liberal-accept-strict-return

To design TypeScript APIs with flexible inputs and strict output, you broaden the accepted input types for multi-form or optional fields while constraining the return type to a single, precise canonical structure.

Postel's Law in TypeScript function signatures means accepting varied or optional input arguments from callers while returning a single, well-defined output structure to predictably simplify downstream data consumption.

Use liberal input and strict output patterns in API design when creating function signatures or data models where callers may provide varied inputs but require a predictable, canonical result format for downstream correctness.

Yes, you can apply liberal input strict output patterns to TypeScript library design by allowing broader input types for ease of use while returning fixed, precise output formats to improve usability without sacrificing downstream correctness.

Returning a canonical output type from TypeScript functions with optional inputs simplifies consumption by ensuring downstream code always receives a single, well-defined structure, preventing type checking errors and reducing complexity.

The main limitation of accepting multi-form inputs in TypeScript APIs is the increased internal complexity required to normalize varied formats into a single precise output, requiring clear separation between input flexibility and output specificity.