Write Modern JavaScript

Overview

TypeScript compiles to JavaScript, and the quality of that output depends on your target configuration and coding style. Write modern JavaScript (ES2020+) and let TypeScript handle compatibility through downleveling. Modern features often produce cleaner, more efficient code than manually implementing fallbacks.

Avoid TypeScript features that compile to verbose JavaScript when standard modern features exist.

When to Use This Skill

• Writing TypeScript that compiles to JavaScript
• Configuring tsconfig.json target
• Choosing which language features to use
• Supporting older browsers through compilation
• Optimizing bundle size

The Iron Rule

Write modern JavaScript (ES2020+) and let TypeScript downlevel for older environments. Prefer standard features over TypeScript-specific ones that compile to verbose code.