Configuring Testify to run on Gradle managed device

Starting from API levels 27 Android Gradle Plugin allows you to configure virtual test devices in your project's Gradle files . This feature improves testing experience by delegating the task of starting, shutting down and managing emulator to the Gradle.

When using Gradle managed device user must use Test storage service to save screenshots. Using this service Android Gradle Plugin would be able to save test output including screenshots and diffs to the build folder

Adding Gradle managed device configuration to build file

To create new Gradle managed device add it's definition to the build.gradle file:

android {
    testOptions {
        managedDevices {
            devices {
                NAME_OF_THE_DEVICE(com.android.build.api.dsl.ManagedVirtualDevice) {
                    device = "Pixel 2"
                    apiLevel = 30
                    systemImageSource = "aosp"
                }
            }
        }
    }
}

In order to receive screenshots after test execution enable TestStorageService:

android {
    defaultConfig {
        testInstrumentationRunnerArguments useTestStorageService: "true"
    }
}

dependencies {
    androidTestUtil("androidx.test.services:test-services:1.4.2")
}

With that changes applied couple of new Gradle tasks should be added to your project. Suppose, you named your device tester, then testerCheck and testDebugAndroidTest tasks should be added to your project.

Configuring the Testify library

You also need to instruct Testify to use Test storage to store screenshots and diffs. This could be done using Testify plugin configuration:

testify {
    useTestStorage = true
}

Running screenshot tests

To perform screenshot test verification run any of the new Gradle tasks, for example ./gradlew testerDebugAndroidTest.

Because we need to run specific Gradle task to execute our tests using Gradle managed device, we cannot use screenshotPull task. When execution completed go to the module's build/outputs/managed_device_android_test_additional_output/tester folder to get recorded screenshots or diffs.

Updating baselines

Because we need to run specific Gradle task to execute our tests using Gradle managed device, we cannot use screenshotRecord task. To generate new baseline there are two options:

• apply necessary setting to the ScreenshotRule:

@get:Rule
var rule = ScreenshotRule(ClientListActivity::class.java)

@ScreenshotInstrumentation
@Test
fun testMissingBaseline() {
    rule
        .setRecordModeEnabled(true)
        .assertSame()
}

• or enable record mode in the build.gradle file:

testify {
    recordMode = true
}

Again we cannot use screenshotPull task. When execution completed go to the module's build/outputs/managed_device_android_test_additional_output/tester and copy recorded baseline into the androidTest/assets/screenshots/ directory, for example: androidTest/assets/screenshots/30-1080x1920@420dp-en_US

Sample

Please check provided sample .