TS code samples

destructured-jest.ts

/**
 * Jest tests can be destructured. However it won't work with inlineSnapshots
 */

const thrower = () => {
  throw new Error('test');
};
const simple = () => {
  //
};

test('#baseDefinition', () => {
  let t = true;
  const { not, toThrow } = expect(() => (t ? thrower() : simple()));
  toThrow();
  t = false;
  not.toThrow();
});

samples.ts

// Replace return type

/**
 * Helper for retrieving the argument type of a function
 */
export type ArgumentTypes<T> = T extends (...args: Array<infer U>) => any ? U : never;

  
/**
* Replace that argument type
*/
type ReplaceReturnType<T, TNewReturn> = (...a: ArgumentTypes<T>) => TNewReturn;