rxjs/src/internal/scheduler/AsapScheduler.ts

Reactive Extensions for modern JavaScript

import { AsyncAction } from './AsyncAction';
import { AsyncScheduler } from './AsyncScheduler';

export class AsapScheduler extends AsyncScheduler {
  public flush(action?: AsyncAction<any>): void {
    this._active = true;
    this._scheduled = undefined;

    const { actions } = this;
    let error: any;
    let index = -1;
    action = action || actions.shift()!;
    const count = actions.length;

    do {
      if ((error = action.execute(action.state, action.delay))) {
        break;
      }
    } while (++index < count && (action = actions.shift()));

    this._active = false;

    if (error) {
      while (++index < count && (action = actions.shift())) {
        action.unsubscribe();
      }
      throw error;
    }
  }
}