writing-bundler-tests

To test Bun's bundler behavior, you can use the itBundled test pattern with expectBundled.ts in the test/bundler suite to validate multi-file bundles, CJS/ESM interop, and dead-code elimination through deterministic assertions.

The itBundled pattern provides structured test templates and reusable expectations for validating Bun bundler output. It requires expectBundled.ts and structured file layouts in test/bundler to drive deterministic outcomes for single-file and multi-file bundles.

Set up CJS and ESM interop tests in Bun by adding a new test file under test/bundler/ and following itBundled examples to validate module interop scenarios. This approach uses structured file layouts to ensure deterministic bundle results.

Yes, you can check for dead-code elimination in Bun bundler tests by using itBundled patterns with expectBundled.ts. This provides deterministic assertions to verify that unused code is properly eliminated during the bundling process.

Testing Bun's bundler requires using expectBundled.ts from the test/bundler directory. The itBundled pattern relies on structured file layouts and this specific test helper to validate single-file and multi-file bundling scenarios deterministically.

Bun bundler tests become brittle and verbose without structured patterns. Using itBundled with expectBundled.ts provides reusable test templates and deterministic assertions for output, errors, and bundle results, streamlining the validation process.