## Symptom
Grafana's \`app-crash-log\` alert fires on every deploy. The Loki query
that backs it (\`ERR_|FATAL|uncaughtException|…\`) matches:
Error [ERR_MODULE_NOT_FOUND]: Cannot find module
'/app/apps/journal/app/lib/logger.server' imported from
'/app/apps/journal/app/lib/email.server.ts'
A real bug, not a false positive: \`email.server.ts\` line 2 was
\`import { logger } from \"./logger.server\"\` — no extension.
## Why typecheck didn't catch it
\`tsconfig.base.json\` sets \`moduleResolution: \"bundler\"\`. The bundler
resolver accepts extensionless relative imports because Vite / esbuild
/ webpack resolve them at build time. TypeScript was happy.
Production runs \`node --experimental-strip-types server.ts\`, which
uses Node's NodeNext ESM resolver — strict about extensions. The two
resolvers disagree silently for files Node loads directly (server.ts,
\`.server.ts\` modules dynamically imported from it, and jobs).
## Fix
1. **Added \`.ts\` extensions to the 4 broken imports** I could find:
- \`apps/journal/app/lib/email.server.ts\` → \`./logger.server.ts\`
(the actual deploy-blocker)
- \`apps/planner/app/lib/brouter.ts\` → \`./route-merge.ts\`, \`./http.server.ts\`
- \`apps/planner/app/lib/use-nearby-pois.ts\` → \`./overpass.ts\`
- \`packages/map/src/MapView.tsx\` → \`./layers.ts\` (caught by the rule)
2. **Added \`eslint-plugin-import-x\` with \`import-x/extensions: always\`**,
scoped to files Node actually executes raw:
- \`apps/*/server.ts\`
- \`apps/*/app/lib/**/*.server.ts\`
- \`apps/*/app/jobs/**/*.ts\`
- \`packages/*/src/**/*.{ts,tsx}\`
Ignored: route-scoped \`*.server.ts\` files (bundled by Vite into the
React Router build, never loaded by Node), and test files (Vitest's
own resolver).
## What's still possible
- Non-\`.server.ts\` files in \`app/lib\` (e.g. \`legal.ts\`, \`actor-iri.ts\`)
could still ship extensionless imports. They're not in the lint
scope. If one breaks at runtime we can extend the glob — for now
they tend to be tiny utility modules that don't import other
relatives.
- The deeper fix would be \`moduleResolution: nodenext\` for server-side
tsconfig, or bundling the server code so Node never sees raw \`.ts\`.
Bigger surgery; the lint rule covers the failure mode for now.
Full repo: pnpm typecheck / lint / test all green after \`pnpm install\`.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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