Method scheduleNavigation

packages/router/src/router.ts:655–710

(
    rawUrl: UrlTree,
    source: NavigationTrigger,
    restoredState: RestoredState | null,
    extras: NavigationExtras,
    priorPromise?: {
      resolve: (result: boolean | PromiseLike<boolean>) => void;
      reject: (reason?: any) => void;
      promise: Promise<boolean>;
    },
  )

  }

  private scheduleNavigation(
    rawUrl: UrlTree,
    source: NavigationTrigger,
    restoredState: RestoredState | null,
    extras: NavigationExtras,
    priorPromise?: {
      resolve: (result: boolean | PromiseLike<boolean>) => void;
      reject: (reason?: any) => void;
      promise: Promise<boolean>;
    },
  ): Promise<boolean> {
    if (this.disposed) {
      return Promise.resolve(false);
    }

    let resolve: (result: boolean | PromiseLike<boolean>) => void;
    let reject: (reason?: any) => void;
    let promise: Promise<boolean>;
    if (priorPromise) {
      resolve = priorPromise.resolve;
      reject = priorPromise.reject;
      promise = priorPromise.promise;
    } else {
      promise = new Promise<boolean>((res, rej) => {
        resolve = res;
        reject = rej;
      });
    }

    // Indicate that the navigation is happening.
    const taskId = this.pendingTasks.add();
    afterNextNavigation(this, () => {
      // Remove pending task in a microtask to allow for cancelled
      // initial navigations and redirects within the same task.
      queueMicrotask(() => this.pendingTasks.remove(taskId));
    });

    this.navigationTransitions.handleNavigationRequest({
      source,
      restoredState,
      currentUrlTree: this.currentUrlTree,
      currentRawUrl: this.currentUrlTree,
      rawUrl,
      extras,
      resolve: resolve!,
      reject: reject!,
      promise,
      currentSnapshot: this.routerState.snapshot,
      currentRouterState: this.routerState,
    });

    // Make sure that the error is propagated even though `processNavigations` catch
    // handler does not rethrow
    // perf: Use `.bind` to avoid holding the other closures in this scope while this promise is unsettled.
    return promise.catch(Promise.reject.bind(Promise));
  }
}