feat(web): PLAN §4.8 — MSW, Knip, and Vitest coverage gate

[mcalthrop]

Summary

Completes PLAN §4.8: MSW-backed tests, Knip, and a Vitest coverage gate in CI.

Changes

• MSW: Default handlers, test server, and Vitest setup; page tests use server.use instead of mocking @/api.
• Errors: formatFetchError unwraps Solid createResource / Error.cause so API JSON messages surface in alerts.
• Knip: knip.json with sensible ignores (generated API barrel, UI primitives, tests); non-exported RecipeDetailPanelProps.
• Coverage: 100% lines, statements, and functions on included sources; src/components/ui/** and src/api/client.ts excluded; branch threshold omitted (v8 is noisy on JSX). coverage/ gitignored.
• CI: pnpm --filter web knip and pnpm --filter web test:coverage.
• TypeScript: apps/web target / lib ES2024 for Promise.withResolvers in tests.
• Script: assert-no-function-declarations uses \bfunction\b so thresholds.functions is not a false positive.

Testing

• pnpm lint
• pnpm --filter web test:coverage
• pnpm --filter web knip
• pnpm build

Made with Cursor

[Copilot]

Pull request overview

Implements PLAN §4.8 for the web app by introducing MSW-backed Vitest tests, adding Knip dead-code checks, and enforcing a strict Vitest coverage gate in CI, alongside improved UI error formatting for API failures.

Changes:

• Add MSW test infrastructure (handlers/server/Vitest setup) and migrate existing page/app tests to server.use(...) overrides.
• Introduce formatFetchError and update pages to surface API JSON { message } errors in destructive alerts.
• Add Knip + Vitest coverage scripts/config, wire them into Turbo and GitHub Actions CI (and ignore coverage/ output).

Reviewed changes

Copilot reviewed 23 out of 24 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
turbo.json	Adds Turbo tasks for test:coverage and knip.
pnpm-lock.yaml	Locks new dev dependencies (MSW, Knip, Vitest coverage provider) and transitive deps.
PLAN.md	Marks PLAN §4.8 as completed.
package.json	Adds root scripts for test:coverage and knip via Turbo.
apps/web/vite.config.ts	Adds Vitest setup + env and configures v8 coverage thresholds/exclusions.
apps/web/tsconfig.app.json	Bumps target/lib to ES2024 for Promise.withResolvers in tests.
apps/web/src/test/vitest-setup.ts	Global MSW server lifecycle hooks for Vitest.
apps/web/src/test/msw/server.ts	Creates a shared MSW node server with default handlers.
apps/web/src/test/msw/handlers.ts	Defines default MSW handlers for recipe list/detail endpoints.
apps/web/src/test/msw/constants.ts	Centralizes the API base URL used by MSW tests.
apps/web/src/pages/RecipePage.tsx	Uses formatFetchError for user-facing error alerts.
apps/web/src/pages/RecipePage.test.tsx	Switches RecipePage tests from API mocking to MSW handlers.
apps/web/src/pages/RecipePage.missing-id.test.tsx	Adds coverage for empty route param id behavior.
apps/web/src/pages/Home.tsx	Uses formatFetchError for user-facing error alerts.
apps/web/src/pages/Home.test.tsx	Switches Home tests from API mocking to MSW handlers (incl. loading gate).
apps/web/src/lib/format-fetch-error.ts	Adds error unwrapping/formatting helper for UI alerts.
apps/web/src/lib/format-fetch-error.test.ts	Adds unit tests for formatFetchError.
apps/web/src/components/recipe-detail/RecipeDetailPanel.tsx	Makes props type non-exported (Knip cleanup).
apps/web/src/App.test.tsx	Migrates App tests to MSW and adds navigation coverage.
apps/web/scripts/assert-no-function-declarations.mjs	Tightens regex to avoid false positives on functions:.
apps/web/package.json	Adds test:coverage and knip scripts + dev dependencies.
apps/web/knip.json	Adds Knip configuration and ignores for generated/UI/test files.
apps/web/.gitignore	Ignores coverage output directory.
.github/workflows/ci.yml	Adds web Knip + web coverage-gated Vitest runs to CI.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

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