Test your Compose layout

Test your app's UI to verify that behavior of your Compose code is correct. This lets you catch errors early and improve the quality of your app.

Compose provides a set of testing APIs to find elements, verify their attributes, and perform user actions. The APIs also include advanced features such as time manipulation. Use these APIs to create robust tests that verify your app's behavior.

Views

If you are working with views instead of Compose, see the general Test apps on Android section.

In particular, a good place to start is the Automate UI tests guide. It lays out how you can automate tests that run on-device, including when using views.

Key Concepts

The following are some key concepts for testing your Compose code.

Semantics: Compose tests interact with the UI using semantics, which give meaning to pieces of the UI and are generated alongside the UI hierarchy.
Testing APIs: Compose provides testing APIs for finding elements, making assertions on their state and properties, and performing actions to simulate user interactions.
Synchronization: By default, Compose tests automatically synchronize with the UI, waiting for it to be idle before making assertions or performing actions.
Interoperability: In hybrid apps, tests can interact seamlessly with both Compose and View-based elements, and integrate with other testing frameworks.

Testing cheatsheet

See the testing cheatsheet for an overview of all the key topics you should learn about testing in Compose.

Setup

Set up your app to let you test compose code.

First, add the following dependencies to the build.gradle file of the module containing your UI tests:

// Test rules and transitive dependencies:
androidTestImplementation("androidx.compose.ui:ui-test-junit4:$compose_version")
// Needed for createComposeRule(), but not for createAndroidComposeRule<YourActivity>():
debugImplementation("androidx.compose.ui:ui-test-manifest:$compose_version")

This module includes a ComposeTestRule and an implementation for Android called AndroidComposeTestRule. Through this rule you can set Compose content or access the activity. You construct the rules using factory functions, either createComposeRule or, if you need access to an activity, createAndroidComposeRule. A typical UI test for Compose looks like this:

// file: app/src/androidTest/java/com/package/MyComposeTest.kt

class MyComposeTest {

    @get:Rule val composeTestRule = createComposeRule()
    // use createAndroidComposeRule<YourActivity>() if you need access to
    // an activity

    @Test
    fun myTest() {
        // Start the app
        composeTestRule.setContent {
            MyAppTheme {
                MainScreen(uiState = fakeUiState, /*...*/)
            }
        }

        composeTestRule.onNodeWithText("Continue").performClick()

        composeTestRule.onNodeWithText("Welcome").assertIsDisplayed()
    }
}

Additional Resources

Test apps on Android: The main Android testing landing page provides a broader view of testing fundamentals and techniques.
Fundamentals of testing: Learn more about the core concepts behind testing an Android app.
Local tests: You can run some tests locally, on your own workstation.
Instrumented tests: It is good practice to also run instrumented tests. That is, tests that run directly on-device.
Continuous integration: Continuous integration lets you integrate your tests into your deployment pipeline.
Test different screen sizes: With some many devices available to users, you should test for different screen sizes.
Espresso: While intended for View-based UIs, Espresso knowledge can still be helpful for some aspects of Compose testing.