Function runInTestZone

packages/zone.js/lib/zone-spec/async-test.ts:270–333

(
      fn: Function,
      context: any,
      applyArgs: unknown[] | undefined,
      finishCallback: Function,
      failCallback: Function,
    )

    };

    function runInTestZone(
      fn: Function,
      context: any,
      applyArgs: unknown[] | undefined,
      finishCallback: Function,
      failCallback: Function,
    ) {
      const currentZone = Zone.current;
      const AsyncTestZoneSpec = (Zone as any)['AsyncTestZoneSpec'];
      if (AsyncTestZoneSpec === undefined) {
        throw new Error(
          'AsyncTestZoneSpec is needed for the async() test helper but could not be found. ' +
            'Please make sure that your environment includes zone.js/plugins/async-test',
        );
      }
      const ProxyZoneSpec = (Zone as any)['ProxyZoneSpec'] as {
        get(): {setDelegate(spec: ZoneSpec): void; getDelegate(): ZoneSpec};
        assertPresent: () => void;
      };
      if (!ProxyZoneSpec) {
        throw new Error(
          'ProxyZoneSpec is needed for the async() test helper but could not be found. ' +
            'Please make sure that your environment includes zone.js/plugins/proxy',
        );
      }
      const proxyZoneSpec = ProxyZoneSpec.get();
      ProxyZoneSpec.assertPresent();
      // We need to create the AsyncTestZoneSpec outside the ProxyZone.
      // If we do it in ProxyZone then we will get to infinite recursion.
      const proxyZone = Zone.current.getZoneWith('ProxyZoneSpec');
      const previousDelegate = proxyZoneSpec.getDelegate();
      proxyZone!.parent!.run(() => {
        const testZoneSpec: ZoneSpec = new AsyncTestZoneSpec(
          () => {
            // Need to restore the original zone.
            if (proxyZoneSpec.getDelegate() == testZoneSpec) {
              // Only reset the zone spec if it's
              // still this one. Otherwise, assume
              // it's OK.
              proxyZoneSpec.setDelegate(previousDelegate);
            }
            (testZoneSpec as any).unPatchPromiseForTest();
            currentZone.run(() => {
              finishCallback();
            });
          },
          (error: any) => {
            // Need to restore the original zone.
            if (proxyZoneSpec.getDelegate() == testZoneSpec) {
              // Only reset the zone spec if it's sill this one. Otherwise, assume it's OK.
              proxyZoneSpec.setDelegate(previousDelegate);
            }
            (testZoneSpec as any).unPatchPromiseForTest();
            currentZone.run(() => {
              failCallback(error);
            });
          },
          'test',