ts-folder-check

Scoped TypeScript error checker. Type-checks only the specified folder(s) instead of the whole project, so it runs much faster than a full tsc --noEmit on a large codebase or monorepo.

Install

# bun
bun add -d ts-folder-check

# npm
npm install -D ts-folder-check

typescript (6.0.3) is a dependency.

Usage

Run from the project root (where your tsconfig.json lives), passing one or more folder paths relative to the root:

ts-folder-check <folder> [folder2]... [--include <dir[,dir2]>]

Examples:

bunx ts-folder-check <relative-folder-path>

# multiple folders
bunx ts-folder-check <relative-folder-path> <relative-folder-path>

# project has global .d.ts files (e.g. vite-env.d.ts) outside the target folders
bunx ts-folder-check <relative-folder-path> --include types

Or as a package.json script:

{
  "scripts": {
    "ts-folder-check": "ts-folder-check --include types"
  }
}

bun ts-folder-check <folder>

# with npm, extra arguments need "--"
npm run ts-folder-check -- <folder>

Options

| Option | Description | | ----------------- | -------------------------------------------------------------------------------------------------------- | | --include <dir> | Extra folder(s) with global .d.ts files that must be loaded but not type-checked. Comma-separated list. |

What it does

• Uses the TypeScript Compiler API directly (no bunx/npx spawning, so no Windows/shell issues).
• Reads the nearest tsconfig.json, so path aliases resolve correctly.
• Type-checks only the files inside the target folder(s); imported files are parsed for types but not deeply checked (10x+ faster on a large project).
• Caches results incrementally in .tscheck/ — repeated runs on the same folder are faster. Add .tscheck/ to your .gitignore.
• Exits with code 1 if errors are found, 0 otherwise. Config or path problems are reported clearly, never hidden.

License

MIT