Run vitest 4.1.11 in the browser shell (goal vitest-run-in-browser)

[vanilla-wave]

Delivered

npm install + vitest run for vitest 4.1.11 / vite 8.0.16 in the rifty shell, with the project's own vitest.config.ts and TypeScript tests. Both pools work (forks default, threads), the reporter prints real pass/fail lines, counts and the assertion diff, and the process exits with Node's code (fail → 1, fix → 0). npm test and --reporter=verbose behave the same. Compat page: docs/public/compat/vitest.md.

Every wall is fixed as a generic Node contract. There are no vitest/vite/cac-shaped patches.

#	Node contract	ADR
1	npm bare-version overrides ("vite": "8.0.16")	0451
2	node:path/posix builtin	—
3	Node-own process members as named ESM imports	—
4	named-loud fs.statfsSync / child_process.spawnSync / process.memoryUsage	0443
5	Function guard checks computed global keys at runtime (throws only for 'Function')	0444
6	Readable.pipe(process.stdout) never ends stdio	—
7	uncaughtException / unhandledRejection / 'exit' / exit() ↔ exitCode	0445
8	live Worker = keepalive handle; run-to-completion exit; Node unref shape	0446
9	fork(..., {serialization:'advanced'}) as native structured clone	0448
10	vm lineOffset/columnOffset via one owned stack hook	0450
11	Worker.stdout/stderr; --require/--conditions/--experimental-import-meta-resolve on fork + Worker	0449
13	ref'd MessagePort keepalive (emnapi holds rolldown async work this way)	0447
12	acceptance e2e tests/e2e/vitest-run.spec.ts; loud vm.constants/http.Agent ceilings for unclaimed modes	0464

Outside the claim, modes fail loudly: jsdom/happy-dom, coverage, browser mode and vm pools each hit a named NotImplementedError. Watch mode and other vite versions are ⚠️ unclaimed, with the observed boundary stated (user amendment, 2026-09-23).

Process

• Each child passed an independent Contract+RED and Final+GREEN review. Verdicts are in docs/backlog/*/reference/*-{contract-red,final-green}.json.
• Four regressions found after landing were fixed via rifty-fix, with a baseline, a RED test and a root fix each:
  • Workbench close race;
  • no-COI declared gap hidden behind a fatal exit;
  • no-COI exit statuses;
  • runBin timers/listeners surviving past process exit.
• Whole-goal CLOSE review: PASS, goal_complete: true, 18/18 coverage. Binding verdict: docs/backlog/runtime-js/reference/vitest-run-in-browser-final-green.json @ 57f6117. An independent codex review found the runBin blocker, which is fixed.
• User decisions, recorded in docs/backlog/runtime-js/reference/vitest-run-in-browser-evidence.md §Goal record:
  • I7 option A: watch mode and other vite versions are unclaimed; no bans.
  • Late-rejection option B: narrow the claim and track the gap in backlog.
• Discoveries went to backlog drafts, each with a fresh RDY-6 check. Every overturned ADR clause had a DEC-2 review.
• browser-unit CI Node is pinned to 24.16.0, the version of the frozen oracle rows (PR-4, reviewed).

Prior draft attempts #349, #351 and #352 were used as evidence only; no code was taken from them.

Test plan

• pnpm pr:check 25/25 on the reviewed tree
• CI green: unit, parity, browser-unit, no-COI, e2e light/heavy (incl. vitest-run.spec.ts), prod, hosted
• pnpm check:pass-binding OK

🤖 Generated with Claude Code

[github-actions]

Netlify preview: https://pr-353--rifty-playground.netlify.app
Immutable deploy: https://pr-353--rifty-playground.netlify.app
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[greptile-apps]

Confidence Score: 4/5

[High risk] Closes vitest-in-browser goal; updates build and runtime architecture.

The PR needs the registry-URL requirement satisfied before merging; the Worker constructor listener cleanup is a non-blocking improvement.

Findings

1.  Hardcoded npm registry URL ▶

Summary

The PR adds browser-shell support for vitest run with vitest 4.1.11 and Vite 8.0.16, backed by changes across npm resolution, Node process and worker contracts, IPC, module loading, and acceptance tests.

• The npm override probe needs an environment-configured registry URL.
• Worker construction should not leave stdio pipe listeners behind when validation fails.

_{Reviews (1) · Last reviewed commit: "Bind vitest goal final verdict at the re..."}

[greptile-apps]

Hardcoded npm registry URL The new probe fixes the registry to https://registry.npmjs.org/ and passes that value to every spawned npm process, overriding any configured registry or mirror. The repository requires external URLs to come from environment configuration. This requirement must be satisfied before merging.

Context Used: CLAUDE.md (source)

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!

[greptile-apps]

Comments Outside Diff

These findings sit on lines the diff does not cover, so they could not be posted inline. Each one leaves this list once its file changes.

•  Stdio listeners survive failed construction packages/runtime-js/src/builtins/worker_threads.ts:134 ▶

  A kernel-backed Worker pipes its stdout and stderr to the owner before process-context and environment validation finishes. If that validation throws, construction stops without ending those streams or removing their listeners. Repeated invalid constructions can therefore accumulate unused listeners on the owner's streams.