Detox Test Flakiness

[jchan29]

Hi all, our team is experiencing flakiness when running our detox tests (which only includes a test that verifies a login user flow) locally. The detox server unexpectedly loses connection with our Android emulator and sometimes is unable to connect to our test app. At times, we also get errors about insufficient storage. We're open to any suggestions and resources you can share.

On consecutive runs, the errors are inconsistent and include:

The app has unexpectedly disconnected from Detox server.

  1 | /* eslint-disable no-undef*/
  2 | beforeAll(async () => {
> 3 |   await device.launchApp();
    |                ^
  4 |   await device.setURLBlacklist(['.*pndsn.com/v2/subscribe.*']);
  5 | });
  6 | 

The app has unexpectedly disconnected from Detox server.

  15 |       .toBeVisible()
  16 |       .withTimeout(500);
> 17 |     await element(by.text('Provider')).tap();

detox[64196] INFO:  [APP_STATUS] App synchronization debug: The app appears to be idle!

detox[64196] INFO:  [APP_STATUS] App synchronization debug: 
The app is busy, due to: 
	 - Enqueued timers
detox[64196] WARN:  [PENDING_REQUESTS] The app has not responded to the network requests below:
  (id = 2) invoke: {"target":{"type":"Class","value":"com.wix.detox.espresso.EspressoDetox"},"method":"perform","args":[{"type":"Invocation","value":{"target":{"type":"Class","value":"androidx.test.espresso.Espresso"},"method":"onView","args":[{"type":"Invocation","value":{"target":{"type":"Class","value":"com.wix.detox.espresso.DetoxMatcher"},"method":"matcherForContentDescription","args":["login_info_text"]}}]}},{"type":"Invocation","value":{"target":{"type":"Class","value":"com.wix.detox.espresso.DetoxViewActions"},"method":"click","args":[]}}]}

That might be the reason why the test "Auth test should login to the app" has timed out.

detox[59663] ERROR: [EXEC_FAIL, #45] Failure [INSTALL_FAILED_INSUFFICIENT_STORAGE]

    DetoxRuntimeError: Detox can't seem to connect to the test app(s)!

    HINT: 

    Have you forgotten to call 'device.launchApp()' in the beginning of your test?
    Refer to our troubleshooting guide, for full details: https://github.com/wix/Detox/blob/master/docs/Troubleshooting.RunningTests.md#tests-execution-hangs

    ---
    The following package could not be delivered:

    {
      type: 'reactNativeReload',
      params: {},
      messageId: -1000
    }

       6 | 
       7 | beforeEach(async () => {
    >  8 |   await device.reloadReactNative();
         |                ^
       9 | });
      10 | 

    Test Failed: 'at least 75 percent of the view's area is displayed to the user.' doesn't match the selected view.
    Expected: at least 75 percent of the view's area is displayed to the user.
         Got: null