spec/frontend/__mocks__/lodash/debounce.js


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// `lodash/debounce` has a non-trivial implementation which can lead to
// [flaky spec errors][1]. This mock simply makes `debounce` calls synchronous.
//
// In the future we could enhance this by injecting some test values in
// the function passed to it. See [this issue][2] for more information.
//
// [1]: https://gitlab.com/gitlab-org/gitlab/-/issues/212532
// [2]: https://gitlab.com/gitlab-org/gitlab/-/issues/213378
// Further reference: https://github.com/facebook/jest/issues/3465

export default (fn) => {
  const debouncedFn = jest.fn().mockImplementation(fn);
  debouncedFn.cancel = jest.fn();
  debouncedFn.flush = jest.fn().mockImplementation(() => {
    const errorMessage =
      "The .flush() method returned by lodash.debounce is not yet implemented/mocked by the mock in 'spec/frontend/__mocks__/lodash/debounce.js'.";

    throw new Error(errorMessage);
  });

  return debouncedFn;
};