microsoft/playwright · error · Error

Cannot fast-forward to the past

Error message

Cannot fast-forward to the past

What it means

Error "Cannot fast-forward to the past" thrown in microsoft/playwright.

Source

Thrown at packages/injected/src/clock.ts:286

    await this._innerPause();
    try {
      await fn();
    } finally {
      this._innerResume();
    }
  }

  async fastForward(ticks: number) {
    this._replayLogOnce();
    await this._runWithDisabledRealTimeSync(async () => {
      await this._innerFastForwardTo(shiftTicks(this._now.ticks, ticks | 0));
    });
  }

  private async _innerFastForwardTo(to: Ticks) {
    if (to < this._now.ticks)
      throw new Error('Cannot fast-forward to the past');
    for (const timer of this._timers.values()) {
      if (to > timer.callAt)
        timer.callAt = to;
    }
    await this._runTo(to);
  }

  addTimer(options: { func: TimerHandler, type: TimerType, delay?: number | string, args?: any[] }): number {
    this._replayLogOnce();

    if (options.type === TimerType.AnimationFrame && !options.func)
      throw new Error('Callback must be provided to requestAnimationFrame calls');
    if (options.type === TimerType.IdleCallback && !options.func)
      throw new Error('Callback must be provided to requestIdleCallback calls');
    if ([TimerType.Timeout, TimerType.Interval].includes(options.type) && !options.func && options.delay === undefined)
      throw new Error('Callback must be provided to timer calls');

    let delay = options.delay ? +options.delay : 0;

View on GitHub (pinned to c8fc3bf8d3)

When it happens

Trigger: Thrown at packages/injected/src/clock.ts:286 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/playwright@c8fc3bf8d3 (2026-08-12). Data as JSON: /api/errors/b0dccb39807679bd. Report an issue: GitHub.