Files
ConnorYoh 4ab2505a6c Comment-quality standard, and the gate that enforces it (#7663)
## The problem

AI PRs write comments that restate the line below them, mark sections
with box drawing, and narrate the diff. Nothing in the repo said not to,
and nothing checked. `AGENTS.md` had one line about comments and it was
buried in the Python section.

Banners and `Step N:` narration have zero occurrences in the 15 months
before Aug 2025, so this is new.

## The fix

A written standard, plus a linter that enforces the mechanical part of
it on added lines only.

-
[devGuide/CODE_COMMENTS.md](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/devGuide/CODE_COMMENTS.md)
holds the reasoning and worked examples; a section in
[AGENTS.md](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/AGENTS.md)
holds the operative rules, kept short so they stay in an agent's
context. The two are split by kind rather than duplicated, because the
same prose in two places drifts.
- Rules in
[comment-rules.mjs](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs),
shared by both engines.
- Two engines. `.ts` / `.tsx` / `.mjs` go to an [oxlint JS
plugin](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-lint-oxlint-plugin.mjs)
so comments come from the parser rather than a line scan; `.java` /
`.py` go to a [line
scanner](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-lint.mjs).
Neither reads the other's files, so they cannot disagree about one file.
- Between them they read every comment form the repo writes: `//` and
`/* */`, Javadoc and JSDoc, JSX comments, `#`, and Python docstrings.
- Runs in `task pre-commit`, so the git hook and the `pre_commit.yml` CI
job both get it, and as a Claude Code [`Stop`
hook](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-lint-hook.mjs)
so an agent fixes the comment inside the turn that wrote it.

## The rules

The part worth arguing about. **Every rule blocks.** A rule that only
warns is a rule nobody acts on, so a finding you believe is wrong is a
bug in the rule: narrow it, or mark the line and say why.

| | Fires on |
| --- | --- |
|
[CMT001](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L71)
| Every word in the comment already appears in the code below it. Max 6
words, skipped for prose punctuation and for a bare Arrange/Act/Assert
marker |
|
[CMT002](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L92)
| 4+ rule or box-drawing characters, or a bare section label from [a
fixed
list](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L84)
(`Types`, `Helpers`, `State`, `Handlers`, ...) |
|
[CMT003](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L110)
| `Step N:` with a separator, or `Then,` / `Next,` / `Finally,`.
Suppressed in test files |
|
[CMT004](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L129)
| A comment about the code's own past: `this used to`, `renamed from`,
`was previously called`. Suppressed in test files |
|
[CMT005](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L154)
| 3+ consecutive comment lines where 2/3 [parse as
code](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L143)
|
|
[CMT006](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L31)
| A run of implementation comment over 12 lines, outside the first 5
lines of a file. Doc blocks are exempt, because the standard asks for
thorough contracts |
|
[CMT007](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L180)
| A parameter or return description that adds no word its name lacks.
Reads Javadoc/JSDoc `@param`, Sphinx `:param name:` and Google `name:
description` |
|
[CMT008](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L239)
| An allow directive naming a rule that does not exist, or one that
silenced nothing |
|
[CMT009](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L219)
| A `TODO` / `FIXME` / `HACK` naming no issue or link. An owner is not
accepted: a username goes stale, an issue outlives it |

Each rule carries the readings it deliberately excludes, next to the
rule. Those exclusions came from running the rules over this repo, not
from taste: `CMT004` does not match a bare "no longer needed" because
that is as often about runtime lifecycle as about history, and `CMT003`
needs a separator after the number so a wrapped line beginning "step 2
unmounts + remounts the panel" reads as the prose it is.

A comment sharing a line with code is judged by the rules that do not
depend on the code below it, so a trailing `// TODO fix this` or `/*
this used to run before the flush */` still reports, while `50L * 1024 *
1024 // 50 MB` does not. `CMT001` would have been wrong about six in
seven trailing comments here, so it stays out of them.

If a finding is wrong, `// comment-lint-allow: CMT002` on the line
above. Rule-specific, [no blanket
disable](https://github.com/Stirling-Tools/Stirling-PDF/blob/claude/ai-pr-comment-quality-dd970e/scripts/lint/comment-rules.mjs#L229).
A directive naming a rule that does not exist, or silencing nothing, is
itself a `CMT008` failure, so a typo cannot quietly disable a rule and a
stale one gets deleted rather than accumulating.

No native linter covers `CMT007`. `eslint-plugin-jsdoc`'s
`require-param-description`, Checkstyle's `NonEmptyAtclauseDescription`
and ruff's D-rules all check that a description exists, not whether it
says anything.

## Scoping

Added comment **text** only, not lines git calls new. Reindenting a file
or moving a block makes git mark untouched comments as added; findings
are matched against the comment text at the base, so only genuinely new
content reports.

The whole file is read and every comment in it evaluated. Only the
*reporting* is filtered, so a rule still sees the code a comment
introduces, the full run it belongs to, and the base version of the
file.

Existing tree is untouched. `task pre-commit:comment-lint:all` reports
it and always exits 0:

| | java | ts/js | py |
| --- | --- | --- | --- |
| findings | 1,218 | 741 | 204 |

2,163 across 542 files, mostly `CMT002` banners (1,482) and `CMT001`
restatements (456). Clearing it is separate work, by directory.

Not in this PR: an advisory LLM review layer for the things no pattern
can judge.

## Verification

Run against
[#7494](https://github.com/Stirling-Tools/Stirling-PDF/pull/7494) as CI
would, in a throwaway worktree: **two findings on a 78 file, +4,512 line
change, both genuine banners, in 952ms**. A whole-file scan of those
same files gives 11; the other 9 were withheld because that PR's author
did not write them, and they are the `@param teamId the team ID` shape
this standard exists to stop.

Both scanners blank string and character literals before looking for
comment markers, because a partial lex desynchronises everything after
it: one apostrophe in a Java comment, or one Python template whose
closing quotes start a line, is enough to read dozens of lines of code
as a single comment. Two fixtures carry canaries that stop being
reported if either engine ever desynchronises again.

The [fixture
corpus](https://github.com/Stirling-Tools/Stirling-PDF/tree/claude/ai-pr-comment-quality-dd970e/scripts/lint/fixtures)
pins all 9 rules against both engines, and `--selftest` fails if the two
disagree about the same file.

## Two things reviewers should know

**The oxlint JS plugin API is alpha.** oxlint itself is stable and
already this repo's frontend linter; the plugin API is the new
dependency. Its documented failure mode
([oxc#25203](https://github.com/oxc-project/oxc/issues/25203)) is being
skipped silently while oxlint still reports success. That affects the
standalone release binary rather than the npm package this invokes, but
the class of failure reads exactly like clean code, so the run asserts
`number_of_rules >= 1` from oxlint's own report and a broken engine
exits 2 rather than passing. If the API ever breaks, the fallback is
folding these rules into the line scanner, which already implements all
nine for Java and Python.

**`.claude/settings.json` is now committed**, carrying the hook and
nothing else: 19 lines, no `permissions`, nothing machine-specific. That
partly reverts `c35546a212` ("Ignore claude dir"), which existed because
this file had twice been committed by accident with a personal
`permissions` allowlist, once with absolute machine paths. Personal
config still belongs in `.claude/settings.local.json`, which the new
pattern keeps ignored, and hook entries merge across the two so nobody's
own hooks are lost.

If you already hand-wrote a `.claude/settings.json`, copy it somewhere
first: that path used to be git-ignored, and git overwrites an ignored
file without warning when a commit starts tracking it. Across 19 local
checkouts here, 13 have `settings.local.json` and none has a
hand-written `settings.json`.

To turn the hook off, `{ "env": { "COMMENT_LINT_HOOK": "0" } }` in local
settings. Claude Code can only disable all hooks at once, hence the
switch. The commit-time gate still applies.

## How to test

```bash
task pre-commit:comment-lint:ci
```

The fixture corpus, then the diff. The corpus checks the rules
themselves rather than the code under review, so it runs on CI and
before a rule change, not on every local commit.

```bash
task comment-lint:branch
```

`clean (34 files in scope)`. `task comment-lint` is the same thing
scoped to uncommitted work, which is what the git hook and CI run.

To watch it bite, add `// Is banner` above `export function isBanner` in
`scripts/lint/comment-rules.mjs` and run `task comment-lint`: one
`CMT001`, exit 1. The gate covers its own source, which is why these
scripts have no section dividers.

```bash
task pre-commit:comment-lint:all
```

The standing backlog, report-only.

Verified on the pinned oxlint 1.77.0, not only the 1.79 the plugin was
prototyped against.
2026-08-28 10:56:50 +00:00

220 lines
7.9 KiB
YAML

version: '3'
# Repo-wide lint/format/secret checks - the single source of truth that the git
# pre-commit hook (.pre-commit-config.yaml) and CI (pre_commit.yml) both call.
vars:
# File selections as git pathspecs: git does the include/exclude matching, so
# there is no grep/xargs and it behaves identically on every platform.
PY_FILES: >-
'scripts/*.py'
'.github/scripts/*.py'
'app/core/src/main/resources/static/python/*.py'
':(exclude)*split_photos.py'
':(exclude)scripts/lint/fixtures/*'
SPELL_FILES: >-
'*.html'
'*.css'
'*.js'
'*.py'
'*.md'
':(exclude).vscode/*'
':(exclude).devcontainer/*'
':(exclude)app/core/src/main/resources/*'
':(exclude)app/proprietary/src/main/resources/*'
':(exclude)frontend/editor/public/vendor/*'
':(exclude)*Dockerfile*'
':(exclude)*pdfjs*'
':(exclude)*thirdParty*'
':(exclude)*bootstrap*'
':(exclude)*.min.*'
':(exclude)*diff.js'
WS_FILES: >-
'*.js'
'*.java'
'*.py'
'*.yml'
':(exclude)*pdfjs*'
':(exclude)*thirdParty*'
':(exclude)*bootstrap*'
':(exclude)*.min.*'
':(exclude)*diff.js'
':(exclude).github/workflows/*'
LOCALE_TOML: 'frontend/editor/public/locales/*/translation.toml'
# gitleaks is pinned + checksum-verified by scripts/pre-commit/install_gitleaks.py,
# which owns the version and caches the binary here.
GITLEAKS_BIN: '.task/bin/gitleaks{{if eq OS "windows"}}.exe{{end}}'
env:
# Keep repository-wide checks isolated from the engine runtime environment.
UV_PROJECT_ENVIRONMENT: '.venv-pre-commit'
tasks:
default:
desc: "Check formatting, spelling, and secrets across the repo"
cmds:
- task: ruff
- task: ruff-format
- task: codespell
- task: gitleaks
- task: whitespace
- task: toml-sort
- task: comment-lint
fix:
desc: "Auto-fix formatting, spelling, and secrets issues across the repo"
cmds:
# Auto-fixers first, then the report-only tools (codespell, gitleaks) so a
# finding there does not stop the fixers from running.
- task: ruff
vars: { FIX: '1' }
- task: ruff-format
vars: { FIX: '1' }
- task: whitespace
vars: { FIX: '1' }
- task: toml-sort
vars: { FIX: '1' }
- task: codespell
- task: gitleaks
- task: comment-lint
install:
desc: "Install the pinned pre-commit Python tools"
run: once
cmds:
- uv sync --project engine --locked --group pre-commit
sources:
- engine/uv.lock
- engine/pyproject.toml
status:
- test -d engine/.venv-pre-commit
clean:
desc: "Remove the cached gitleaks binary and the pre-commit virtualenv"
cmds:
- cmd: rm -rf engine/.venv-pre-commit .task/bin/gitleaks
platforms: [linux, darwin]
- cmd: cmd /c "rmdir /s /q engine\.venv-pre-commit & del /q .task\bin\gitleaks.exe"
platforms: [windows]
ignore_error: true
# Individual checks (hidden from `task --list`, but callable, e.g.
# `task pre-commit:toml-sort FIX=1`). Pass FIX=1 to auto-fix where supported.
ruff:
deps: [install]
cmds:
- uv run --project engine --locked --group pre-commit ruff check --isolated --line-length=120 {{if .FIX}}--fix {{end}}$(git ls-files {{.PY_FILES}})
ruff-format:
deps: [install]
cmds:
- uv run --project engine --locked --group pre-commit ruff format --isolated --line-length=120 {{if .FIX}}{{else}}--check {{end}}$(git ls-files {{.PY_FILES}})
codespell:
deps: [install]
cmds:
- uv run --project engine --locked --group pre-commit codespell --ignore-words-list=thirdParty,tabEl,tabEls,Sie,ist,fulfilment --quiet-level=2 $(git ls-files {{.SPELL_FILES}})
toml-sort:
deps: [install]
cmds:
- uv run --project engine --locked --group pre-commit python scripts/pre-commit/sort_locale_toml.py {{if .FIX}}--fix {{end}}{{.LOCALE_TOML}}
whitespace:
cmds:
- uv run --project engine --locked --group pre-commit python scripts/pre-commit/whitespace.py {{if .FIX}}--fix {{end}}{{.WS_FILES}}
gitleaks:
deps: [gitleaks-bin]
# Scan staged changes only, matching the old hook: the git-mode fingerprints
# in .gitleaksignore (file:rule:line) still apply, and with nothing staged
# this is a no-op. Secrets are never auto-fixed, so FIX has no effect.
cmds:
- "{{.GITLEAKS_BIN}} git --pre-commit --redact --staged --verbose"
comment-lint:
desc: "Check comment quality on the lines this branch adds"
summary: |
Blocks a comment that restates the code below it, a section banner, or a
block of commented-out code. Everything else it reports is advisory.
Scoped to added lines, so touching an old file never surfaces the standing
backlog. The standard is devGuide/CODE_COMMENTS.md.
With no arguments it diffs the working tree against HEAD, which is what a
pre-commit run wants: the lines you are about to commit. On a CI pull request
it diffs against the target branch instead, via GITHUB_BASE_REF.
To ask what a whole branch adds instead, use the branch variant, which
needs no argument passing:
task comment-lint:branch
Full tree (report only): task pre-commit:comment-lint:all
Fixture corpus: task pre-commit:comment-lint:selftest
# Depends on the frontend install because the .ts/.tsx half of the rule set
# runs as an oxlint plugin. Without it the TS engine warns and skips, which
# would leave the frontend silently unchecked on CI.
deps: [":frontend:install"]
cmds:
- node scripts/lint/comment-lint.mjs {{.CLI_ARGS}}
comment-lint:branch:
desc: "Check comment quality on everything this branch adds over its base"
summary: |
Like `task comment-lint`, but scoped to the whole branch rather than to
uncommitted work, so it still reports after you commit.
Exists as its own task because passing `-- --since origin/main` through Task
is not portable: with the npm build of Task the launcher is a PowerShell
script, and PowerShell strips the `--` before Task sees it, leaving Task to
print its own usage.
Override the base with BASE=<ref>.
vars:
BASE: '{{.BASE | default "origin/main"}}'
deps: [":frontend:install"]
cmds:
- node scripts/lint/comment-lint.mjs --since {{.BASE}}
comment-lint:ci:
desc: "Comment gate as CI runs it: fixture corpus, then the diff"
summary: |
The corpus checks the rules themselves rather than the code under review, so
it belongs on CI and not on every local commit. Run this before changing a
rule, and let CI run it on every pull request.
deps: [":frontend:install"]
cmds:
- node scripts/lint/comment-lint.mjs --selftest
- node scripts/lint/comment-lint.mjs {{.CLI_ARGS}}
comment-lint:hook:
desc: "Comment gate for the editor hook: everything this turn changed"
summary: |
Same scope as `task comment-lint`, kept as its own name so the hook has a
stable entry point and the taskfile shows every way the linter is invoked.
Not in the frontend-install dependency chain on purpose: this runs at the end
of every turn, so it stays as short as it can be. If oxlint is missing the TS
half warns and skips.
cmds:
- node scripts/lint/comment-lint.mjs
comment-lint:all:
desc: "Report every comment finding in the tree (never fails)"
deps: [":frontend:install"]
cmds:
- node scripts/lint/comment-lint.mjs --all
comment-lint:selftest:
desc: "Check both comment-lint engines against the fixture corpus"
deps: [":frontend:install"]
cmds:
- node scripts/lint/comment-lint.mjs --selftest
gitleaks-bin:
internal: true
desc: "Ensure the pinned, checksum-verified gitleaks binary is cached in .task/bin"
cmds:
- uv run --project engine --locked --group pre-commit python scripts/pre-commit/install_gitleaks.py