Test a Composable

In order to test a @Composable function, you must first declare an instance variable of the ComposableScreenshotRule class. You will be using this rule instead of the default ScreenshotTestRule.

ComposableScreenshotRule provides a setCompose() method which accepts a composable function in which you can specify your own custom compositions. You can invoke the setCompose() method on the rule instance and declare any Compose UI functions you wish to test.

The contents of setCompose() are rendered as the contents of the provided ComposableTestActivity. ComposableTestActivity is a simple activity with single root ComposeView with a Color.White background.

The ComposeView provided by ComposableTestActivity is defined with WRAP_CONTENT layout parameters and so the captured image will be constrained to fit only the bounds of the @Composable.

If necessary, you can access the root view with the identifier dev.testify.compose.R.id.compose_container.

Example

class ComposableScreenshotTest {

    @get:Rule val rule = ComposableScreenshotRule()

    @ScreenshotInstrumentation
    @Test
    fun default() {
        rule
            .setCompose {
                Text(text = "Hello, Testify!")
            }
            .assertSame()
    }
}