tsc-shame

Find heavy node_modules slowing down your tsc type checking

Usage

Go inside a TypeScript project and run:

npx tsc-shame

# Generating trace with tsc...

# Top packages by findSourceFile duration:
# =========================================================================
# googleapis         | ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 1882.4ms
# @nextui-org/react  | ■■■■■■■■■ 344.1ms
# @sentry/remix      | ■■■■■■■ 262.5ms
# @sentry/node       | ■■■■■■ 210.5ms
# next-auth          | ■■■ 115.8ms
# @types/node        | ■■ 91.7ms
# @remix-run/react   | ■■ 91.0ms
# next               | ■■ 78.5ms
# react-router-dom   | ■■ 68.7ms
# @elysiajs/eden     | ■■ 67.4ms
# stripe             | ■■ 66.5ms
# elysia             | ■■ 65.1ms
# vitest             | ■ 56.1ms
# @sinclair/typebox  | ■ 50.6ms
# kysely             | ■ 49.9ms
# @prisma/client     | ■ 49.8ms
# @types/react       | ■ 48.2ms
# lucide-react       | ■ 47.3ms
# @nextui-org/system | ■ 44.0ms
# @sentry/core       | ■ 43.4ms

# For more details on which node_modules files are causing the slowdown, refer to the tsc tracing guide:
# https://github.com/microsoft/TypeScript-wiki/blob/main/Performance-Tracing.md

This command will generate a trace of the tsc execution and then print a bar graph of the slowest packages to type check.

This tool helped me remove googleapis from my project, which cut in half type checking time.

How it works

Under the hood, tsc-shame:

1. Runs tsc with the following options:

   • --incremental false - Disables incremental compilation
   • --composite false - Disables composite project mode
   • --generateTrace <tempDir> - Generates trace data in a temporary directory

2. The trace data is saved to a trace.json file which contains detailed timing information about TypeScript's compilation process, including:

   • Time spent checking each source file
   • Time spent finding and loading files
   • Time spent binding types

3. tsc-shame then analyzes this trace data to:

   • Group events by file/package name
   • Calculate total duration for each file/package
   • Sort them by duration to identify the slowest ones

4. Finally, it generates two bar graphs showing:

   • Top files by checkSourceFile duration - Shows which individual files take longest to type check
   • Top packages by findSourceFile + bindSourceFile duration - Shows which node_modules packages are slowest overall

This helps identify which dependencies are causing TypeScript performance bottlenecks, allowing you to:

• Remove or replace slow dependencies
• Consider moving slow dependencies to devDependencies if they're only needed for development
• Split up large files that are slow to type check

License

MIT