Run the Playwright suite in CI

[wormeyman]

Why now

The 192 browser specs ran nowhere but a maintainer's laptop. That stopped being theoretical this week: PR #222 arrived with every check green and a blueprint-round-trip.spec.ts failure in it.

Measured on that branch — 191 passed, 1 failed:

-   "serializedHash": 825830683,
+   "serializedHash": 120098912,

Every count and both position checksums held, which is the signature of a field dropped from serialized JSON with no geometry change. The field is position-relative-to-grid, and a decode of the corpus says who it affects: 325 of 367 blueprints carry snapping and all 325 are absolute-snapping: true — exactly the branch the new serialize condition excludes.

Neither vp check nor vp test can see any of it. The decode → model → serialize path needs FD loaded, which needs a browser and the sprite server.

What it costs, and what it doesn't need

No Factorio and no unpinned network. The corpus is committed under test-blueprints/ and the sprite data under packages/exporter/data/output, so this stays as offline as the rest of CI. A separate job, parallel to checks like rust is — ~5 minutes at the config's workers: 1.

Three choices worth stating

Each has a wrong version that looks right:

• Reuses npm run localpreview rather than carrying its own copy of how to start the two servers. A second copy is a bound written down twice, and the one that loses is the one nothing tests.
• The browser cache keys on the resolved @playwright/test version read out of node_modules, not the caret range in package.json. The resolved version decides the browser build, so keying on ^1.62.0 serves yesterday's browser to today's Playwright — which fails as a missing chrome-headless-shell and reads as a suite-wide regression rather than a cache miss.
• The server step redirects stdout to a file instead of inheriting it. A backgrounded process holding the step's stdout pipe open can stop that step from ever completing.

Deploy is gated on it, and the sprite server is pinned

Both were flagged as open in the first commit and are closed in the second.

deploy now needs [checks, e2e]. Gating on checks alone leaves exactly the #222 failure class free to reach fbe.factorygamefan.com. Costs ~5 minutes on the deploy path.

serve becomes a declared devDependency instead of an npx --yes fetch. Unpinned was fine while localpreview only ran on a laptop; as a CI dependency it was a run-time-resolved package in a job whose previous step is vp install --frozen-lockfile. ~990 lockfile lines for a dev-only static file server, in exchange for reproducibility and Renovate tracking it.

Stale claims corrected

Eight comments across six files asserted Playwright does not run in CI (playwright.config.ts, vite.config.ts, zoomLevels.ts, zoomLevels.test.ts, zoom-ladder.spec.ts, blueprint-files.test.ts, plus two in CLAUDE.md). The reasoning under each survives — a pure unit test still answers in seconds inside checks where this job takes five minutes and two dev servers — but the flat claim does not. The split is now about cost rather than coverage.

Verification

• vp check . clean — 230 files formatted, 0 warnings/lint/type errors
• vp test — 180 passed
• Full Playwright suite locally on this base — 192 passed (4.6m)
• The Playwright job passed on this PR's own first run, every step including server startup and all 192 specs
• npx --no-install serve --version → 14.2.6, so nothing is fetched; localpreview still brings both ports up with data.json 200 off 8081
• actions/upload-artifact SHA verified against the live v4 tag

🤖 Generated with Claude Code

https://claude.ai/code/session_017Dbza77QEZnkqt1mGssY71