TypeScript Best Practices

TypeScript shines brightest in large codebases where type safety prevents entire categories of bugs. But scaling TypeScript requires intentional practices.

Strict Mode Always

Enable strict mode from day one. The additional type checking catches subtle bugs early and forces you to think carefully about your data structures.

// tsconfig.json
{
  "compilerOptions": {
    "strict": true
  }
}

Discriminated Unions

Use discriminated unions to model state that can take different forms:

type Result =
  | { status: "loading" }
  | { status: "success"; data: T }
  | { status: "error"; message: string };

Utility Types

Leverage TypeScript's built-in utility types like Partial, Pick, and Omit to derive new types from existing ones.

Branded Types

Use branded types to distinguish between values that share the same underlying type but represent different concepts, like UserId vs ProductId.