tsbuildinfo-cache-gotcha

name	tsbuildinfo-cache-gotcha
description	**Description:** Use when debugging missing TypeScript build output in composite/incremental projects, especially after cleaning dist/ directories.

TypeScript .tsbuildinfo Cache Skips Emission When dist/ Is Deleted

Description: Use when debugging missing TypeScript build output in composite/incremental projects, especially after cleaning dist/ directories.

The Problem

When a TypeScript project uses composite: true (required for project references), tsc writes a .tsbuildinfo file for incremental builds. If you delete the dist/ directory but leave .tsbuildinfo in place, tsc will:

1. Read .tsbuildinfo and conclude nothing has changed
2. Exit successfully with code 0
3. Emit zero files — dist/ stays empty

This is silent — no warnings, no errors. tsc --listEmittedFiles will also show nothing.

The Fix

Always delete .tsbuildinfo before building when you need guaranteed output:

rm -f tsconfig.tsbuildinfo && tsc

Or in package.json:

{
  "scripts": {
    "build:clean": "rm -f tsconfig.tsbuildinfo && tsc"
  }
}

Where This Hits in Flightdeck

• packages/shared/tsconfig.json has composite: true for project references
• packages/server depends on @flightdeck/shared which resolves to packages/shared/dist/
• In a fresh clone or after rm -rf dist/, running npm run build in shared would silently produce nothing if .tsbuildinfo was stale

Detection

If tsc exits 0 but dist/ is empty or missing expected files:

1. Check for a .tsbuildinfo file in the project root
2. Delete it and rebuild
3. If files now appear, the cache was stale