typescript-utility-types

TypeScript utility types like Pick, Omit, Partial, and Required enable compile-time type transformation. Use Pick to select specific properties, Omit to exclude sensitive fields, Partial to make properties optional, and Required to enforce all properties. These utilities resolve type-safety gaps by deriving new types from existing ones without runtime overhead.

Mapped types iterate over object keys to transform properties systematically—use them to create Readonly versions or convert property types. Conditional types use ternary logic to branch type resolution based on constraints—use them with Extract and Exclude for selective type filtering. Both enable advanced type manipulation for complex data models.

Use ReturnType to extract a function's return type and Parameters to capture its parameter list as a tuple. These utility types inspect callable signatures at compile time, enabling you to reuse function shapes across APIs, callbacks, and type-safe wrappers without manually duplicating type definitions.

Yes. Use the Readonly utility type or mapped types with readonly modifiers to enforce immutability on object properties. This prevents accidental mutations in API responses and configuration objects, improving type safety across your TypeScript project and catching modification attempts at compile time.

Use Record when you need a simple key-value type with uniform value types—ideal for configuration objects and lookup tables. Use mapped types for more complex transformations where properties need conditional logic, custom key mapping, or property-specific modifiers. Mapped types offer flexibility; Record prioritizes clarity for straightforward schemas.