/tree-shake - Optimize Tree Shaking

Improve tree shaking effectiveness to reduce bundle size.

Steps

1. Analyze the current build configuration for tree shaking settings
2. Check package.json for sideEffects field configuration
3. Identify imports that prevent tree shaking: namespace imports, CommonJS requires
4. Find barrel files (index.ts re-exports) that bundle entire modules
5. Check for packages that do not support tree shaking (no ES modules)
6. Convert namespace imports to named imports where possible
7. Add sideEffects: false to package.json if all modules are pure
8. Configure the bundler to mark specific files as side-effect-free
9. Replace non-tree-shakeable packages with tree-shakeable alternatives
10. Split barrel files into direct imports for large modules
11. Rebuild and measure the size difference
12. Report: modules eliminated, size reduction, remaining issues

Rules

• Never mark files with side effects as side-effect-free
• Verify that tree shaking does not remove needed code
• Prefer named imports over namespace imports for better tree shaking
• Check that all internal packages have proper ESM exports
• Do not break the public API of packages when restructuring exports
• Test the application thoroughly after tree shaking changes
• Document any sideEffects configuration with comments explaining why