[kentcdodds]

Stack: #63 → #58 → #61 → #59 → #60

Intent

Fix the kody dev correctness and logging problems found by hands-on testing on @kentcdodds/asteroids with --target mock (CLI 1.23.0, package-app-dev.js). First of five stacked PRs: correctness + logs → live reload → agent/JSON → ports/assets/speed → polish.

Door: two-way

Cleanup: none

Summary

• No 503 on rebuild. Each rebuild starts a new workerd "generation" in its own dir. The proxy switches over only once the new one is listening. The old one drains in-flight requests (10s cap) and is then stopped. Requests that arrive mid-rebuild wait for it (10s cap), so a save never gets a 503 or the previous bundle.
• Watcher no longer stalls. fs.watch recursive is replaced by chokidar v4, which re-arms when files are replaced (sed -i, cp, atomic saves). A 1s stat poll (ino:size:mtime) over the files in the current bundle graph backs it up.
• No orphaned workerd. SIGINT/SIGTERM/SIGHUP and exit stop workerd and remove the kody-dev-* temp dir. A small detached /bin/sh reaper, fed tracked pids over a pipe, kills them and removes the dir if the CLI is SIGKILLed. Each start sweeps dirs and orphaned workerd left by dead CLI runs (owner.json), including older CLI versions.
• App console.* always streams, tagged by request ([GET /scores #12] saved 3 rows). The app entry wraps console under AsyncLocalStorage. warn and error go to stderr.
• Build errors carry file:line:col and a code frame. The header says "Could not bundle …" instead of "for local execute". Until the next good build, every request gets a dev 500 page (HTML for browsers, text otherwise, x-kody-dev-error: build), so a stale worker no longer keeps answering 200.
• Runtime errors: esbuild source maps are kept in memory and stacks are mapped back to .ts (@jridgewell/trace-mapping). Runtime wrapper frames and workerd C++ prefixes and addresses are stripped. Uncaught errors become a dev-only 500 page with the stack.
• New modules live under src/dev/: workerd-process, process-reaper, dev-watcher, dev-bundler, stack-trace, error-page, dev-events, dev-protocol. New dependencies: chokidar, @jridgewell/trace-mapping.

Testing

• npm run validate passes.
• New test/dev-server.test.ts covers: no non-200 responses while three rebuilds swap workerd; build error page with app/message.ts:1:24 and code frame, then recovery; tagged logs; a source-mapped runtime error; stack mapping; stderr cleanup; watcher ignore rules; the reaper killing pids and removing its dir when the pipe closes; and the stale-dir sweep.
• Manual testing against the built CLI on a demo app:
  • Over 15 saves, 1.23.0 returned 64–70 non-200 responses; this branch returned 0.
  • Five break/fix cycles via sed -i and via cp + mv all recovered.
  • An edit after 70s idle was picked up.
  • /boom showed at Object.fetch (app/entry.ts:9:41).
  • SIGKILL of the CLI left no workerd and no temp dir.
  • A legacy orphan (ppid 1, two-hour-old dir) was reaped on the next start.

  

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Note

Medium Risk
Large refactor of the local dev server (proxy, subprocess lifecycle, and workerd entry), but changes are confined to kody dev and not published runtime paths.

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🎉 This PR is included in version 1.23.2 🎉

The release is available on:

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