tsconfig.typecheck.json

{
  // Source-health typecheck. Identical compiler options to tsconfig.json, but it
  // never reads Next's generated route types under `.next/`.
  //
  // Why this file exists (see docs/outstanding-issues.md #210): the base config
  // includes `.next/types/**/*.ts` and `.next/dev/types/**/*.ts`, which are
  // gitignored build artifacts. Delete or rename a page — a mockup route, most
  // often — and the stale generated validator still imports the removed module,
  // so `npm run typecheck` reports errors that no longer exist in source. CI
  // never sees it (fresh checkout, no `.next`), so the gate reads as red locally
  // and green in CI, and gets abandoned. A permanently-red gate is why real type
  // errors reach CI instead of being caught before push.
  //
  // Route-signature validation is NOT lost: `next build` (CI's Build job) still
  // typechecks the generated types against the real routes. This config answers
  // the narrower question the pre-push guard needs — "is the source itself
  // sound?" — deterministically, without depending on build-artifact freshness.
  //
  // Incremental cache: pin a distinct buildinfo so a direct
  // `tsc -p tsconfig.typecheck.json` does not collide with the base config's
  // `tsconfig.tsbuildinfo` (extends inherits that path and TypeScript discards
  // the cache when root-file sets differ). `scripts/run-heavy.mjs` still
  // injects a per-worktree `--tsBuildInfoFile` under tmp for
  // `typecheck:source:internal`, which overrides this pin across shared
  // node_modules checkouts.
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "tsBuildInfoFile": "node_modules/.cache/tsc/tsconfig.typecheck.tsbuildinfo"
  },
  // `next-env.typecheck.d.ts` stands in for `next-env.d.ts`, which Next 16
  // regenerates with `import "./.next/dev/types/routes.d.ts"` in it. An
  // `exclude` cannot drop a file that an included file imports, so that one line
  // silently reinstated the `.next` dependency this config exists to remove.
  // `next-env.d.ts` is excluded explicitly because `**/*.ts` matches `.d.ts`
  // too, so dropping it from `include` alone would not keep it out.
  "include": ["next-env.typecheck.d.ts", "**/*.ts", "**/*.tsx", "**/*.mts"],
  "exclude": [
    "node_modules",
    ".next/**",
    "next-env.d.ts",
    "scratch/**",
    "supabase/functions/**",
    "worktrees/**",
    "scripts/archive/**"
  ]
}