Screenshot Tests

Screenshot Tests (Paparazzi)

We use Paparazzi for screenshot testing via the screenshot-testing module.

Recording Screenshots

Record (update) screenshots after UI changes:

./gradlew :<module>:recordPaparazziDebug

To record a specific test class only:

./gradlew :<module>:recordPaparazziDebug --tests "com.stripe.android.package.MyScreenshotTest"

Wildcard form also works:

./gradlew :<module>:recordPaparazziDebug --tests "*.MyScreenshotTest"

New or updated screenshots are written to <module>/src/test/snapshots/images/ and added to the Git staging area.

Verifying Screenshots

Verify screenshots match recorded baselines (used on CI):

./gradlew :<module>:verifyPaparazziDebug

Failure diffs are written to <module>/out/failures (git-ignored).

Test Class Structure

internal class MyScreenshotTest {

    @get:Rule
    val paparazziRule = PaparazziRule(
        SystemAppearance.entries,        // Light/Dark
        PaymentSheetAppearance.entries,  // Default/Custom/Crazy appearances
        FontSize.entries,                // Default/Large font
        boxModifier = Modifier.padding(horizontal = 16.dp),
    )

    @Test
    fun testDefault() {
        paparazziRule.snapshot {
            MyComposable(/* ... */)
        }
    }
}

• PaparazziRule generates all permutations of the config options automatically.
• Each test produces one snapshot per permutation (e.g., 12 images for 2 themes x 3 appearances x 2 font sizes).
• Snapshots are named <package>_<class>_<method>[<permutation>].png.

Available Config Options

Common Mistakes

• Using -Precord or other flags — Paparazzi uses a separate recordPaparazziDebug task, not a project property.
• Running testDebugUnitTest to record — this only verifies against existing snapshots; use recordPaparazziDebug to update them.
• Forgetting to commit updated snapshots — recorded images go into src/test/snapshots/images/ and must be committed.

Source: stripe/stripe-android — distributed by TomeVault.