Function withProxyZone

packages/zone.js/lib/zone-spec/fake-async-test.ts:1075–1089

(fn: T)

 * @experimental
 */
export function withProxyZone<T extends Function>(fn: T): T {
  const autoProxyFn: any = function (this: unknown, ...args: any[]) {
    const proxyZoneSpec = getProxyZoneSpec();
    if (proxyZoneSpec === undefined) {
      throw new Error(
        'ProxyZoneSpec is needed for the withProxyZone() test helper but could not be found. ' +
          'Make sure that your environment includes zone-testing.js',
      );
    }

    const proxyZone = proxyZoneSpec.get() !== undefined ? Zone.current : getOrCreateRootProxy();
    return proxyZone.run(fn, this, args);
  };
  return autoProxyFn as T;
}

function getOrCreateRootProxy() {
  const ProxyZoneSpec = getProxyZoneSpec();