Re-apply editor launch optimizations on top of externalLauncher.ts #7

Background

During the merge of origin/main into personal (merge commit b844dd40), upstream PR pingdotgg#2659 (commit d15909af, "Use Effect child process for editor launches") renamed apps/server/src/open.ts to apps/server/src/process/externalLauncher.ts and refactored the implementation to use Effect's ChildProcessSpawner.

To unblock the merge, the personal branch's two prior optimizations to open.ts were intentionally dropped rather than ported. This issue tracks re-applying them on top of the new externalLauncher.ts.

Dropped commits

• 1553907e — refactor: pre-resolve editor command map at service startup to avoid redundant availability checks

  • Added a resolveEditorCommandMap() helper that walked EDITORS once and returned a ReadonlyMap<EditorId, string>.
  • Threaded a resolvedCommands parameter through resolveEditorLaunch so per-launch isCommandAvailable walks were avoided.
  • make cached the map at service-construction time.

• 08daec60 — fix: remove pre-flight editor command availability check before launch

  • Removed the if (!isCommandAvailable(launch.command)) return yield* new OpenError(...) guard in launchDetached.
  • Used setImmediate(...) to detect ENOENT spawn errors (which arrive via process.nextTick) while letting successful spawns resolve as Effect.void.

Where to apply in the new module

apps/server/src/process/externalLauncher.ts:

1. Command map caching — add a resolveEditorCommandMap helper alongside resolveAvailableEditors, accept an optional cached map in resolveEditorLaunch (around line 267), and cache it once in make (around line 347).
2. Pre-flight check removal — the new launchEditorProcess (line 321) still has if (!isCommandAvailable(launch.command)) at line 324. The behavior should be reconsidered in the context of ChildProcessSpawner.spawn(...).pipe(Effect.flatMap((handle) => handle.unref)), which surfaces errors via Effect's error channel; the original setImmediate/ENOENT trick may not be needed if the spawner already reports ENOENT cleanly.

Verification when re-applied

• apps/server/src/process/externalLauncher.test.ts (19 tests today; add coverage for the cached-map path and the missing-command path).
• apps/server/src/server.test.ts > routes websocket rpc shell.openInEditor errors should still pass with whatever error path is chosen.