test

Run tests for the React codebase.

Arguments:

$ARGUMENTS: Channel, flags, and test pattern

Usage Examples:

/test ReactFiberHooks - Run with source channel (default) /test experimental ReactFiberHooks - Run with experimental channel /test www ReactFiberHooks - Run with www-modern channel /test www variant false ReactFiberHooks - Test VARIANT=false /test stable ReactFiberHooks - Run with stable channel /test classic ReactFiberHooks - Run with www-classic channel /test watch ReactFiberHooks - Run in watch mode (TDD)

Release Channels:

(default) - Source/canary channel, uses ReactFeatureFlags.js defaults experimental - Source/experimental channel with EXPERIMENTAL flags = true www - www-modern channel with VARIANT flags = true www variant false - www channel with VARIANT flags = false stable - What ships to npm classic - Legacy www-classic (rarely needed)

Instructions:

Parse channel from arguments (default: source) Map to yarn command: (default) → yarn test --silent --no-watchman experimental → yarn test -r=experimental --silent --no-watchman stable → yarn test-stable --silent --no-watchman classic → yarn test-classic --silent --no-watchman www → yarn test-www --silent --no-watchman www variant false → yarn test-www --variant=false --silent --no-watchman Report test results and any failures

Hard Rules:

Use --silent to see failures - This limits the test output to only failures. Use --no-watchman - This is a common failure in sandboxing.

Common Mistakes:

Running without a pattern - Runs ALL tests, very slow. Always specify a pattern. Forgetting both www variants - Test www AND www variant false for VARIANT flags. Test skipped unexpectedly - Check for @gate pragma; see feature-flags skill.