TypeScript Best Practices

Pair with React Best Practices

When working with React components (.tsx, .jsx files or @react imports), always load react-best-practices alongside this skill. This skill covers TypeScript fundamentals; React-specific patterns (effects, hooks, refs, component design) are in the dedicated React skill.

Type-First Development

Types define the contract before implementation. Follow this workflow:

1. Define the data model - types, interfaces, and schemas first
2. Define function signatures - input/output types before logic
3. Implement to satisfy types - let the compiler guide completeness
4. Validate at boundaries - runtime checks where data enters the system

Make Illegal States Unrepresentable

Use the type system to prevent invalid states at compile time.