This page provides troubleshooting help and answers to frequently asked questions about running tests with Firebase Test Lab. Known issues are also documented. If you can't find what you're looking for or need additional help, join the #test-lab channel on Firebase Slack or contact Firebase support.
Troubleshooting
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.
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:
- Check for known outages in the Firebase status dashboard.
Retry the test in Test Lab to verify that it is reproducible.
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.
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.
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).
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.
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.
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:
| Issue description | Possible resolution |
|---|---|
| Test case did not run because of a timeout. If the total duration of the tests is longer than a timeout you specified or longer than a max timeout, Test Lab cancels the rest of the test cases. |
|
| The test case failed to complete because it exited prematurely or got stuck. The test case may exit prematurely because of an uncaught exception or assertion error. Test cases can get stuck in an infinite loop or might be unable to proceed, for example, if the app does not show the correct view and the test case can't perform the action on the UI. |
Check the video and the logcat to investigate where the test
stopped.
|
A custom test runner (including extending AndroidJUnitRunner) crashed
unexpectedly or wrote unexpected test case start or end markers to
logcat.
|
Check your test runner code. |
Excessive logs were written to logcat, which overwhelmed the buffer
or crashed the logcat process.
|
Reduce writes to logcat.
|
| The app under test crashed. | Debug your app. |
Frequently asked questions
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.
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.
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.
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.
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.
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.
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.
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.
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.
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-statescommand on the foldable device.
Google Pixel Fold (model ID felix)
$ 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}, ]
Samsung Galaxy Z Fold4 (model ID q4q)
$ 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}, ]
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.
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.
Yes! Virtual devices are updated when the following changes are made:
- Updates to existing images
- Deprecation of earlier API levels
- New Android API levels are added
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
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
Known issues
Robo test cannot bypass sign-in screens that require additional user action beyond entering credentials to sign in, for example, completing a CAPTCHA.
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.