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Rstest
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      • Fake timers

      The fake timers may be useful when a piece of code sets a long timeout that we don't want to wait for in a test.

      Rstest provides some utility functions to help you fake timers powered by @sinonjs/fake-timers.

      rstest.useFakeTimers

      • Alias: rs.useFakeTimers
      • Type: (config?: FakeTimerInstallOpts) => Rstest

      To enable mocking timers, you need to call this method. It uses @sinonjs/fake-timers under the hood.

      rstest.useFakeTimers();

      You can also pass a configuration object to customize the behavior of the fake timers.

      rstest.useRealTimers

      • Alias: rs.useRealTimers
      • Type: () => Rstest

      Restores the original timer functions (such as setTimeout, setInterval, etc.), disabling the fake timers.

      rstest.useRealTimers();

      rstest.isFakeTimers

      • Alias: rs.isFakeTimers
      • Type: () => boolean

      Returns true if fake timers are currently enabled, otherwise false.

      if (rstest.isFakeTimers()) {
  // Fake timers are active
}

      rstest.setSystemTime

      • Alias: rs.setSystemTime
      • Type: (now?: number | Date) => Rstest

      Sets the current system time used by fake timers. Useful for testing code that depends on the current date or time.

      rstest.useFakeTimers();
rstest.setSystemTime(new Date('2020-01-01T00:00:00Z'));

      rstest.getRealSystemTime

      • Alias: rs.getRealSystemTime
      • Type: () => number

      Returns the real system time (as a timestamp), even when fake timers are enabled.

      const realTime = rstest.getRealSystemTime();

      rstest.runAllTicks

      • Alias: rs.runAllTicks
      • Type: () => Rstest

      Runs all queued microtasks (e.g., process.nextTick).

      rstest.runAllTimers

      • Alias: rs.runAllTimers
      • Type: () => Rstest

      Executes all pending timers (both timeouts and intervals).

      rstest.runAllTimersAsync

      • Alias: rs.runAllTimersAsync
      • Type: () => Promise<Rstest>

      Asynchronously executes all pending timers.

      rstest.runOnlyPendingTimers

      • Alias: rs.runOnlyPendingTimers
      • Type: () => Rstest

      Runs only the currently pending timers (does not schedule new ones).

      rstest.runOnlyPendingTimersAsync

      • Alias: rs.runOnlyPendingTimersAsync
      • Type: () => Promise<Rstest>

      Asynchronously runs only the currently pending timers.

      rstest.advanceTimersByTime

      • Alias: rs.advanceTimersByTime
      • Type: (ms: number) => Rstest

      Advances the fake timers by the specified milliseconds, executing any timers scheduled within that time.

      rstest.advanceTimersByTimeAsync

      • Alias: rs.advanceTimersByTimeAsync
      • Type: (ms: number) => Promise<Rstest>

      Asynchronously advances the fake timers by the specified milliseconds.

      rstest.advanceTimersToNextTimer

      • Alias: rs.advanceTimersToNextTimer
      • Type: (steps?: number) => Rstest

      Advances the timers to the next scheduled timer, optionally for a given number of steps.

      rstest.advanceTimersToNextTimerAsync

      • Alias: rs.advanceTimersToNextTimerAsync
      • Type: (steps?: number) => Promise<Rstest>

      Asynchronously advances the timers to the next scheduled timer.

      rstest.advanceTimersToNextFrame

      • Alias: rs.advanceTimersToNextFrame
      • Type: () => Rstest

      Advances the timers to the next animation frame.

      rstest.getTimerCount

      • Alias: rs.getTimerCount
      • Type: () => number

      Returns the number of fake timers still left to run.

      const count = rstest.getTimerCount();

      rstest.clearAllTimers

      • Alias: rs.clearAllTimers
      • Type: () => Rstest

      Removes all timers that are scheduled to run.

      rstest.clearAllTimers();