — SyncStep.interpret has cyclomatic complexity 22 (threshold 15). To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Where every arm is uniform — the same kind of value, with no behaviour of its own — a table keyed by the case is the shorter form; wherever the arms carry different data or different behaviour, keep them as cases, because collapsing those trades an explicit, reviewable set of cases for nothing.

D1 · Cyclomatic Complexity · Executor.sequential (cyclomatic 21) · ×1

Executor.sequential (cyclomatic 21) std/shared/src/main/scala/cats/effect/std/Dispatcher.scala:509 — Executor.sequential has cyclomatic complexity 21 (threshold 15). To reduce it, break up the iteration: give each loop body a named function, and split a multi-phase loop into one function per phase so no single body carries the whole pipeline.

D1 · Cyclomatic Complexity · impl.semaphore (cyclomatic 21) · ×1

impl.semaphore (cyclomatic 21) std/shared/src/main/scala/cats/effect/std/Semaphore.scala:166 — impl.semaphore has cyclomatic complexity 21 (threshold 15). To reduce it, separate the cases: extract each independent branch into its own named function, and where the body has guards that only reject input, fold those into early returns at the top.

D1 · Cyclomatic Complexity · IOFiber.succeeded (cyclomatic 18) · ×1

IOFiber.succeeded (cyclomatic 18) core/shared/src/main/scala/cats/effect/IOFiber.scala:1209 — IOFiber.succeeded has cyclomatic complexity 18 (threshold 15). To reduce it, separate the branches: extract each independent case into its own named function so the top-level body reads as a short sequence of named decisions.

D1 · Cyclomatic Complexity · SupervisorImpl.supervise (cyclomatic 18) · ×1

SupervisorImpl.supervise (cyclomatic 18) std/shared/src/main/scala/cats/effect/std/Supervisor.scala:184 — SupervisorImpl.supervise has cyclomatic complexity 18 (threshold 15). To reduce it, break up the iteration: give each loop body a named function, and split a multi-phase loop into one function per phase so no single body carries the whole pipeline.

D1 · Cyclomatic Complexity · TestStdIn.default (cyclomatic 18) · ×1

TestStdIn.default (cyclomatic 18) testkit/shared/src/main/scala/cats/effect/testkit/TestConsole.scala:281 — TestStdIn.default has cyclomatic complexity 18 (threshold 15). To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Where every arm is uniform — the same kind of value, with no behaviour of its own — a table keyed by the case is the shorter form; wherever the arms carry different data or different behaviour, keep them as cases, because collapsing those trades an explicit, reviewable set of cases for nothing.

D1 · Cyclomatic Complexity · v3_0_0.fix (cyclomatic 18) · ×1

v3_0_0.fix (cyclomatic 18) scalafix/rules/src/main/scala/fix/v3_0_0.scala:9 — v3_0_0.fix has cyclomatic complexity 18 (threshold 15). To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Where every arm is uniform — the same kind of value, with no behaviour of its own — a table keyed by the case is the shorter form; wherever the arms carry different data or different behaviour, keep them as cases, because collapsing those trades an explicit, reviewable set of cases for nothing.

D1 · Cyclomatic Complexity · GenConcurrent.parTraverseN (cyclomatic 16) · ×1

GenConcurrent.parTraverseN (cyclomatic 16) kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala:145 — GenConcurrent.parTraverseN has cyclomatic complexity 16 (threshold 15). To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Where every arm is uniform — the same kind of value, with no behaviour of its own — a table keyed by the case is the shorter form; wherever the arms carry different data or different behaviour, keep them as cases, because collapsing those trades an explicit, reviewable set of cases for nothing.

D15 · Churn × Complexity Hotspots · Hotspot · ×1

Hotspot: kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala:145 — kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala changed 8 times in last 90 days, and the most complex body those changes touched has cyclomatic complexity 16 in GenConcurrent.parTraverseN at line 145. 1 of those changes was a fix/bug commit, and the other 7 changed it for other reasons — this file is under both repair and feature pressure. Before the next change lands here, make sure the area it touches is under test, then split that area out of the file so the following change is smaller than this one — a file this often edited pays the complexity back every time. Counted over 2026-06-30..2026-09-28, the 90 days ending at the analysed commit. Reproduce with `git log --since='2026-06-30 11:24:16 -05:00' --until='2026-09-28 11:24:16 -05:00' --full-history --no-merges -- kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala`: merges are excluded because a merge re-states changes already counted at their own commits, and history is NOT path-simplified because a change that reached the file through a merged branch is still a change to it. That command counts raw commits and can read HIGHER than this row, which counts a cherry-picked re-land, and a revert together with the commit it undoes, once each — a difference of several commits on a file whose history was re-landed or reverted inside the window.

D17 · Explicit Debt · HackComment · ×1

HackComment kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala:64 — // hack around functor law breakage — a workaround marked in source: record what it is compensating for and what would allow its removal (the upstream fix, the API it is waiting on, the invariant it restores), so the next reader can judge whether it is still needed rather than rediscovering why it is there.

D2 · Cognitive Complexity · IOFiber.runLoop (cognitive 316) · ×1

IOFiber.runLoop (cognitive 316) core/shared/src/main/scala/cats/effect/IOFiber.scala:210 — IOFiber.runLoop has cognitive complexity 316 (threshold 15). Drivers by points: if/else 75 (197 pts), error handling 20 (76 pts), match/switch 6 (22 pts), loops 4 (18 pts), boolean chains 3 (nesting depth added 208). To reduce it, flatten the nesting: this score is depth rather than breadth — most of its points come from checks stacked inside one another, so the work sits several levels in. Invert each enclosing check into an early exit (a return, or the language's equivalent) so the happy path stays at one level, and where a level cannot be exited early, lift the block it encloses into its own named function.

D2 · Cognitive Complexity · WorkerThread.run (cognitive 284) · ×1

WorkerThread.run (cognitive 284) core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:312 — WorkerThread.run has cognitive complexity 284 (threshold 15). Drivers by points: if/else 94 (190 pts), error handling 19 (67 pts), loops 6 (19 pts), boolean chains 8 (nesting depth added 157). To reduce it, flatten the nesting: this score is depth rather than breadth — most of its points come from checks stacked inside one another, so the work sits several levels in. Invert each enclosing check into an early exit (a return, or the language's equivalent) so the happy path stays at one level, and where a level cannot be exited early, lift the block it encloses into its own named function.

D2 · Cognitive Complexity · IOFiberPlatform.interruptibleImpl (cognitive 112) · ×1

IOFiberPlatform.interruptibleImpl (cognitive 112) core/jvm-native/src/main/scala/cats/effect/IOFiberPlatform.scala:27 — IOFiberPlatform.interruptibleImpl has cognitive complexity 112 (threshold 15). Drivers by points: if/else 16 (66 pts), loops 7 (29 pts), error handling 3 (15 pts), boolean chains 2 (nesting depth added 84). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · Executor.sequential (cognitive 71) · ×1

Executor.sequential (cognitive 71) std/shared/src/main/scala/cats/effect/std/Dispatcher.scala:509 — Executor.sequential has cognitive complexity 71 (threshold 15). Drivers by points: loops 10 (60 pts), match/switch 5 (10 pts), if/else 1 (nesting depth added 55). The drivers above price the dispatch low by construction — a dispatch is charged once however many cases it lists, while each branch inside an arm is charged in full — so most of this count is what the case bodies hold, and the arms are where it can be reduced. To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Keep every case explicit, and make the behaviour for cases you do not list a deliberate choice rather than an accident.

D2 · Cognitive Complexity · SupervisorImpl.supervise (cognitive 68) · ×1

SupervisorImpl.supervise (cognitive 68) std/shared/src/main/scala/cats/effect/std/Supervisor.scala:184 — SupervisorImpl.supervise has cognitive complexity 68 (threshold 15). Drivers by points: loops 8 (36 pts), if/else 9 (21 pts), match/switch 4 (10 pts), boolean chains 1 (nesting depth added 46). To reduce it, break up the iteration: give each loop body a named function, and split a multi-phase loop into one function per phase so no single body carries the whole pipeline.

D2 · Cognitive Complexity · RandomCommon.nextLongBounded (cognitive 66) · ×1

RandomCommon.nextLongBounded (cognitive 66) std/shared/src/main/scala/cats/effect/std/Random.scala:419 — RandomCommon.nextLongBounded has cognitive complexity 66 (threshold 15). Drivers by points: loops 11 (51 pts), if/else 4 (15 pts) (nesting depth added 51). To reduce it, break up the iteration: give each loop body a named function, and split a multi-phase loop into one function per phase so no single body carries the whole pipeline.

D2 · Cognitive Complexity · IOApp.main (cognitive 53) · ×1

IOApp.main (cognitive 53) core/jvm/src/main/scala/cats/effect/IOApp.scala:406 — IOApp.main has cognitive complexity 53 (threshold 15). Drivers by points: if/else 26 (41 pts), error handling 4 (8 pts), match/switch 1 (2 pts), boolean chains 1, loops 1 (nesting depth added 20). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · impl.semaphore (cognitive 52) · ×1

impl.semaphore (cognitive 52) std/shared/src/main/scala/cats/effect/std/Semaphore.scala:166 — impl.semaphore has cognitive complexity 52 (threshold 15). Drivers by points: if/else 25 (39 pts), match/switch 6 (12 pts), boolean chains 1 (nesting depth added 20). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · GenConcurrent.racePair (cognitive 42) · ×1

GenConcurrent.racePair (cognitive 42) kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala:339 — GenConcurrent.racePair has cognitive complexity 42 (threshold 15). Drivers by points: loops 9 (37 pts), match/switch 1 (5 pts) (nesting depth added 32). To reduce it, break up the iteration: give each loop body a named function, and split a multi-phase loop into one function per phase so no single body carries the whole pipeline.

D2 · Cognitive Complexity · LocalQueue.stealInto (cognitive 36) · ×1

LocalQueue.stealInto (cognitive 36) core/jvm-native/src/main/scala/cats/effect/unsafe/LocalQueue.scala:487 — LocalQueue.stealInto has cognitive complexity 36 (threshold 15). Drivers by points: if/else 10 (29 pts), loops 3 (7 pts) (nesting depth added 23). To reduce it, flatten the nesting: this score is depth rather than breadth — most of its points come from checks stacked inside one another, so the work sits several levels in. Invert each enclosing check into an early exit (a return, or the language's equivalent) so the happy path stays at one level, and where a level cannot be exited early, lift the block it encloses into its own named function.

D2 · Cognitive Complexity · IORuntimeCompanionPlatform.createWorkStealingComputeThreadPool (cognitive 34) · ×1

IORuntimeCompanionPlatform.createWorkStealingComputeThreadPool (cognitive 34) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:76 — IORuntimeCompanionPlatform.createWorkStealingComputeThreadPool has cognitive complexity 34 (threshold 15). Drivers by points: error handling 7 (22 pts), if/else 5 (8 pts), loops 1 (3 pts), boolean chains 1 (nesting depth added 20). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · IOApp.main (cognitive 34) · ×1

IOApp.main (cognitive 34) core/native/src/main/scala/cats/effect/IOApp.scala:289 — IOApp.main has cognitive complexity 34 (threshold 15). Drivers by points: if/else 15 (19 pts), error handling 2 (6 pts), match/switch 3 (6 pts), boolean chains 2, loops 1 (nesting depth added 11). To reduce it, split the body: most of this score is breadth rather than depth — checks laid out side by side rather than stacked — so group the statements between the checks into named steps and move each step into its own function. Some of it IS depth: where a check sits inside another whose only job is to reach it, merge the two into one condition, and where an else follows a branch that already returns, drop the trailing else and let the rest of the body continue at one level.

D2 · Cognitive Complexity · WorkStealingThreadPool.shutdown (cognitive 28) · ×1

WorkStealingThreadPool.shutdown (cognitive 28) core/jvm-native/src/main/scala/cats/effect/unsafe/WorkStealingThreadPool.scala:712 — WorkStealingThreadPool.shutdown has cognitive complexity 28 (threshold 15). Drivers by points: if/else 8 (16 pts), loops 4 (8 pts), boolean chains 2, match/switch 1 (2 pts) (nesting depth added 13). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · Worker.run (cognitive 25) · ×1

Worker.run (cognitive 25) std/shared/src/main/scala/cats/effect/std/Dispatcher.scala:411 — Worker.run has cognitive complexity 25 (threshold 15). Drivers by points: match/switch 4 (13 pts), if/else 6 (12 pts) (nesting depth added 15). To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Keep every case explicit, and make the behaviour for cases you do not list a deliberate choice rather than an accident.

D2 · Cognitive Complexity · UnsafeBounded.drain (cognitive 25) · ×1

UnsafeBounded.drain (cognitive 25) std/shared/src/main/scala/cats/effect/std/Queue.scala:1116 — UnsafeBounded.drain has cognitive complexity 25 (threshold 15). Drivers by points: if/else 8 (15 pts), loops 2 (7 pts), error handling 1 (2 pts), boolean chains 1 (nesting depth added 13). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · LocalQueue.enqueue (cognitive 24) · ×1

LocalQueue.enqueue (cognitive 24) core/jvm-native/src/main/scala/cats/effect/unsafe/LocalQueue.scala:196 — LocalQueue.enqueue has cognitive complexity 24 (threshold 15). Drivers by points: if/else 6 (16 pts), loops 3 (8 pts) (nesting depth added 15). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · SelectorSystem.processReadyEvents (cognitive 22) · ×1

SelectorSystem.processReadyEvents (cognitive 22) core/jvm/src/main/scala/cats/effect/unsafe/SelectorSystem.scala:57 — SelectorSystem.processReadyEvents has cognitive complexity 22 (threshold 15). Drivers by points: if/else 7 (17 pts), loops 2 (3 pts), error handling 1 (2 pts) (nesting depth added 12). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · IOFiber.onFatalFailure (cognitive 22) · ×1

IOFiber.onFatalFailure (cognitive 22) core/shared/src/main/scala/cats/effect/IOFiber.scala:1597 — IOFiber.onFatalFailure has cognitive complexity 22 (threshold 15). Drivers by points: if/else 4 (11 pts), loops 3 (11 pts) (nesting depth added 15). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · GenSpawnGenerators.genRacePair (cognitive 22) · ×1

GenSpawnGenerators.genRacePair (cognitive 22) kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/Generators.scala:247 — GenSpawnGenerators.genRacePair has cognitive complexity 22 (threshold 15). Drivers by points: if/else 4 (12 pts), loops 3 (6 pts), match/switch 1 (4 pts) (nesting depth added 14). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · ConsoleCompanionCrossPlatform.readLineWithCharsetImpl (cognitive 22) · ×1

ConsoleCompanionCrossPlatform.readLineWithCharsetImpl (cognitive 22) std/shared/src/main/scala/cats/effect/std/ConsoleCrossPlatform.scala:210 — ConsoleCompanionCrossPlatform.readLineWithCharsetImpl has cognitive complexity 22 (threshold 15). Drivers by points: if/else 12 (20 pts), error handling 1 (2 pts) (nesting depth added 9). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · PartialLine.append (cognitive 22) · ×1

PartialLine.append (cognitive 22) testkit/shared/src/main/scala/cats/effect/testkit/TestConsole.scala:449 — PartialLine.append has cognitive complexity 22 (threshold 15). Drivers by points: if/else 9 (15 pts), match/switch 2 (7 pts) (nesting depth added 11). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · IOFiber.succeeded (cognitive 20) · ×1

IOFiber.succeeded (cognitive 20) core/shared/src/main/scala/cats/effect/IOFiber.scala:1209 — IOFiber.succeeded has cognitive complexity 20 (threshold 15). Drivers by points: if/else 6 (11 pts), error handling 4 (8 pts), match/switch 1 (nesting depth added 9). The drivers above price the dispatch low by construction — a dispatch is charged once however many cases it lists, while each branch inside an arm is charged in full — so most of this count is what the case bodies hold, and the arms are where it can be reduced. To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Keep every case explicit, and make the behaviour for cases you do not list a deliberate choice rather than an accident.

D2 · Cognitive Complexity · TimerHeap.pollFirstIfTriggered (cognitive 19) · ×1

TimerHeap.pollFirstIfTriggered (cognitive 19) core/jvm-native/src/main/scala/cats/effect/unsafe/TimerHeap.scala:133 — TimerHeap.pollFirstIfTriggered has cognitive complexity 19 (threshold 15). Drivers by points: if/else 9 (16 pts), boolean chains 3 (nesting depth added 7). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · SyncIO.unsafeRunSync (cognitive 19) · ×1

SyncIO.unsafeRunSync (cognitive 19) core/shared/src/main/scala/cats/effect/SyncIO.scala:226 — SyncIO.unsafeRunSync has cognitive complexity 19 (threshold 15). Drivers by points: if/else 8 (11 pts), error handling 4 (5 pts), match/switch 3 (nesting depth added 4). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · ThreadSafeHashtable.remove (cognitive 19) · ×1

ThreadSafeHashtable.remove (cognitive 19) core/shared/src/main/scala/cats/effect/unsafe/ThreadSafeHashtable.scala:92 — ThreadSafeHashtable.remove has cognitive complexity 19 (threshold 15). Drivers by points: if/else 5 (12 pts), loops 2 (5 pts), boolean chains 2 (nesting depth added 10). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · SyncStep.interpret (cognitive 18) · ×1

SyncStep.interpret (cognitive 18) core/shared/src/main/scala/cats/effect/IO.scala:2348 — SyncStep.interpret has cognitive complexity 18 (threshold 15). Drivers by points: match/switch 5 (14 pts), if/else 4 (nesting depth added 9). To reduce it, keep the dispatch but shrink the arms: move each non-trivial case body into its own named function (or onto the value being matched) so the dispatch reads one line per case, and group related cases into a sub-dispatch. Keep every case explicit, and make the behaviour for cases you do not list a deliberate choice rather than an accident.

D2 · Cognitive Complexity · Dispatcher.impl (cognitive 18) · ×1

Dispatcher.impl (cognitive 18) std/shared/src/main/scala/cats/effect/std/Dispatcher.scala:246 — Dispatcher.impl has cognitive complexity 18 (threshold 15). Drivers by points: if/else 13 (15 pts), match/switch 2 (3 pts) (nesting depth added 3). To reduce it, split the body: this score is breadth rather than depth — many checks laid out side by side rather than nested inside one another, so inverting conditions into early returns has nothing left to flatten. Group the statements between the checks into named steps and move each step into its own function, so the body reads as a short sequence of named stages.

D2 · Cognitive Complexity · HandleRef.tryModify (cognitive 18) · ×1

HandleRef.tryModify (cognitive 18) std/shared/src/main/scala/cats/effect/std/MapRef.scala:228 — HandleRef.tryModify has cognitive complexity 18 (threshold 15). Drivers by points: if/else 8 (14 pts), match/switch 2 (4 pts) (nesting depth added 8). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D2 · Cognitive Complexity · Poller.poll (cognitive 16) · ×1

Poller.poll (cognitive 16) core/native/src/main/scala/cats/effect/unsafe/KqueueSystem.scala:271 — Poller.poll has cognitive complexity 16 (threshold 15). Drivers by points: if/else 13 (16 pts) (nesting depth added 3). To reduce it, split the body: most of this score is breadth rather than depth — checks laid out side by side rather than stacked — so group the statements between the checks into named steps and move each step into its own function. Some of it IS depth: where a check sits inside another whose only job is to reach it, merge the two into one condition, and where an else follows a branch that already returns, drop the trailing else and let the rest of the body continue at one level.

D2 · Cognitive Complexity · UnsafeUnbounded.take (cognitive 16) · ×1

UnsafeUnbounded.take (cognitive 16) std/shared/src/main/scala/cats/effect/std/UnsafeUnbounded.scala:51 — UnsafeUnbounded.take has cognitive complexity 16 (threshold 15). Drivers by points: if/else 7 (11 pts), loops 1 (4 pts), boolean chains 1 (nesting depth added 7). To reduce it, split the body into named stages: move each independent step or branch into its own named function so the body reads as a short sequence of named calls rather than one long body.

D29 · Static Analysis (SAST) · REDACTED · ×1

REDACTED

D29 · Static Analysis (SAST) · REDACTED · ×1

REDACTED

D35 · Change Coupling · Change coupling · ×1

Change coupling: IO.scala ↔ GenConcurrentSyntax.scala core/shared/src/main/scala/cats/effect/IO.scala:1 — `core/shared/src/main/scala/cats/effect/IO.scala` and `kernel/shared/src/main/scala/cats/effect/kernel/syntax/GenConcurrentSyntax.scala` change together 55% of the time (6 of the 11 commits that touched whichever of the two files changed less often, counting a file under its earlier names as well — a repo-wide or module-wide sweep is evidence about the sweep rather than about any pair inside it and is left out of BOTH sides of this ratio, while a dependency bump, a formatter/rename sweep, or a commit whose edit to one of the two files was a tool directive such as //go:generate or whitespace only is left out of the shared count ONLY, so the two sides are not taken over identical commit sets) with no explicit dependency — the edge is real but nothing declares it. Read the pair before acting: if one registers itself into the other through a hook or an initialiser, the missing dependency is DELIBERATE — the registration is the link, and it is meant not to be an import — and the thing to add is a comment on each side naming the other, not a merge; if they simply belong together, co-locate them; if neither holds, the coupling is hidden and worth breaking. You can check this without leaving the row: of the 6 shared commits counted here, the most recent 3 are `7eca63a6` Add `GenConcurrent#parSequenceN_` and `GenConcurrent#parTraverseN_`.; `690c1697` Introduce parReplicateAN; `aafb6bab` Override parSequenceN for IO, based on Monix queue implementation — run `git show` on any of them.

D36 · Supply-chain Provenance & Signing · REDACTED · ×1

REDACTED

D36 · Supply-chain Provenance & Signing · REDACTED · ×1

REDACTED

D4 · Code Duplication · Members sharing a duplicated core (4 members, 50+ identical tokens) · ×1

Members sharing a duplicated core (4 members, 50+ identical tokens) std/shared/src/main/scala/cats/effect/std/PQueue.scala:194 — std/shared/src/main/scala/cats/effect/std/PQueue.scala:194-208 | std/shared/src/main/scala/cats/effect/std/Queue.scala:1191-1205 | std/shared/src/main/scala/cats/effect/std/unsafe/BoundedQueue.scala:42-56 | std/shared/src/main/scala/cats/effect/std/unsafe/UnboundedQueue.scala:42-56 — These 4 members share a duplicated core: a run of at least 50 identical tokens appears in every one of them. That run is NOT broken out as duplicated-block rows below — it is what admitted this row, and the blocks below cover only the part of it that clears the block floor, so they understate the correspondence. Read the members as one construct written 4 times. The repair is at the members' grain — factor the shared implementation out once and have all of them call it with their differences as parameters or as an injected step, or, where the difference is systematic, generate them from one template. Extracting the individual blocks below is not the same fix: it leaves every body in place and the next edit still has to be made 4 times.

D4 · Code Duplication · Duplicated block (51 lines × 2) · ×1

Duplicated block (51 lines × 2) core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:430 — core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:430-480 | core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:534-584 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:430` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D4 · Code Duplication · Duplicated block (35 lines × 2) · ×1

Duplicated block (35 lines × 2) core/jvm/src/main/scala/cats/effect/IOApp.scala:421 — core/jvm/src/main/scala/cats/effect/IOApp.scala:421-455 | core/native/src/main/scala/cats/effect/IOApp.scala:300-334 — before extracting anything, compare `core/jvm/src/main/scala/cats/effect/IOApp.scala` and `core/native/src/main/scala/cats/effect/IOApp.scala` as WHOLE FILES: this scan already matched 3 separate duplicated blocks between them, totalling at least 70 lines, which is the signature of one file having been copied from the other rather than of a helper waiting to be extracted. The two sit in different directories, so one cannot simply be deleted in favour of the other while both are reached separately: hoist the shared part into a location both already depend on and have each file call it, and retire whichever file turns out to have no caller of its own left. Extracting one helper per block leaves the fork in place. Read the line range as the matched WINDOW rather than a finished unit: at `core/native/src/main/scala/cats/effect/IOApp.scala:300` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D4 · Code Duplication · Duplicated block (31 lines × 2) · ×1

Duplicated block (31 lines × 2) core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:190 — core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:190-220 | core/shared/src/main/scala/cats/effect/unsafe/WeakList.scala:121-151 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere both call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made twice. Read the line range as the matched WINDOW rather than a finished unit: at `core/jvm-native/src/main/scala/cats/effect/CallbackStack.scala:190` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D4 · Code Duplication · Duplicated block (19–20 lines × 2) · ×1

Duplicated block (19–20 lines × 2) core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:372 — core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:372-390 | core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:495-514 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited. Read the line range as the matched WINDOW rather than a finished unit: at `core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala:372` it begins part-way through the construct above it, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D4 · Code Duplication · Duplicated block (17 lines × 2) · ×1

Duplicated block (17 lines × 2) core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:276 — core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:276-292 | core/native/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:105-121 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere both call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made twice. Each matched range is the entire body of the declaration above it, so the region is already a complete unit: move that whole declaration to the shared location and have each site call it, rather than lifting the lines out of their bodies. Any `return` inside it is the body's own exit and keeps its meaning in the moved unit.

D4 · Code Duplication · Duplicated block (15 lines × 2) · ×1

Duplicated block (15 lines × 2) core/jvm/src/main/scala/cats/effect/IOApp.scala:230 — core/jvm/src/main/scala/cats/effect/IOApp.scala:230-244 | core/native/src/main/scala/cats/effect/IOApp.scala:225-239 — before extracting anything, compare `core/jvm/src/main/scala/cats/effect/IOApp.scala` and `core/native/src/main/scala/cats/effect/IOApp.scala` as WHOLE FILES: this scan already matched 3 separate duplicated blocks between them, totalling at least 70 lines, which is the signature of one file having been copied from the other rather than of a helper waiting to be extracted. The two sit in different directories, so one cannot simply be deleted in favour of the other while both are reached separately: hoist the shared part into a location both already depend on and have each file call it, and retire whichever file turns out to have no caller of its own left. Extracting one helper per block leaves the fork in place. ★ These copies have DRIFTED, and that is worth reading before extracting anything: just after the matched lines, `core/jvm/src/main/scala/cats/effect/IOApp.scala:246` calls `UnsupportedOperationException` and `core/native/src/main/scala/cats/effect/IOApp.scala:263` does not — after which the two agree again for 2 more lines. One of those two behaviours is the intended one and the other is what a copy-paste left behind, so decide which BEFORE unifying them: extracting the shared part will silently settle it, and if the copy that skips the call is the wrong one, that bug is already live.

D4 · Code Duplication · Duplicated block (12 lines × 4) · ×1

Duplicated block (12 lines × 4) std/shared/src/main/scala/cats/effect/std/PQueue.scala:197 — std/shared/src/main/scala/cats/effect/std/PQueue.scala:197-208 | std/shared/src/main/scala/cats/effect/std/Queue.scala:1194-1205 | std/shared/src/main/scala/cats/effect/std/unsafe/BoundedQueue.scala:45-56 | std/shared/src/main/scala/cats/effect/std/unsafe/UnboundedQueue.scala:45-56 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere all 4 call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made 4 times. Read the line range as the matched WINDOW rather than a finished unit: at `std/shared/src/main/scala/cats/effect/std/PQueue.scala:197` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

D4 · Code Duplication · Duplicated block (12 lines × 2) · ×1

Duplicated block (12 lines × 2) core/shared/src/main/scala/cats/effect/IOFiber.scala:1020 — core/shared/src/main/scala/cats/effect/IOFiber.scala:1020-1031 | core/shared/src/main/scala/cats/effect/IOFiber.scala:1038-1049 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited.

D4 · Code Duplication · Duplicated block (10 lines × 2) · ×1

Duplicated block (10 lines × 2) kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/Generators.scala:294 — kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/Generators.scala:294-303 | kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/Generators.scala:322-331 — both copies are in the same file, so extract the block into one function there and call it from each site — the copies drift apart the first time only one of them is edited.

D4 · Code Duplication · Duplicated block (5 lines × 2) · ×1

Duplicated block (5 lines × 2) core/js/src/main/scala/cats/effect/ByteStack.scala:60 — core/js/src/main/scala/cats/effect/ByteStack.scala:60-64 | core/jvm-native/src/main/scala/cats/effect/ByteStack.scala:81-85 — the copies span different directories, so extracting a shared function means choosing where it lives: put it somewhere both call sites can already reach — a location they all depend on today, or a new shared one if there is none — and call it from each site; until then, every change has to be made twice.

D4 · Code Duplication · Duplicated block (5 lines × 3) · ×1

Duplicated block (5 lines × 3) kernel/shared/src/main/scala/cats/effect/kernel/GenSpawn.scala:636 — kernel/shared/src/main/scala/cats/effect/kernel/GenSpawn.scala:636-640 | kernel/shared/src/main/scala/cats/effect/kernel/GenSpawn.scala:696-700 | kernel/shared/src/main/scala/cats/effect/kernel/GenSpawn.scala:765-769 — all 3 copies are in the same file, so extract the block into one function there and call it from every one of those sites — resolving only two of them leaves the rest to drift apart the first time one is edited. Read the line range as the matched WINDOW rather than a finished unit: at `kernel/shared/src/main/scala/cats/effect/kernel/GenSpawn.scala:636` it runs out through the closing brace of the declaration holding it — the window is that declaration's tail, not a fragment that begins part-way through something, so those exact lines cannot be lifted as they stand — widen the region to the smallest complete statement or declaration that contains it, and extract that.

IC1 · Incompleteness & stubs · Hollow method · ×1

Hollow method — returns a constant without doing the work core/js-native/src/main/scala/cats/effect/IOFiberConstants.scala:52 — `isVirtualThread` looks like it should compute a result but its body just returns a constant — a placeholder return that was never filled in.

P2 · Observability · No structured logging · ×1

No structured logging — No logging or diagnostics emission found. This repository ships a binary its users launch rather than a service you operate, so there is no operator to page — but when a run fails on a user's machine, neither they nor you have anything to read.

Minor — 22 finding(s)

IC1 · Incompleteness & stubs · Disabled test · ×6

Disabled test ioapp-tests/src/test/scala/IOAppSuite.scala:249 — A test is skipped/ignored — coverage that looks present but never runs. Re-enable it or delete it so the green run means something.
Disabled test tests/jvm/src/test/scala/cats/effect/IOPlatformSuite.scala:104 — A test is skipped/ignored — coverage that looks present but never runs. Re-enable it or delete it so the green run means something.
Disabled test tests/jvm/src/test/scala/cats/effect/unsafe/WorkerThreadNameSuite.scala:57 — A test is skipped/ignored — coverage that looks present but never runs. Re-enable it or delete it so the green run means something.
Disabled test tests/shared/src/test/scala/cats/effect/IOFiberSuite.scala:55 — A test is skipped/ignored — coverage that looks present but never runs. Re-enable it or delete it so the green run means something.
Disabled test tests/shared/src/test/scala/cats/effect/IOFiberSuite.scala:59 — A test is skipped/ignored — coverage that looks present but never runs. Re-enable it or delete it so the green run means something.
Disabled test tests/shared/src/test/scala/cats/effect/tracing/TraceSuite.scala:49 — A test is skipped/ignored — coverage that looks present but never runs. Re-enable it or delete it so the green run means something.

AX6 · Interface segregation · Fat interface · ×2

Fat interface: PollerMetrics (25 abstract members) core/jvm-native/src/main/scala/cats/effect/unsafe/metrics/PollerMetrics.scala:19 — `PollerMetrics` declares 25 abstract members: `operationsOutstandingCount`, `totalOperationsSubmittedCount`, `totalOperationsSucceededCount`, `totalOperationsErroredCount`, `totalOperationsCanceledCount`, `acceptOperationsOutstandingCount`, `totalAcceptOperationsSubmittedCount`, `totalAcceptOperationsSucceededCount`, `totalAcceptOperationsErroredCount`, `totalAcceptOperationsCanceledCount`, `connectOperationsOutstandingCount`, `totalConnectOperationsSubmittedCount`, `totalConnectOperationsSucceededCount`, `totalConnectOperationsErroredCount`, `totalConnectOperationsCanceledCount`, `readOperationsOutstandingCount`, `totalReadOperationsSubmittedCount`, `totalReadOperationsSucceededCount`, `totalReadOperationsErroredCount`, `totalReadOperationsCanceledCount`, `writeOperationsOutstandingCount`, `totalWriteOperationsSubmittedCount`, `totalWriteOperationsSucceededCount`, `totalWriteOperationsErroredCount`, `totalWriteOperationsCanceledCount`. Counted over its ABSTRACT members — a `def` with no body or a `val`/`var` with no initializer, once per signature; concrete members, private and protected members, and members of a companion `object` are not counted, because no implementer is forced to write them. A wide interface forces every implementer and caller to depend on methods they don't use (the Interface-Segregation 'I' in SOLID). Split it into focused role-interfaces.
Fat interface: Random[F] (18 abstract members) std/shared/src/main/scala/cats/effect/std/Random.scala:42 — `Random[F]` declares 18 abstract members: `betweenDouble`, `betweenFloat`, `betweenInt`, `betweenLong`, `nextAlphaNumeric`, `nextBoolean`, `nextBytes`, `nextDouble`, `nextFloat`, `nextGaussian`, `nextInt`, `nextIntBounded`, `nextLong`, `nextLongBounded`, `nextPrintableChar`, `nextString`, `shuffleList`, `shuffleVector`. Counted over its ABSTRACT members — a `def` with no body or a `val`/`var` with no initializer, once per signature; concrete members, private and protected members, and members of a companion `object` are not counted, because no implementer is forced to write them. A wide interface forces every implementer and caller to depend on methods they don't use (the Interface-Segregation 'I' in SOLID). Split it into focused role-interfaces.

X10 · Duplicated predicate · Duplicated predicate · ×2

Duplicated predicate core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala:94 — `blockedThreadDetectionEnabled && (threads > 1)` appears character-identically in 2 files — core/jvm/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala, core/native/src/main/scala/cats/effect/unsafe/IORuntimeCompanionPlatform.scala. It is one line, so the duplication detector's token window never sees it; the copies drift when only one is corrected. Give the condition a name and one home.
Duplicated predicate core/js/src/main/scala/cats/effect/tracing/TracingConstants.scala:38 — `isFullStackTracing || isCachedStackTracing` appears character-identically in 2 files — core/js/src/main/scala/cats/effect/tracing/TracingConstants.scala, core/native/src/main/scala/cats/effect/tracing/TracingConstants.scala. It is one line, so the duplication detector's token window never sees it; the copies drift when only one is corrected. Give the condition a name and one home.

D16 · Bus Factor · Off-boarding risk · ×1

Off-boarding risk: anonymized user #1 — If anonymized user #1 becomes unavailable, 3 significant file(s) lose their only recent owner: std/shared/src/main/scala/cats/effect/std/AtomicCell.scala, std/shared/src/main/scala/cats/effect/std/AtomicMap.scala, std/shared/src/main/scala/cats/effect/std/KeyedMutex.scala. Pair on, review, or document these before any departure.

D16 · Bus Factor · Further sole-owners (lower concentration) · ×1

Further sole-owners (lower concentration) — 5 other contributor(s) are each the sole owner of a small amount of code below the off-boarding threshold — folded into the bus-factor score and metrics (11 single-owned of 131 analysed files in total, counted over production source files of roughly 2,400 bytes or more, excluding vendored, generated, example/demo and scaffolding-template trees and test files identified by path convention, largest first; 131 of the 322 production source files in this repository met that bar). They are anonymized user #2 (2 file(s)), anonymized user #3 (2 file(s)), anonymized user #4 (2 file(s)), anonymized user #5 (1 file(s)), anonymized user #6 (1 file(s)) — spread or document their files in the same way, at lower priority than the named off-boarding risks above. The files folded here: core/jvm-native/src/main/scala/cats/effect/unsafe/WorkerThread.scala, std/shared/src/main/scala/cats/effect/std/Supervisor.scala, kernel/shared/src/main/scala/cats/effect/kernel/GenConcurrent.scala, benchmarks/src/main/scala/cats/effect/benchmarks/ParallelBenchmark.scala, testkit/shared/src/main/scala/cats/effect/testkit/TestConsole.scala, std/shared/src/main/scala/cats/effect/std/NonEmptyHotswap.scala, kernel-testkit/shared/src/main/scala/cats/effect/kernel/testkit/TestContext.scala, kernel/shared/src/main/scala/cats/effect/kernel/instances/GenSpawnInstances.scala.

D20 · ADR Quality · No ADRs found · ×1

No ADRs found — No ADRs found. No recognised ADR directory (`docs/adr/`, `docs/decisions/`, `adr/`, `docs/rfcs/`, an `ADR0001/` folder, or their siblings) exists anywhere in this tree. What was searched, so you can tell an empty log from a search that missed one: every directory under the tree (build output, dependencies and VCS metadata excepted), for a document that is either any non-index page inside a recognised ADR directory, whatever its name and however deeply nested (`docs/adr/use-postgres.md`, `docs/adr/2024/0001-x.md`); or a file anywhere whose name is ADR-shaped (`0001-use-postgres.md`, `adr-012-caching.md`); or, when neither turned anything up, a document carrying the decision-record signature (an "Architecture Decision Record" heading, or Status / Context / Decision / Consequences as section headings). A decision log that clears none of these — unnumbered files outside any recognised directory, without those headings — is not seen by this check and this row is then wrong. If that is your case, say so rather than renaming anything; otherwise, consider recording architectural decisions in `docs/adr/`.

D26 · Project Cohesion · Projects may be oversized for their cohesion · ×1

Projects may be oversized for their cohesion — 1 of 2 project(s) overshoot their size bounds, lowering Project Cohesion to 0.0/10. The most over is `(repository root)` (38702 LoC, 467 module-visible types across 36 directories). Review these for cohesion — draw the boundary inside the module first (group each responsibility into its own package or directory and keep the cross-boundary members non-public), since splitting a published package moves types between packages and breaks consumers.

D36 · Supply-chain Provenance & Signing · REDACTED · ×1

REDACTED

D36 · Supply-chain Provenance & Signing · REDACTED · ×1

REDACTED

IC1 · Incompleteness & stubs · Method throws UnsupportedOperationException · ×1

Method throws UnsupportedOperationException std/js/src/main/scala/cats/effect/std/SecureRandomCompanionPlatform.scala:108 — `notSupported`'s body only throws UnsupportedOperationException — sometimes a deliberate refusal, often an unfinished stub. Confirm it's intentional.

M2 · Architecture documentation · No ADRs · ×1

No ADRs — No Architecture Decision Records found — no conventional ADR directory, no numbered `NNNN-title` documents in any markup this check reads, and nothing ADR-shaped by content. Design rationale recorded elsewhere (a design-notes tree, a mailing list, pull-request discussion) is not visible to this check and is not re-findable per decision, so a future maintainer cannot ask why one choice was made and get an answer.

M2 · Architecture documentation · No architecture diagram/doc · ×1

No architecture diagram/doc — No C4/Structurizr/PlantUML/Mermaid/Graphviz/D2 diagram, no drawn diagram named for the architecture, no file named `architecture` or `design` in any markup this check reads, and nothing in the README, docs or contributor guides that announces the shape — no `## Architecture` heading, no "architecture overview"/"high-level design" phrasing, no "the architecture is …" introduction, no guided code tour. A shape laid out in prose that never names itself as the architecture is not visible to this check, and neither is one kept outside the repository, so this row reports the absence of a re-findable shape document — not evidence that nobody wrote the shape down.

P6 · Release Hygiene · No changelog · ×1

No changelog — No CHANGELOG/HISTORY/RELEASES file — what shipped when isn't easy to reconstruct for support or audit. (Versioning/tagging makes releases traceable, but a changelog records the what.)

PF1 · Benchmark discipline · Benchmarks don't track allocations · ×1

Benchmarks don't track allocations benchmarks/src/main/scala/cats/effect/benchmarks/ArrayStackBenchmark.scala — A JMH/Jetpack Benchmark suite exists but nothing turns on its allocation measurement — allocations (the main way hot code pressures a garbage collector or allocator) aren't being measured.

X5 · Nullable reference types · Scala's null is not held to the type system everywhere · ×1

Scala's null is not held to the type system everywhere — No build over this repository's 280 Scala product file(s) passes `-Yexplicit-nulls`, enables WartRemover's `Null` wart or runs Scalafix's `DisableSyntax.noNulls`, so every reference type admits null and nothing reports a `null` written into the code or returned from a Java API — the first one to reach a method call is a `NullPointerException`. `Option` by convention is a habit no tool here holds the code to.

Minor — 1 finding(s)

D12 · Dependency Hygiene · Dependency hygiene PARTLY measured · ×1

Dependency hygiene PARTLY measured — npm pinning read, dependency currency not (the committed lockfile resolved no direct production dependency) — This repository's npm dependencies were read for PINNING discipline: 0 production declaration(s) plus 1 development one(s) across 1 package.json (1 of them the product — the rest are example, documentation or fixture manifests, which are read and counted but screened off the rules below, because both prescribe a MOVE and "align your example apps" is not a remedy), against 1 committed lockfile(s). No pinning defect was found. That is only PART of dependency hygiene, so this dimension is NOT SCORED: whether any of these packages has a newer, deprecated or abandoned release is the dependency-CURRENCY question, and answering it needs concrete resolved versions. This repository's committed lockfile WAS read and it resolves no direct production dependency to grade — a package.json states version RANGES, which name no particular release to be behind. That is a fact about this repository, not a reader we are missing. A clean pinning pass is NOT an all-clear for these dependencies, and it is not a finding that they are all USED. Note also what is deliberately NOT charged here: a workspace legitimately carries ONE lockfile for many manifests, so no row is raised off the lockfile count, only reported. Known CVEs in the same dependency graph are a separate question again, reported under D30 wherever the manifest is OSV-readable. This repository declares more than one kind of dependency manifest (an sbt build (build.sbt) and package.json), and only package.json was read here: the others remain a coverage gap in this analyzer — not a verdict that the dependencies they declare are healthy.

Appendix B — Reproduction & audit trail

Every external tool invocation behind a deep-scan dimension — the tool, its captured version, the exact command, how many findings it yielded, and a link to the retained raw output. To reproduce any finding: check out the same commit and run the command shown (repo-relative — never an absolute scratch path). The complete raw scanner output is retained verbatim under artifacts/raw/ (indexed in artifacts/raw/index.json); per-invocation exit codes and wall-clock durations are in sidecar.json — kept out of this table so the rendered report stays byte-identical across runs of the same commit.

Dimension	Tool	Version	Command	Findings	Raw output
D28 · Secrets (history)	gitleaks	—	gitleaks detect --no-banner --config /opt/gitleaks-rules/watchdog-gitleaks.toml --report-format json --report-path /tmp/watchdog-gitleaks-7f5474af39404f488024e2bcfea28d2e/history.json --exit-code 0 --source .	0	artifacts/raw/gitleaks-history.json
D28 · Secrets (history)	gitleaks	—	gitleaks detect --no-git --no-banner --config /opt/gitleaks-rules/watchdog-gitleaks.toml --report-format json --report-path /tmp/watchdog-gitleaks-7f5474af39404f488024e2bcfea28d2e/tree.json --exit-code 0 --source .	0	artifacts/raw/gitleaks-tree.json
D29 · Static Analysis (SAST)	semgrep	—	semgrep --config /opt/semgrep-rules/security-audit.yml --config /opt/semgrep-rules/owasp-top-ten.yml --config /opt/semgrep-rules/watchdog-sast.yml --json --quiet --timeout 10 --timeout-threshold 3 --metrics off --exclude .arrow --exclude .avro --exclude .csv --exclude .dat --exclude .db --exclude .feather --exclude .geojson --exclude .h5 --exclude .hdf5 --exclude .jsonl --exclude .log --exclude .ndjson --exclude .npy --exclude .npz --exclude .orc --exclude .parquet --exclude .pickle --exclude .pkl --exclude .psv --exclude .sqlite --exclude .sqlite3 --exclude .tfrecord --exclude .tsv --exclude .txt .	39	artifacts/raw/semgrep.json
D30 · Dependency Vulnerabilities	trivy	—	trivy fs --scanners vuln --format json --quiet --severity CRITICAL,HIGH,MEDIUM,LOW --skip-dirs /bin/ --skip-dirs /obj/ . --skip-db-update	0	artifacts/raw/trivy-fs.json
D31 · IaC & Container Security	trivy	—	trivy: not applicable — No Infrastructure-as-Code or container manifests found (Dockerfile, Docker Compose, Terraform, Kubernetes/Helm, CloudFormation, ARM, Bicep, Ansible); nothing to scan.	0	—
D32 · Data Compliance (PII/GDPR)	semgrep	—	semgrep: not applicable — No personal data was found crossing a boundary the PII/GDPR ruleset checks — nothing written to a log or console sink, placed in a URL or query string, or persisted to browser storage. That is a clean result for the LEAK surface only: this ruleset detects personal data escaping, it does not inventory the personal data a repository holds, so it is not evidence that this repository has no personal-data surface. The personal-data map (Appendix C) and the C1-C5 compliance cards are what speak to that.	0	—
D37 · Vulnerability-disclosure Policy	disclosure	—	disclosure: not applicable — No vulnerability-disclosure policy file found (SECURITY.md/.markdown/.rst/.txt at root or under .github/.forgejo/.gitea/docs, .well-known/security.txt). A coordinated-disclosure policy may live off-repo, so this is not evidenced rather than failed.	0	—
D40 · Network Egress Confinement	runtime-hardening	—	runtime-hardening: not applicable — No Kubernetes/orchestration workloads found in the repository manifests; network egress policy is a cluster-native control that may live at the platform/firewall layer, so there is nothing to assess here.	0	—
D41 · Kernel & Syscall Confinement	runtime-hardening	—	runtime-hardening: not applicable — No Kubernetes/orchestration workloads found in the repository manifests; seccomp/AppArmor/SELinux confinement is a workload-level control, so there is nothing to assess here.	0	—
D42 · Runtime Threat Enforcement	runtime-hardening	—	runtime-hardening: not applicable — No Kubernetes/orchestration workloads found in the repository manifests; runtime threat-detection and admission-control policy are cluster-level controls, so there is nothing to assess here.	0	—
D43 · Malicious Dependencies	trivy	—	trivy fs --scanners vuln --format json --quiet --severity CRITICAL,HIGH,MEDIUM,LOW --skip-dirs /bin/ --skip-dirs /obj/ . --skip-db-update	0	artifacts/raw/trivy-fs.json

Run 01a176c1-9681-7f9d-bfa3-6fc64647c4af · every finding is also locatable in findings.md, and the complete scoring record (with exit codes + durations) in sidecar.json.

Findings by how serious they are

This survey was produced by

Executive summary

Top priorities

Diagnosis: what the measurements show together

Architecture — module dependency graph

Architecture: which parts of the code depend on which

At a glance — Code Health · 60% · Adequate · gated by X5 ·

At a glance — Architecture · 91% · Adequate · gated by D26 ·

At a glance — Maturity · 63% · Adequate · gated by M2 ·

At a glance — Readiness · 57% · Adequate · gated by P2 ·

At a glance — Security · 78% · Adequate · gated by D36 ·

At a glance — Performance · 72% · Strong ·

Security & Compliance — OWASP Top-10 mapping

Roadmap

File quality

How the grades work

Methodology & how to trust this report

Tools & methods

Run transparency — what happened this run

Limitations & what we did not check

Per-dimension blind spots

Dimensions

Frontend & cross-cutting dimensions

Reference — by lens

Appendix A — Findings (grouped)

Appendix B — Reproduction & audit trail

Downloadable artifacts