Test Lab troubleshooting & FAQ

Why is my test taking so long to run?

When you select a device with a high capacity level in the Test Lab catalog, tests may start faster. When a device has low capacity, tests might take longer to run. If the number of tests invoked is much larger than the capacity of the selected devices, tests can take longer to finish.

Tests running on any level device capacity level may take longer due to the following factors:

• Traffic, which affects device availability and test speed.
• Device or infrastructure failures, which can happen at any time. To check if there is a reported infrastructure for Test Lab, see the Firebase status dashboard.

To learn more about device capacity in Test Lab, see device capacity information for Android and iOS.

Why am I receiving inconclusive test results?

Inconclusive test outcomes commonly occur either because of canceled test runs or infrastructure errors.

Infrastructure errors are caused by internal Test Lab issues, like network errors or unexpected device behaviors. Test Lab internally retires test runs that produce infrastructure errors multiple times before reporting an inconclusive outcome; however, you can disable these retries using failFast.

To determine the cause of the error, follow these steps:

1. Check for known outages in the Firebase status dashboard.

2. Retry the test in Test Lab to verify that it is reproducible.

3. Try running the test on a different device or device type, if applicable.

If the issue persists, contact the Test Lab team in the #test-lab channel on Firebase Slack.

Why did sharding make my tests run longer?

Sharding can cause your tests to run longer when the number of shards you specified exceeds the number of devices available for use in Test Lab. To avoid this situation, try switching to a different device. For more information about choosing a different device, see Device Capacity.

Why is it taking a long time for my test to start?

When you submit a test request, your app is first validated, re-signed, etc. in preparation for running tests on a device. Normally, this process completes in less than a few seconds, but it can be affected by factors like the size of your app.

After your app is prepared, test executions are scheduled and remain in a queue until a device is ready to run it. Until all test executions finish running, the matrix status will be "Pending" (regardless of whether test executions are in the queue or actively running).

Why is it taking a long time for my test to finish?

After the test execution is finished, test artifacts are downloaded from the device, processed, and uploaded to Cloud Storage. The duration of this step can be affected by the amount and size of the artifacts.

App not returning data and can't locate screenshots

Test execution artifacts (such as screenshots and log files) are stored in Google Cloud Storage and directly rendered into the Firebase console. If your test execution was performed within the last 90 days, check that you have assigned project level roles (project owner, project editor, or project viewer). Please also make sure that Cloud Audit Logging is not enabled for your project or your organization.

If the execution was performed more than 90 days ago, most likely the test artifacts have been automatically deleted. You can check the result bucket configuration by clicking the Test results tab in the Test Lab dashboard. The default result bucket is configured to retain objects for 90 days.

To retain your test artifacts longer, run the command gcloud firebase test android run with the flag --results-bucket and pass in the name of the result bucket. For more information, visit the gcloud firebase test android run reference documentation.

Why am I receiving partial or missing instrumentation test case results?

When you run instrumentation tests, you might see test errors indicating partial results that contain messaging like Test run failed to complete. Expected x tests, received y (where y is less than x). This error means that Test Lab could not parse the logcat for test case start or end markers that are usually generated by AndroidJUnitRunner.

The following are common causes of this issue:

What are the no-cost quotas for Test Lab? What should I do if I run out?

Firebase Test Lab offers no-cost quotas for testing on devices and for using Cloud APIs. Note that the testing quota uses the standard Firebase pricing plan, while the Cloud API quotas do not.

• Testing quota

  Testing quotas are determined by the number of devices used to run tests. The Firebase Spark plan has a fixed testing quota at no cost to users. For the Blaze plan, your quotas might increase if your usage of Google Cloud increases over time. If you reach your testing quota, wait until the next day or upgrade to the Blaze plan if you are currently on the Spark plan. If you are already on the Blaze plan, you can request a quota increase. For more information, see Testing quota.

  You can monitor your testing quota usage in the Google Cloud console.

• Cloud Testing API quota

  The Cloud Testing API comes with two quota limits: requests per day per project, and requests per every 100 seconds per project. You can monitor your usage in the Google Cloud console.

• Cloud Tool Results API quota

  The Cloud Tool Results API comes with two quota limits: queries per day per project, and queries per every 100 seconds per project. You can monitor your usage in the Google Cloud console.

  Refer to Cloud API quotas for Test Lab for more information on API limits. If you've reached an API quota:

  • Submit a request for higher quotas by editing your quotas directly in the Google Cloud console (note that most limits are set to maximum by default), or

  • Request higher API quotas by filling out a request form in the Google Cloud console or by contacting Firebase support.

How do I find out if the traffic reaching my backend is coming from Test Lab?

From your backend, you can determine if traffic is coming from Firebase-hosted test devices by checking the source IP address against our IP ranges.

Does Test Lab work with VPC-SC?

Test Lab does not work with VPC-SC, which blocks the copying of apps and other test artifacts between Test Lab's internal storage and users' results buckets.

How do I detect flaky tests in Test Lab?

To detect flaky behavior in your tests, we recommend using the --num-flaky-test-attempts option. Deflake reruns are billed or counted toward your daily quota the same as normal test executions.

Keep the following in mind:

• The entire test execution runs again when a failure is detected. There’s no support for retrying only failed test cases.
• Deflake retry runs are scheduled to run at the same time, but are not guaranteed to run in parallel, for example, when traffic exceeds the number of available devices.

Does Test Lab support Appium, Flutter/FlutterDriver, ReactNative/Jest, or Cucumber?

While some of these items are on our roadmap, we're currently unable to provide commitment to supporting these testing and app development platforms.

Where can I find device details, like resolution, etc.?

Detailed device information is available through the API and can be accessed from the gcloud client using the describe command:

gcloud firebase test ios models describe MODEL

Can I use sharding with iOS tests?

Sharding isn't natively supported within Test Lab for iOS. However, you can use the Flank client to shard iOS test cases.

This works by setting OnlyTestIdentifiers key and values in .xctestrun file. See man page for xcodebuild.xctestrun for more details.

Why is my iOS test missing videos in the results?

For iOS 18 or later, we are not able to support videos in the results.

Does Test Lab support wearable devices?

Yes! Test Lab supports Google Pixel Watch. You can now run tests on your standalone Wear app on Google Pixel Watches. To learn more about Test Lab devices, see Test on available devices.

Does Test Lab support the latest Google devices?

Yes! Test Lab supports the Google Pixel Tablet and Google Pixel Fold. You can run your tests on your standalone physical devices. To learn more about Test Lab devices, see Test on available devices.

How do I detect a running test in Test Lab?

If you're testing your app in Firebase or running tests for a pre-launch report in the Play Console, you can detect whether a test is being run on a Firebase-hosted device by checking for the system property firebase.test.lab in your MainActivity file. You can then execute additional statements based on the boolean value for testLabSetting. For more information, see Modified test behaviors.

Does Test Lab support Appium, Flutter/FlutterDriver, ReactNative/Jest, or Cucumber?

While some of these items are on our roadmap, we're currently unable to provide commitment to supporting these testing and app development platforms. However, if you built your app with a framework that supports Espresso (for example, Flutter), you can write an instrumentation test using Espresso and then run the test in Test Lab.

Does Test Lab support testing obfuscated apps, for example, with ProGuard or R8)?

Test Lab does not explicitly support for obfuscation or deobfuscation. While the app will likely run, any obfuscated app data, like stack traces, will appear as obfuscated in the logs.

Can I use my foldable device in different foldable states and postures while testing on Test Lab?

Yes! You can test your foldable device in foldable states and postures.

Foldable devices can be in various folded states, such as FLAT (fully open) or HALF_OPENED (between fully open and completely closed).

Postures, on the other hand, consist of specific device orientation and foldable state. For example, tabletop posture, which is a HALF_OPENED state in horizontal orientation, or book posture, which is a HALF_OPENED state in vertical orientation.

If you are running instrumentation tests, you can use Jetpack WindowManager library and follow testing your app on foldables documentation to test on different states and postures.

Alternatively, available states are device-specific and can be interacted with using the adb shell command cmd device_state.

• To list the current state, run adb shell cmd device_state state.
• To set or override the current state, run adb shell cmd device_state state <IDENTIFIER>.
• To reset the state, run adb shell cmd device_state state reset.
• To check available states, run the adb shell cmd device_state print-states command on the foldable device.

$ adb shell cmd device_state print-states
Supported states: [
    DeviceState{identifier=0, name='CLOSED', app_accessible=true},
    DeviceState{identifier=1, name='HALF_OPENED', app_accessible=true},
    DeviceState{identifier=2, name='OPENED', app_accessible=true},
    DeviceState{identifier=3, name='REAR_DISPLAY_STATE', app_accessible=true},
]

$ adb shell cmd device_state print-states
Supported states: [
    DeviceState{identifier=0, name='CLOSE', app_accessible=true},
    DeviceState{identifier=1, name='TENT', app_accessible=true},
    DeviceState{identifier=2, name='HALF_FOLDED', app_accessible=true},
    DeviceState{identifier=3, name='OPEN', app_accessible=true},
]

Can I try out Test Lab if I don't have an app?

Unlike other Firebase products, you do not need to add a Firebase SDK in order to use Test Lab. If you don't already have an app, you can download an APK online or build an app and a test APK from one of the samples in the AndroidX GitHub repository. Note that you only need your app's APK file to run a Robo test, while an instrumentation test requires both an app and a test APK that are built from source code. For more information, read about Instrumented tests.

To learn more about Test Lab features, see Get started testing for Android with Firebase Test Lab.

What devices are best for screenshot-diff testing?

Screenshot-diff testing is where test assertions are based on comparing screen images obtained while running a test to golden images representing expected behavior. Such tests may be more brittle on some device types than others. We recommend targeting Arm (*.arm) emulator devices for these kinds of tests. Arm emulator devices use images that are very similar or identical to Android Studio ‘generic’ emulators.

We also recommend that you investigate test libraries that can help make screenshot tests more robust in the presence of expected changes.

Does Test Lab update virtual devices?

Yes! Virtual devices are updated when the following changes are made:

1. Updates to existing images
2. Deprecation of earlier API levels
3. New Android API levels are added

How do I enable coverage reports?

To enable coverage reports, add coverage=true to environmentVariables field. If you're using Android Test Orchestrator, you'll need to provide a directory to store the coverage results:

--environment-variables coverage=true,coverageFilePath=/sdcard/Download/

If you're not using Orchestrator, you can specify a file path:

--environment-variables coverage=true,coverageFile=/sdcard/Download/coverage.ec

Where can I find device details, like resolution, supported ABIs, etc.?

Detailed device information is available through the API and can be accessed from the gcloud client using the describe command:

gcloud firebase test android models describe MODEL

Sign-in Captchas

Robo test cannot bypass sign-in screens that require additional user action beyond entering credentials to sign in, for example, completing a CAPTCHA.

Automatic sign in

Automatically signing in with a Google account is not supported on Robo tests for iOS+ (Beta).

UI framework support

Robo test works best with apps that use UI elements from the Android UI framework (including View, ViewGroup, and WebView objects). If you use Robo test to exercise apps that use other UI frameworks, including apps that use the Unity game engine, the test may exit without exploring beyond the first screen.