Tree Shaking

Summary

A build-time optimization that removes unused exports from your final bundle, based on static analysis of your `import`/`export` statements.

• 1Import only one function from a large utility library and confirm the whole library isn't bundled.
• 2Learn why tree shaking requires ES modules (`import`/`export`), not CommonJS (`require`).
• 3Check a library's `package.json` for a `sideEffects` field, which affects tree shaking.