React Compiler Check

0.1.11 verified Fri May 01 auth: no javascript

A CLI tool that scans React projects for code patterns incompatible with React Compiler. Version 0.1.11, pre-1.0 with monthly releases. Detects legacy patterns (string refs, Legacy Context), impure renders (setTimeout, fetch in render), improper hook usage (hooks in loops/conditions), direct state mutations, and dynamic objects. Provides actionable suggestions. Lightweight, zero-config, integrates with ESLint via optional plugin. Unlike React Compiler's built-in checks, this is a standalone diagnostics tool for existing codebases.

Common errors

error Error: Cannot find module 'react-compiler-check' ↓

cause Package not installed globally or locally, or not in node_modules.

fix

Install locally: npm install react-compiler-check --save-dev. Or use npx: npx react-compiler-check

error TypeError: check.run is not a function ↓

cause Using default import in ESM when only named export exists.

fix

Use import { run } from 'react-compiler-check'

error SyntaxError: Unexpected token 'export' ↓

cause Running in a CJS environment without transpilation.

fix

Use require('react-compiler-check') or configure your bundler to handle ESM.

Warnings

gotcha Tool scans .ts and .tsx files but requires TypeScript installed separately if your project uses TypeScript. ↓

fix Install typescript as a dev dependency: npm install --save-dev typescript

gotcha CLI may not detect issues in files outside the given directory; does not follow imports or resolve monorepos. ↓

fix Run tool on each package directory separately or use a glob pattern if supported (currently not).

gotcha Tool reports false positives for patterns that React Compiler actually supports (e.g., certain useEffect dependencies). Always verify with the actual compiler. ↓

fix Cross-check with React Compiler's own validation. Contribute to the tool to refine rules.

breaking Breaking changes in 0.2.0: output format changed from plain text to JSON; API renamed from analyze to run. ↓

fix Update scripts parsing CLI output or switch to programmatic API with run().

Install

npm install react-compiler-check

yarn add react-compiler-check

pnpm add react-compiler-check

Imports

default (CLI)
wrong
```
react-compiler-check
```
correct
```
npx react-compiler-check ./src
```
CLI is the primary interface; no JS API exported yet.
require (CJS)
```
const check = require('react-compiler-check')
```
Uncommon; the package is designed for CLI use, but can be required programmatically. No default export, use check.run().
ESM import
wrong
```
import reactCompilerCheck from 'react-compiler-check'
```
correct
```
import { run } from 'react-compiler-check'
```
Named export `run` is available for programmatic use. Default export does not exist.

Quickstart

Scans all .js/.jsx/.ts/.tsx files in ./src for React Compiler incompatibilities and displays actionable diagnostics.

npx react-compiler-check ./src