Troubleshooting Espresso Test Error: AppNotIdleException

Troubleshooting Espresso Test Error: AppNotIdleException

11 April 2024 Stephan Petzl Leave a comment Tech-Help

When conducting automated testing with Espresso, encountering an AppNotIdleException can be a frustrating experience. This exception indicates that Espresso has looped for an extended period while waiting for the application to be idle, but has failed to detect an idle state. If you’re facing this issue even after disabling animations in the developer options, this guide will help you identify and resolve the problem.

Understanding the AppNotIdleException

The AppNotIdleException occurs when Espresso waits for the application to reach an idle state but is unable to do so within a certain timeframe. This can be due to background tasks, animations, or any ongoing processes that prevent the app from being idle.

Identifying the Cause

To pinpoint what’s causing the exception, you can use a method to dump the current state of all active threads at the time of the exception. This technique can reveal which processes are still running and potentially interfering with Espresso’s ability to recognize an idle state.

Example Method to Dump Active Threads:

private void dumpThreads() {
    int activeCount = Thread.activeCount();
    Thread[] threads = new Thread[activeCount];
    for (Thread thread : threads) {
        System.err.println(thread.getName() + ": " + thread.getState());
        for (StackTraceElement stackTraceElement : thread.getStackTrace()) {
            System.err.println("\t" + stackTraceElement);

By implementing the above method, you can identify the “violators” that are using resources, such as the AsyncTask thread pool, which may be preventing the app from becoming idle.

Common Culprits and Solutions

Some known issues that can cause the AppNotIdleException include:

  • Third-party SDKs that perform background operations.
  • Animations, particularly on older Android versions, that are set to repeat indefinitely.
  • Components like SwipeRefreshLayout that may animate indefinitely due to bugs.

Handling Animations

For animations that are causing the issue, a workaround is to check if animations are enabled and, if not, prevent the animation from starting. This is particularly useful for older Android versions where animations may not autostart.

Example Method to Control Animation:

private fun startIconAnimation(imageView: ImageView) {
    if (areAnimationsEnabled()) {
        (imageView.drawable as Animatable).start()

private fun areAnimationsEnabled(): Boolean {
    val animatorDurationScale = Settings.Global.getFloat(
    return animatorDurationScale != 0.0f

If you’re working with API level 26 or higher, you can also use the ValueAnimator.areAnimatorsEnabled() method to check if animations are enabled.


Resolving an AppNotIdleException in Espresso tests requires a bit of detective work to identify the root cause. By examining active threads and handling known issues such as animations and third-party SDK operations, you can guide Espresso to correctly identify when your app is idle and proceed with the testing process.

Remember, while the solutions provided here can help address the immediate problem, it’s important to also consider the broader implications of these workarounds on your app’s behavior and performance.

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