Function waitForAsync

packages/core/testing/src/async.ts:25–45

(fn: Function)

 * @publicApi
 */
export function waitForAsync(fn: Function): (done: any) => any {
  const _Zone: any = typeof Zone !== 'undefined' ? Zone : null;
  if (!_Zone) {
    return function () {
      return Promise.reject(
        'Zone is needed for the waitForAsync() test helper but could not be found. ' +
          'Please make sure that your environment includes zone.js',
      );
    };
  }
  const asyncTest = _Zone && _Zone[_Zone.__symbol__('asyncTest')];
  if (typeof asyncTest === 'function') {
    return asyncTest(fn);
  }
  return function () {
    return Promise.reject(
      'zone-testing.js is needed for the async() test helper but could not be found. ' +
        'Please make sure that your environment includes zone.js/testing',
    );
  };
}