inspector/.claude/skills/pre-push-gate/SKILL.md

name	description	disable-model-invocation
pre-push-gate	Run the mandatory pre-push gate and diagnose a failing stage — npm run format then npm run local:gate, what each stage checks, and the known traps (stale tsc cache, symlinked worktree node_modules, concurrent runs, orphaned smoke ports).	true

The pre-push gate

The rule (stated in AGENTS.md): run npm run format before committing and npm run local:gate before pushing. npm run validate is the fast inner-loop check and is not a substitute — it runs no coverage gate, no smokes, and no Storybook tests.

The reference for what each stage covers, and the CI-vs-local split, is docs/quality-gate.md. This skill is how to run it and what to do when it goes red.

The two commands

cd <repo root>
npm run format      # auto-fix: core/, scripts/, the shared surface, every client
npm run local:gate  # several minutes

local:gate is validate → coverage → verify:build-gate → verify:bundle-externals → smoke → smoke:web:firefox → local:storybook.

It is a strict superset of GitHub CI (which additionally runs npm install, and runs coverage as a parallel job). So the direction that matters holds: passing local:gate locally means CI's gates will pass. The reverse does not.

⚠️ There is no npm run ci. The gate was renamed to local:gate (#2146) precisely because npm ci is a built-in that clean-installs from the lockfile and does not run this script. npm run ci now fails with npm's missing-script error.

Verify by exit code, not by grepping output

Prettier failures are [warn] lines that match no obvious failure pattern, so a grep-based check reports success on a red run. Capture the status:

npm run local:gate; echo "EXIT=$?"

⚠️ If you run it as a background task, the harness's "exit code 0" notification describes the wrapper, not the gate — read the EXIT= line.

Diagnosing a failing stage

verify:format-coverage / format:check

Something isn't formatted, or a tracked source file is covered by no format:check glob. Run the root npm run format (it covers core/, scripts/, the shared surface, and every client) — not a single client's.

verify:typecheck-coverage

A tracked .ts/.tsx/.mts/.cts lands in no tsconfig project. Usually a new top-level file in a client whose build config roots at ./src; add it to that client's tsconfig.test.json (or the src config's include).

verify:dep-lockstep

A dependency reaching one tsc program from two installs resolves to two versions. Align the versions — bump it in every install that declares it. Do not raise the heap with --max-old-space-size; that hides the class rather than fixing it.

lint

There is no warning tier — every lint script runs --max-warnings 0, so a warning fails exactly as an error does. Fix the finding; don't widen a globalIgnores or drop the rule. If a rule genuinely must be waived on a line, use its inline disable comment with a one-line justification.

typecheck passes locally but CI's tsc -b fails

⚠️ The incremental cache hides type errors. Re-run with tsc -b --force, or in a fresh worktree.

coverage

The per-file gate is ≥90 on all four dimensions (lines, statements, functions, branches). A genuinely unreachable branch is annotated at the source with a justified /* v8 ignore … -- <reason> */, never waved through by lowering the gate. See /testing for the acceptable reasons.

Also check the file is inside a gated directory — the web coverage include is a whitelist, so a module placed outside it falls out of the gate silently.

smoke:web*

⚠️ An orphaned prod web server from a previous run fakes a rejection. It answers the readiness probe with its token, and the deep link comes back data-deeplink="rejected" with no error. Assert the port is free before blaming the change.

local:storybook

⚠️ In a worktree with a symlinked node_modules every story file fails on Vite's fs.allow. Do a real npm install in the worktree.

Everything times out at once

⚠️ Two concurrent npm run local:gate runs starve each other — ~326 tests time out at 5s. Run one at a time. (A pgrep -f "npm run local:gate" wait loop matches itself and never exits.)

Local-only steps

Two stages have no GitHub CI counterpart, each deliberately:

• smoke:web:firefox — the three browser-driven web smokes again under Firefox. Trialled as a CI job and removed (#2086): across a dozen runs it never disagreed with Chromium, and playwright install --with-deps carries a real flake surface. Kept in front of a human about to push instead.
• smoke:tui — needs a real TTY. It is invoked in CI via npm run smoke and self-skips there on process.env.CI, so it needs no guarding.

A guard (scripts/lib/workflow-gate.mjs, run by npm run test:scripts) fails the suite if a workflow invokes a local:* script, a non-Chromium engine pass, or sets SMOKE_BROWSER to anything but a literal chromium. Don't work around it — the split is the design.

Publish-only check

npm run pack:verify builds, packs the real tarball, installs it into a clean throwaway consumer, and drives the installed mcp-inspector bin end to end. It needs network access, so it is a local/release check and is in neither local:gate nor CI. Run it when touching packaging (the files allowlist, a bundler external list, anything read from disk at runtime).