ts-patterns

Exhaustive type checking in TypeScript is best achieved using discriminated unions, which enforce literal preservation and ensure all possible union cases are handled. This pattern prevents unhandled states and improves runtime safety.

Use the satisfies operator in TypeScript to preserve literal types without widening them during assignment. It validates that an object conforms to a specific type while retaining the original literal values for stricter downstream inference.

Branded types are needed in TypeScript when you must distinguish structurally identical types, like a UserId and a ProductId string. They prevent accidental cross-assignment and enforce domain-specific type safety.

Yes, these TypeScript patterns apply to library and application code across Node, Deno, Bun, browser, and edge runtimes. They focus on strict configurations and type-level logic independent of the JavaScript runtime environment.

Configure an exports map in your package.json to define separate entry points for ESM and CJS dual publishing. This ensures consumers receive the correct module format based on their TypeScript runtime environment and module resolution settings.

Enabling strict mode by default in TypeScript catches implicit any types and null reference errors early. It forms the foundation for an inference-first API design that minimizes annotation burden and maximizes type safety.