Class ZoneImpl

packages/zone.js/lib/zone-impl.ts:785–1096

  mark('Zone');

  class ZoneImpl implements AmbientZone {
    static __symbol__: (name: string) => string = __symbol__;

    static assertZonePatched() {
      if (global['Promise'] !== patches['ZoneAwarePromise']) {
        throw new Error(
          'Zone.js has detected that ZoneAwarePromise `(window|global).Promise` ' +
            'has been overwritten.\n' +
            'Most likely cause is that a Promise polyfill has been loaded ' +
            'after Zone.js (Polyfilling Promise api is not necessary when zone.js is loaded. ' +
            'If you must load one, do so before loading zone.js.)',
        );
      }
    }

    static get root(): AmbientZone {
      let zone = ZoneImpl.current;
      while (zone.parent) {
        zone = zone.parent;
      }
      return zone;
    }

    static get current(): AmbientZone {
      return _currentZoneFrame.zone;
    }

    static get currentTask(): Task | null {
      return _currentTask;
    }

    static __load_patch(name: string, fn: PatchFn, ignoreDuplicate = false): void {
      if (Object.hasOwn(patches, name)) {
        // `checkDuplicate` option is defined from global variable
        // so it works for all modules.
        // `ignoreDuplicate` can work for the specified module
        const checkDuplicate = global[__symbol__('forceDuplicateZoneCheck')] === true;
        if (!ignoreDuplicate && checkDuplicate) {
          throw Error('Already loaded patch: ' + name);
        }
      } else if (!global['__Zone_disable_' + name]) {
        const perfName = 'Zone:' + name;
        mark(perfName);
        patches[name] = fn(global, ZoneImpl, _api);
        performanceMeasure(perfName, perfName);
      }
    }

    public get parent(): AmbientZone | null {
      return this._parent;
    }

    public get name(): string {
      return this._name;
    }

    private _parent: ZoneImpl | null;
    private _name: string;