5 TypeScript Tips Every Developer Should Know

1. Use Discriminated Unions

Discriminated unions make it easy to handle different states in your application:

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

2. Leverage satisfies Operator

The satisfies keyword lets you validate that an expression matches some type without widening it:

const config = {
  port: 3000,
  host: "localhost",
} satisfies Record<string, string | number>;

3. Use const Assertions

const assertions give you literal types:

const ROUTES = ["/", "/about", "/blog"] as const;
type Route = (typeof ROUTES)[number]; // "/" | "/about" | "/blog"

4. Template Literal Types

Build string types dynamically:

type EventName = `on${Capitalize<string>}`;

5. infer for Type Extraction

Extract types from complex structures:

type ElementType<T> = T extends Array<infer U> ? U : never;

These patterns will help you write more expressive and safer TypeScript code.