Re-exports

Often modules extend other modules, and partially expose some of their features. A re-export does not import it locally, or introduce a local variable.

ParseIntBasedZipCodeValidator.ts

export class ParseIntBasedZipCodeValidator {
  isAcceptable(s: string) {
    return s.length === 5 && parseInt(s).toString() === s;
  }
}

// Export original validator but rename it
export {ZipCodeValidator as RegExpBasedZipCodeValidator} from "./ZipCodeValidator";

Optionally, a module can wrap one or more modules and combine all their exports using export * from "module" syntax.

AllValidators.ts

export * from "./StringValidator"; // exports interface 'StringValidator'
export * from "./LettersOnlyValidator"; // exports class 'LettersOnlyValidator'
export * from "./ZipCodeValidator";  // exports class 'ZipCodeValidator'

Links:

https://www.typescriptlang.org/docs/handbook/modules.html#re-exports

doc_TypeScript

2025-01-10 15:47:30

Comments