README.md

Glance AppWidget Testing

GlanceScreenshotTestActivity

A simple activity to render a Glance composable without binding an appwidget for screenshot testing. It provides functions that can be called to initialize and render the Glance composable in it.

Setup

repositories {
    mavenCentral()
}

dependencies {
    debugImplementation "com.google.android.glance.tools:appwidget-testing:<version>"
}

Usage

Define an ActivityScenarioRule in your test class for the GlanceScreenshotTestActivity.

    @get:Rule
    val activityScenarioRule =
        ActivityScenarioRule(GlanceScreenshotTestActivity::class.java)

Initialize the size and state for your composable in the onActivity runner and provide the composable to be rendered in the GlanceScreenshotTestActivity.

activityScenarioRule.scenario.onActivity {
    it.setAppWidgetSize(size)
    it.setState(preferencesOf(myKey to 2))

    it.renderComposable {
        MyGlanceContent()
    }
}

Then, using screenshot testing tool of your choice capture and compare the screenshot of the activity. For example, following sample uses Roborazzi capture and verify the screenshot.

NOTE: The device and screenshot framework you use should support hardware acceleration and clipToOutline to see rounded corners. For robolectric, see this issue. When using an emulator, you may use Espresso's captureToBitmap to ensure that the corner radius is captured.

Espresso.onView(ViewMatchers.isRoot())
    .captureRoboImage(
        filePath = "src/test/resources/golden/$goldenFileName.png",
        roborazziOptions = RoborazziOptions(
            compareOptions = RoborazziOptions.CompareOptions(
                changeThreshold = 0F
            )
        )
    )

For a complete example, see SampleGlanceScreenshotTest.