Tree Shaking the Bytes Away

How does the way you write code impact your final bundle size? Learn two powerful techniques to make your JavaScript more tree-shakeable.

#1about 2 minutes

Understanding tree shaking to remove unused code

Tree shaking is a process used by bundlers to automatically remove unused code, also known as dead code, from your final application build.

#2about 4 minutes

How bundlers work and why they are necessary

Bundlers are essential for optimizing browser applications by combining code into a single file and enabling tree shaking, unlike native browser imports which load entire modules.

#3about 4 minutes

How static analysis enables code removal

Bundlers use static analysis at build time to create a dependency graph and identify unused code, but they cannot account for dynamic, runtime conditions.

#4about 3 minutes

How to test and measure tree shaking effectiveness

Use the `size-limit` NPM package to create test scenarios that measure bundle size impact and integrate these checks into CI to prevent regressions.

#5about 5 minutes

Using composition over options for better tree shaking

Refactor code from an options-based approach to a composition pattern to ensure optional features and their dependencies can be completely tree-shaken away.

#6about 4 minutes

Using static build flags for build-time optimization

Implement magic strings that are replaced with boolean values at build time, allowing the bundler to remove entire code blocks like debug logs for production builds.

#7about 4 minutes

Q&A on barrel files and build environment differences

The Q&A covers how barrel files can complicate tree shaking and the potential risks of having different development and production builds due to build-time flags.