typescript-fp

Type-safe functional programming in TypeScript enforces strict typing and functional patterns using tools like fp-ts, discriminated unions, and pipe/flow composition. Configure strict tsconfig.json settings, apply ESLint rules for functional style, and use advanced type utilities like DeepReadonly to ensure pure, immutable code with explicit error handling.

Monadic patterns like Option and Either provide safer error handling by encoding success and failure cases in the type system. In TypeScript, they let you chain operations with pipe composition while preserving type safety, avoiding null checks and unhandled exceptions through explicit, composable error paths.

Pipe and flow composition in TypeScript chains functions left-to-right while preserving type signatures at each step. Use fp-ts or similar functional libraries to ensure the output type of each function matches the input type of the next, preventing runtime type errors and enabling IDE autocomplete.

Discriminated unions work with functional patterns to create exhaustive, type-safe case handling. Combined with monadic composition and pipe utilities, they enable you to model domain logic as tagged variants that the type system enforces, eliminating invalid state combinations.

Advanced type utilities like ReturnTypeOf, Union-to-Intersection, and DeepReadonly enable functional programming patterns by extracting types from functions, combining union members, and enforcing immutability. These utilities integrate with fp-ts and strict tsconfig settings to deliver compile-time guarantees.