Make JVM Android Integration Test Visible

Screenshot testing is key to validate your app's appearance and functionality. It efficiently detects visual issues and tests the app as users would use it, making it easier to spot problems. It's quicker than writing many assert statements, ensuring your app looks right and behaves correctly.

JVM tests, also known as local tests, are placed in the test/ directory and are run on a developer's PC or CI environment. On the other hand, device tests, also known as Instrumentation tests, are written in the androidTest/ directory and are run on real devices or emulators. Device testing can result in frequent failures due to the device environment, leading to false negatives. These failures are often hard to reproduce, making them tough to resolve.

Paparazzi is a great tool for visualizing displays within the JVM. However, it's incompatible with Robolectric, which also mocks the Android framework.

Roborazzi fills this gap. It integrates with Robolectric, allowing tests to run with Hilt and interact with components. Essentially, Roborazzi enhances Paparazzi's capabilities, providing a more efficient and reliable testing process by capturing screenshots with Robolectric.

Leveraging Roborazzi in Test Architecture: An Example

Integrating Roborazzi into the Architecture: An Example from DroidKaigi 2023 App

In the DroidKaigi 2023 app, Roborazzi was introduced from the early stages of development as part of the architectural design. This integration allowed the team to verify changes throughout the development process. The specific architectural decisions and how they were implemented can be found README.

Available on Maven Central.

This is an example of adding Robolectric to your project: https://github.com/takahirom/roborazzi-usage-examples/compare/b697...5c12

This library is dependent on Robolectric. Please see below to add Robolectric.

https://robolectric.org/getting-started/

This is an example of adding Roborazzi to your project: https://github.com/takahirom/roborazzi-usage-examples/commit/3a02

To take screenshots, please use Robolectric 4.10 alpha 1 or later and please add @GraphicsMode(GraphicsMode.Mode.NATIVE) to your test class.

@GraphicsMode(GraphicsMode.Mode.NATIVE)

Roborazzi is available on maven central.

This plugin simply creates Gradle tasks record, verify, compare and passes the configuration to the test.

build.gradle.kts

plugins {
  ...
  id("io.github.takahirom.roborazzi") version "[version]" apply false
}

plugins {
  ...
  id("io.github.takahirom.roborazzi")
}

buildscript {
  dependencies {
    ...
    classpath("io.github.takahirom.roborazzi:roborazzi-gradle-plugin:[version]")
  }
}

plugins {
    ...
    id("io.github.takahirom.roborazzi")
}

plugins {
  ...
  id "io.github.takahirom.roborazzi" version "[version]" apply false
}

plugins {
  ...
  id 'io.github.takahirom.roborazzi'
}

buildscript {
  dependencies {
    ...
    classpath "io.github.takahirom.roborazzi:roborazzi-gradle-plugin:[version]"
  }
}

apply plugin: "io.github.takahirom.roborazzi"

The comparison image, saved as [original]_compare.png, is shown below:

You can check the test report in build/reports/roborazzi/index.html

This uses JetNew from Compose Samples. You can check the pull request introducing Roborazzi to the compose-samples here.

You can take a screenshot by calling captureRoboImage().

app/src/test/java/../ManualTest.kt

import androidx.compose.ui.test.junit4.createAndroidComposeRule
import androidx.test.core.app.ActivityScenario
import androidx.test.espresso.Espresso.onView
import androidx.test.ext.junit.runners.AndroidJUnit4
import org.junit.Test
import org.junit.runner.RunWith
import org.robolectric.annotation.GraphicsMode

// All you need to do is use the captureRoboImage function in the test!
import com.github.takahirom.roborazzi.captureRoboImage


// Tips: You can use Robolectric while using AndroidJUnit4
@RunWith(AndroidJUnit4::class)
// Enable Robolectric Native Graphics (RNG) 
@GraphicsMode(GraphicsMode.Mode.NATIVE)
class ManualTest {
  @get:Rule
  val composeTestRule = createAndroidComposeRule<MainActivity>()

  @Test
  fun captureRoboImageSample() {
    // Tips: You can use Robolectric with Espresso API
    // launch
    ActivityScenario.launch(MainActivity::class.java)

    // Capture screen
    onView(ViewMatchers.isRoot())
      // If you don't specify a screenshot file name, Roborazzi will automatically use the method name as the file name for you.
      // The format of the file name will be as follows:
      // build/outputs/roborazzi/com_..._ManualTest_captureRoboImageSample.png
      .captureRoboImage()

    // Capture Jetpack Compose Node
    composeTestRule.onNodeWithTag("AddBoxButton")
      .onParent()
      .captureRoboImage("build/compose.png")
  }
}

Roborazzi supports the following APIs.

composeTestRule.onNodeWithTag("AddBoxButton")
  .captureRoboImage()

onView(ViewMatchers.isRoot())
  .captureRoboImage()

onView(withId(R.id.button_first))
  .captureRoboImage()

val view: View = composeTestRule.activity.findViewById<View>(R.id.button_second)
view.captureRoboImage()

captureRoboImage() {
  Text("Hello Compose!")
}

captureScreenRoboImage()

val bitmap: Bitmap = createBitmap(100, 100, Bitmap.Config.ARGB_8888)
  .apply {
    applyCanvas {
      drawColor(android.graphics.Color.YELLOW)
    }
  }
bitmap.captureRoboImage()

You can configure the device by using the @Config annotation and RobolectricDeviceQualifiers.

@RunWith(AndroidJUnit4::class)
@GraphicsMode(GraphicsMode.Mode.NATIVE)
@Config(qualifiers = RobolectricDeviceQualifiers.Pixel5)
class RoborazziTest {

@Test
@Config(qualifiers = RobolectricDeviceQualifiers.Pixel5)
fun test() {

@Config(qualifiers = "+night")

@Config(qualifiers = "+ja")

@Config(qualifiers = RobolectricDeviceQualifiers.MediumTablet)

It is easy to integrate Roborazzi to your GitHub Actions.

name: store screenshots

on:
  push

env:
  GRADLE_OPTS: "-Dorg.gradle.jvmargs=-Xmx6g -Dorg.gradle.daemon=false -Dkotlin.incremental=false"

jobs:
  test:
    runs-on: macos-latest

    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-java@v3.9.0
        with:
          distribution: 'zulu'
          java-version: 19

      - name: Gradle cache
        uses: gradle/gradle-build-action@v2

      - name: test
        run: |
          # Create screenshots
          ./gradlew app:recordRoborazziDebug --stacktrace

      # Upload screenshots to GitHub Actions Artifacts
      - uses: actions/upload-artifact@v3
        with:
          name: screenshots
          path: app/build/outputs/roborazzi
          retention-days: 30

name: verify test

on:
  push

env:
  GRADLE_OPTS: "-Dorg.gradle.jvmargs=-Xmx6g -Dorg.gradle.daemon=false -Dkotlin.incremental=false"

jobs:
  test:
    runs-on: macos-latest

    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-java@v3.9.0
        with:
          distribution: 'zulu'
          java-version: 19

      - name: Gradle cache
        uses: gradle/gradle-build-action@v2

      # Download screenshots from main branch
      - uses: dawidd6/action-download-artifact@v2
        with:
          name: screenshots
          path: app/build/outputs/roborazzi
          workflow: test.yaml
          branch: main

      - name: verify test
        id: verify-test
        run: |
          # If there is a difference between the screenshots, the test will fail.
          ./gradlew app:verifyRoborazziDebug --stacktrace

      - uses: actions/upload-artifact@v3
        if: ${{ always() }}
        with:
          name: screenshot-diff
          path: app/build/outputs/roborazzi
          retention-days: 30

      - uses: actions/upload-artifact@v3
        if: ${{ always() }}
        with:
          name: screenshot-diff-reports
          path: app/build/reports
          retention-days: 30

      - uses: actions/upload-artifact@v3
        if: ${{ always() }}
        with:
          name: screenshot-diff-test-results
          path: app/build/test-results
          retention-days: 30

For those who are looking for a more advanced example, we have prepared a sample repository that demonstrates how to use Roborazzi to compare snapshot results on GitHub pull requests. This sample showcases the integration of Roborazzi with GitHub Actions workflows, making it easy to visualize and review the differences between snapshots directly in the pull request comments.

Check out the roborazzi-compare-on-github-comment-sample repository to see this powerful feature in action and learn how to implement it in your own projects.

Example of the comment

RoborazziRule is a JUnit rule for Roborazzi. RoborazziRule is optional. You can use captureRoboImage() without this rule.

RoborazziRule has two features.

1. Provide context such as RoborazziOptions and outputDirectoryPath etc for captureRoboImage().
2. Capture screenshots for each test when specifying RoborazziRule.options.captureType.

For example, The following code generates an output file named **custom_outputDirectoryPath**/**custom_outputFileProvider**-com.github.takahirom.roborazzi.sample.RuleTestWithPath.captureRoboImage.png :

@RunWith(AndroidJUnit4::class)
@GraphicsMode(GraphicsMode.Mode.NATIVE)
class RuleTestWithPath {
  @get:Rule
  val roborazziRule = RoborazziRule(
    options = Options(
      outputDirectoryPath = "$DEFAULT_ROBORAZZI_OUTPUT_DIR_PATH/custom_outputDirectoryPath",
      outputFileProvider = { description, outputDirectory, fileExtension ->
        File(
          outputDirectory,
          "custom_outputFileProvider-${description.testClass.name}.${description.methodName}.$fileExtension"
        )
      }
    ),
  )

  @Test
  fun captureRoboImage() {
    launch(MainActivity::class.java)
    // The file will be saved using the rule's outputDirectoryPath and outputFileProvider
    onView(isRoot()).captureRoboImage()
  }
}

@Test
fun captureRoboGifSample() {
  onView(ViewMatchers.isRoot())
    .captureRoboGif("build/test.gif") {
      // launch
      ActivityScenario.launch(MainActivity::class.java)
      // move to next page
      onView(withId(R.id.button_first))
        .perform(click())
      // back
      pressBack()
      // move to next page
      onView(withId(R.id.button_first))
        .perform(click())
    }
}

Note
You don't need to use RoborazziRule if you're using captureRoboImage().

With the JUnit test rule, you do not need to name the gif image, and if you prefer, you can output the gif image only if the test fails.

This test will output this file.

build/outputs/roborazzi/com.github.takahirom.roborazzi.sample.RuleTestWithOnlyFail_captureRoboGifSampleFail.gif

@RunWith(AndroidJUnit4::class)
@GraphicsMode(GraphicsMode.Mode.NATIVE)
class RuleTestWithOnlyFail {
  @get:Rule
  val roborazziRule = RoborazziRule(
    captureRoot = onView(isRoot()),
    options = Options(
      onlyFail = true,
      captureType = RoborazziRule.CaptureType.Gif,
    )
  )

  @Test
  fun captureRoboLastImageSampleFail() {
    // launch
    ActivityScenario.launch(MainActivity::class.java)
    // move to next page
    onView(withId(R.id.button_first))
      .perform(click())
    // should fail because the button does not exist
    // Due to failure, the gif image will be saved in the outputs folder.
    onView(withId(R.id.button_first))
      .perform(click())
  }
}

Test target

@Composable
fun SampleComposableFunction() {
  var count by remember { mutableStateOf(0) }
  Column(
    Modifier
      .size(300.dp)
  ) {
    Box(
      Modifier
        .testTag("AddBoxButton")
        .size(50.dp)
        .clickable {
          count++
        }
    )
    (0..count).forEach {
      Box(
        Modifier
          .size(30.dp)
      )
    }
  }
}

Test (Just add RoborazziRule)

@RunWith(AndroidJUnit4::class)
@GraphicsMode(GraphicsMode.Mode.NATIVE)
class ComposeTest {
  @get:Rule
  val composeTestRule = createAndroidComposeRule<ComponentActivity>()

  @get:Rule
  val roborazziRule = RoborazziRule(
    composeRule = composeTestRule,
    captureRoot = composeTestRule.onRoot(),
    options = RoborazziRule.Options(
      RoborazziRule.CaptureType.Gif()
    )
  )

  @Test
  fun composable() {
    composeTestRule.setContent {
      SampleComposableFunction()
    }
    (0 until 3).forEach { _ ->
      composeTestRule
        .onNodeWithTag("AddBoxButton")
        .performClick()
    }
  }
}

You can use some RoborazziRule options

/**
 * This rule is a JUnit rule for roborazzi.
 * This rule is optional. You can use [captureRoboImage] without this rule.
 *
 * This rule have two features.
 * 1. Provide context such as `RoborazziOptions` and `outputDirectoryPath` etc for [captureRoboImage].
 * 2. Capture screenshots for each test when specifying RoborazziRule.options.captureType.
 */
class RoborazziRule private constructor(
  private val captureRoot: CaptureRoot,
  private val options: Options = Options()
) : TestWatcher() {
  /**
   * If you add this annotation to the test, the test will be ignored by
   * roborazzi's CaptureType.LastImage, CaptureType.AllImage and CaptureType.Gif.
   */
  annotation class Ignore

  data class Options(
    val captureType: CaptureType = CaptureType.None,
    /**
     * output directory path
     */
    val outputDirectoryPath: String = provideRoborazziContext().outputDirectory,

    val outputFileProvider: FileProvider = provideRoborazziContext().fileProvider
      ?: defaultFileProvider,
    val roborazziOptions: RoborazziOptions = provideRoborazziContext().options,
  )

  sealed interface CaptureType {
    /**
     * Do not generate images. Just provide the image path to [captureRoboImage].
     */
    object None : CaptureType

    /**
     * Generate last images for each test
     */
    data class LastImage(
      /**
       * capture only when the test fail
       */
      val onlyFail: Boolean = false,
    ) : CaptureType

    /**
     * Generate images for Each layout change like TestClass_method_0.png for each test
     */
    data class AllImage(
      /**
       * capture only when the test fail
       */
      val onlyFail: Boolean = false,
    ) : CaptureType

    /**
     * Generate gif images for each test
     */
    data class Gif(
      /**
       * capture only when the test fail
       */
      val onlyFail: Boolean = false,
    ) : CaptureType
  }

When comparing images, you may encounter differences due to minor changes related to antialiasing. You can use the options below to avoid this.

@get:Rule
val roborazziRule = RoborazziRule(
    options = RoborazziRule.Options(
        roborazziOptions = RoborazziOptions(
            compareOptions = RoborazziOptions.CompareOptions(
                changeThreshold = 0.01, // For 1% accepted difference
                imageComparator = SimpleImageComparator(
                    maxDistance = 0.007F, // 0.001F is default value from Differ
                    vShift = 2, // Increasing the shift can help resolve antialiasing issues
                    hShift = 2 // Increasing the shift can help resolve antialiasing issues
                )
            )
        )
    )
)

You can set roborazzi.record.image.extension to webp in your gradle.properties file to generate WebP images.

roborazzi.record.image.extension=webp

WebP is a lossy image format by default, which can make managing image differences challenging. To address this, we provide a lossless WebP image comparison feature. To enable WebP support, add testImplementation("io.github.darkxanter:webp-imageio:0.3.3") to your build.gradle.kts file.

onView(ViewMatchers.withId(R.id.textview_first))
  .captureRoboImage(
    roborazziOptions = RoborazziOptions(
      recordOptions = RoborazziOptions.RecordOptions(
        imageIoFormat = LosslessWebPImageIoFormat(),
      ),
    )
  )

You can also use other image formats by implementing your own AwtImageWriter and AwtImageLoader.

data class JvmImageIoFormat(
  val awtImageWriter: AwtImageWriter,
  val awtImageLoader: AwtImageLoader
) : ImageIoFormat

If you are having trouble debugging your test, try Dump mode as follows.

Please check out RoborazziOptions for available Roborazzi options.

Roborazzi provides support for generating screenshot tests and easy setup for Jetpack Compose Preview. This support uses ComposablePreviewScanner to scan the Composable Previews in your project.

You first need to add the Roborazzi plugin to your project. Please refer to the setup guide for more information. Then you can enable the Compose Preview screenshot test generation feature by adding the following configuration to your build.gradle.kts file:

roborazzi {
  generateComposePreviewRobolectricTests {
    enable = true
  }
}

The plugin will not automatically change your settings or add dependencies to prevent conflicts with your existing setup. However, it will provide instructions on what to do next, such as adding dependencies and required code. You can also check the sample project for a complete example.

After that, you can run the recordRoborazziDebug task to generate screenshots using the generated tests, as described in the setup guide.

You can customize the generated test by adding the following configuration to your build.gradle.kts file:

roborazzi {
  @OptIn(ExperimentalRoborazziApi::class)
  generateComposePreviewRobolectricTests {
    enable = true
    // The package names to scan for Composable Previews.
    packages = listOf("com.example")
    // robolectricConfig will be passed to Robolectric's @Config annotation in the generated test class.
    // See https://robolectric.org/configuring/ for more information.
    robolectricConfig = mapOf(
      "sdk" to "[32]",
      "qualifiers" to "RobolectricDeviceQualifiers.Pixel5",
    )
    // If true, the private previews will be included in the test.
    includePrivatePreviews = true
    // The fully qualified class name of the custom test class that implements [com.github.takahirom.roborazzi.ComposePreviewTester].
    testerQualifiedClassName = "com.example.MyCustomComposePreviewTester"
  }
}

Note
If you are using build.gradle instead of build.gradle.kts, you need to use the set method for each assignment, like

generateComposePreviewRobolectricTests.packages.set(["com.example"])

Roborazzi provides a helper function for ComposablePreviewScanner. You can add the following dependency to your project to use the helper function:

testImplementation("io.github.takahirom.roborazzi:roborazzi-compose-preview-scanner-support:[version]")

Then you can use the ComposablePreview<AndroidPreviewInfo>.captureRoboImage() function to capture the Composable Preview using the settings in Preview annotations. To obtain the ComposablePreview object, please refer to ComposablePreviewScanner.

fun ComposablePreview<AndroidPreviewInfo>.captureRoboImage(
  filePath: String,
  roborazziOptions: RoborazziOptions
)

Currently, we don't support all the annotation options provided by the Compose Preview. You can check the supported annotations in the source code. We are looking forward to your contributions to support more annotation options.

Roborazzi supports AI-powered image assertion. AI-powered image assertion is an experimental feature. Screenshot tests are a great way to verify your app's UI, but verifying the content of the images can be a tedious and time-consuming task. This manual effort reduces scalability. Roborazzi can help automate this process through AI-powered image assertion, making it more efficient and scalable.

There are two new library modules: io.github.takahirom.roborazzi:roborazzi-ai-gemini and io.github.takahirom.roborazzi:roborazzi-ai-openai for AI-powered image assertion.

roborazzi-ai-gemini leverages Gemini and generative-ai-kmp, while roborazzi-ai-openai utilizes the OpenAI API through raw HTTP API calls implemented with Ktor and KotlinX Serialization

...
@get:Rule
val composeTestRule = createAndroidComposeRule<MainActivity>()

@get:Rule
val roborazziRule = RoborazziRule(
  options = RoborazziRule.Options(
    roborazziOptions = RoborazziOptions(
      compareOptions = RoborazziOptions.CompareOptions(
        aiAssertionOptions = AiAssertionOptions(
          aiAssertionModel = GeminiAiAssertionModel(
            // DO NOT HARDCODE your API key in your code.
            // This is an example passing API Key through unitTests.all{ environment(key, value) }
            apiKey = System.getenv("gemini_api_key") ?: ""
          ),
        )
      )
    )
  )
)

@Test
fun captureWithAi() {
  ROBORAZZI_DEBUG = true
  onView(ViewMatchers.isRoot())
    .captureRoboImage(
      roborazziOptions = provideRoborazziContext().options.addedAiAssertions(
        AiAssertionOptions.AiAssertion(
          assertionPrompt = "it should have PREVIOUS button",
          requiredFulfillmentPercent = 90,
        ),
        AiAssertionOptions.AiAssertion(
          assertionPrompt = "it should show First Fragment",
          requiredFulfillmentPercent = 90,
        )
      )
    )
}

AI-Powered Image Assertion runs only when the images are different. If the images are the same, AI-Powered Image Assertion is skipped.
This is because AI-Powered Image Assertion can be slow and expensive.

You can use manual image assertion with Roborazzi. This allows you to utilize local LLMs or other LLMs. Manual Image Assertion doesn't require adding any dependencies other than Roborazzi itself.

You must provide the AiAssertionModel to RoborazziOptions to use manual image assertion.

interface AiAssertionModel {
  fun assert(
    referenceImageFilePath: String,
    comparisonImageFilePath: String,
    actualImageFilePath: String,
    aiAssertionOptions: AiAssertionOptions
  ): AiAssertionResults
}

compareOptions = RoborazziOptions.CompareOptions(
  aiAssertionOptions = AiAssertionOptions(
    aiAssertionModel = object : AiAssertionOptions.AiAssertionModel {
      override fun assert(
        comparisonImageFilePath: String,
        aiAssertionOptions: AiAssertionOptions
      ): AiAssertionResults {
        // You can use any LLMs here to create AiAssertionResults
        return AiAssertionResults(
          aiAssertionResults = aiAssertionOptions.aiAssertions.map { assertion ->
            AiAssertionResult(
              assertionPrompt = assertion.assertionPrompt,
              fulfillmentPercent = fulfillmentPercent,
              requiredFulfillmentPercent = assertion.requiredFulfillmentPercent,
              failIfNotFulfilled = assertion.failIfNotFulfilled,
              explanation = "This is a manual test.",
            )
          }
        )
      }
    },
    aiAssertions = listOf(
      AiAssertionOptions.AiAssertion(
        assertionPrompt = "it should have PREVIOUS button",
        requiredFulfillmentPercent = 90,
      ),
    ),
  )
)
          ...

https://plugins.jetbrains.com/plugin/24561-roborazzi

Demo of Roborazzi IntelliJ IDEA and Android Studio Plugin.

The Roborazzi plugin enhances your development workflow by automatically displaying screenshots related to Roborazzi's screenshot tests within IntelliJ IDEA. Easily view and verify visual outputs directly in your IDE, streamlining your testing and development process.

Roborazzi supports Compose Multiplatform iOS. You can use Roborazzi with Compose iOS as follows:

Gradle settings

plugins {
  kotlin("multiplatform")
  id("org.jetbrains.compose")
  id("io.github.takahirom.roborazzi")
}

kotlin {
  sourceSets {
    ...
    val appleTest by getting {
      dependencies {
        implementation(project("io.github.takahirom.roborazzi:roborazzi-compose-ios:[1.13.0 or higher]"))
        implementation(kotlin("test"))
      }
    }
  ...

Test with Roborazzi

class IosTest {
  @OptIn(ExperimentalTestApi::class)
  @Test
  fun test() {
    runComposeUiTest {
      setContent {
        MaterialTheme {
          Column {
            Button(
              modifier = Modifier.alpha(alpha),
              onClick = { }) {
              Text("Hello World")
            }
            Box(
              modifier = Modifier
                .background(Color.Red.copy(alpha = alpha), MaterialTheme.shapes.small)
                .size(100.dp),
            )
          }
        }
      }
      onRoot().captureRoboImage(this, filePath = "ios.png")
      onNodeWithText("Hello World").captureRoboImage(
        this,
        filePath = "ios_button.png"
      )
    }
  }
}

Then, you can run the Gradle tasks for iOS Support, just like you do for Android Support.

./gradlew recordRoborazzi[SourceSet]

./gradlew recordRoborazziIosSimulatorArm64
./gradlew compareRoborazziIosSimulatorArm64
./gradlew verifyRoborazziIosSimulatorArm64
...

The currently implemented features for iOS support are as follows:

We are migrating JVM implementation to Multiplatform implementation. So, some features are not supported yet. We are looking for contributors to help us implement these features.

Roborazzi supports Compose Desktop. You can use Roborazzi with Compose Desktop as follows:

Gradle settings

plugins {
  kotlin("multiplatform")
  id("org.jetbrains.compose")
  id("io.github.takahirom.roborazzi")
}

kotlin {
  // You can use your source set name
  jvm("desktop")
  sourceSets {
    ...
    val desktopTest by getting {
      dependencies {
        implementation(project("io.github.takahirom.roborazzi:roborazzi-compose-desktop:[1.6.0-alpha-2 or higher]"))
        implementation(kotlin("test"))
      }
    }
    ...

Test target Composable function

@Composable
fun App() {
  var text by remember { mutableStateOf("Hello, World!") }

  MaterialTheme {
    Button(
      modifier = Modifier.testTag("button"),
      onClick = {
        text = "Hello, Desktop!"
      }) {
      Text(
        style = MaterialTheme.typography.h2,
        text = text
      )
    }
  }
}

Test with Roborazzi

class MainKmpTest {
  @OptIn(ExperimentalTestApi::class)
  @Test
  fun test() = runDesktopComposeUiTest {
    setContent {
      App()
    }
    val roborazziOptions = RoborazziOptions(
      recordOptions = RoborazziOptions.RecordOptions(
        resizeScale = 0.5
      ),
      compareOptions = RoborazziOptions.CompareOptions(
        changeThreshold = 0F
      )
    )
    onRoot().captureRoboImage(roborazziOptions = roborazziOptions)

    onNodeWithTag("button").performClick()

    onRoot().captureRoboImage(roborazziOptions = roborazziOptions)
  }
}

Then, you can run the Gradle tasks for Desktop Support, just like you do for Android Support.

./gradlew recordRoborazzi[SourceSet]

./gradlew recordRoborazziDesktop
./gradlew compareRoborazziDesktop
./gradlew verifyRoborazziDesktop
...

If you use the Kotlin JVM plugin, the task will be recordRoborazzi**Jvm**.

The sample image

You can configure the following options in your gradle.properties file. You can also use -P to set the options in the command line. For example, ./gradlew test -Proborazzi.test.record=true.

This option enables you to configure the behavior of Roborazzi. By default, all settings are set to false. For additional configuration options, please refer to the 'Apply Roborazzi Gradle Plugin' section.

roborazzi.test.record=true
# roborazzi.test.compare=true
# roborazzi.test.verify=true

This option lets you set the resize scale for the image being recorded. The default value is 1.0.

roborazzi.record.resizeScale=0.5

This setting allows you to specify the file path strategy for the recorded image. The default strategy is relativePathFromCurrentDirectory. If you choose relativePathFromRoborazziContextOutputDirectory, the file will be saved in the output directory specified by RoborazziRule.Options.outputDirectoryPath.

roborazzi.record.filePathStrategy=relativePathFromRoborazziContextOutputDirectory

This option enables you to define the naming strategy for the recorded image. The default strategy is testPackageAndClassAndMethod.

• If you choose testPackageAndClassAndMethod, the file name will be com.example.MyTest.testMethod.png.
• If you choose escapedTestPackageAndClassAndMethod, the file name will be com_example_MyTest.testMethod.png.
• If you choose testClassAndMethod, the file name will be MyTest.testMethod.png.

roborazzi.record.namingStrategy=testClassAndMethod

This option allows you to clean up old screenshots. By default, this option is set to false. The reason why Roborazzi does not delete old screenshots by default is that Roborazzi doesn't know if you are running filtered tests or not. If you are running filtered tests, Roborazzi will delete the screenshots that are not related to the current test run.

roborazzi.cleanupOldScreenshots=true

I recommend setting it.systemProperties["robolectric.pixelCopyRenderMode"] = "hardware" in your build.gradle file to enhance the accuracy of your screenshots. For more details, please refer to the issue.

android {
    testOptions {
    ...
        unitTests {
            isIncludeAndroidResources = true
            isReturnDefaultValues = true
            all {
                it.systemProperties["robolectric.pixelCopyRenderMode"] = "hardware"
            }

A: To run only screenshot tests, you can configure your project with the following:

android {
    testOptions {
        unitTests {
            all {
                // -Pscreenshot to filter screenshot tests
                it.useJUnit {
                    if (project.hasProperty("screenshot")) {
                        includeCategories("io.github.takahirom.roborazzi.testing.category.ScreenshotTests")
                    }
                }
            }
        }
    }
}

Include the -Pscreenshot property, and only the screenshot tests will be run.

Note: This feature is not provided in the Roborazzi library itself, to keep it simple and utilize JUnit's built-in features for test filtering.

You can also annotate your tests like this:

/**
 * You can filter ScreenshotTests using -Pscreenshot parameter
 */
interface ScreenshotTests

@Test
@Category(ScreenshotTests::class)
fun checkLaunchShot() {
  onRoot().captureRoboImage(roborazziOptions = roborazziOptions)
}

This allows you to create a category of screenshot tests and filter them using the -Pscreenshot property, thus making it easier to run only those specific tests.

A: To execute screenshot tests using Android Studio's Run button, configure your project as follows:

gradle.properties

roborazzi.test.record=true

After that, you can execute screenshot tests using either Android Studio's Run or Debug button as you normally would.

A: If your screenshot tests are not capturing images, there may be several patterns that are causing this issue. Please follow these troubleshooting steps:

• Enable Debugging: Set ROBORAZZI_DEBUG = true to see logs.
• Check Plugin: Ensure that the plugin is properly applied.
• Run Task: Verify that the recordRoborazziDebug task is running.
• Call Method: Confirm that captureRoboImage() is being called.

By following these steps, you should be able to identify and resolve the issue causing the screenshot tests to not capture images.

A: This warning may occur with Gradle 7.5. Upgrade to Gradle 7.6.2 to resolve this issue. Change the distribution URL in gradle-wrapper.properties:

distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.2-bin.zip

A: As of now, there is no direct support for running Roborazzi with Bazel. However, it is possible to do so. Please refer to the following comment for more details: Roborazzi Bazel Support Comment

A: The behavior you are experiencing may be related to caching issues. Although it's experimental, you can set the outputDir parameter in your build.gradle file to handle caching and improve the stability of your tests. This parameter allows you to specify the output directory for your screenshots, which can help in managing the cache. Here is how you can set it up: If you use the default output directory(module/build/outputs/roborazzi), specifying the outputDir parameter is not necessary. For more reference, you can check out the issue.

roborazzi {
    outputDir = "src/your/screenshot/folder"
}

A: This is a known issue caused by variations in how graphics libraries render components on different platforms. This issue is due to variations in how graphics libraries render components on different platforms. As we've seen with Now in Android, there are no guarantees for identical rendering across all environments. To ensure more consistent results, consider configuring your continuous integration (CI) environment to both record and test screenshots. This setup minimizes discrepancies by using the same settings and resources for all tests.

A: First, please check if you are using the correct version of the Android SDK. Consider using API level 28 or higher because it seems that Robolectric Native Graphics doesn't work property on older SDK versions.

You can specify the SDK version like @Config(sdk = [33]) or by using robolectric.properties with sdk=33.
https://robolectric.org/configuring/

If your images are mostly fine but there are some drawing issues like shadows or shape graphics, you can try using Robolectric's Hardware Rendering mode. Please refer to this issue.

A: You may solve this by using unitTests.maxHeapSize to adjust the unit test heap size as follows:

android {
  ...
  testOptions {
    unitTests.all {
      maxHeapSize = "4096m"
    }
  }
}

It is discussed in this issue. Additionally, it might be worth trying to run your tests with VisualVM to monitor memory usage and identify potential leaks.

A: It is discussed in this issue.
To enable the display of Roborazzi tasks, please enable Configure all Gradle tasks during Gradle Sync (this can make Gradle Sync slower) in the Settings | Experimental | Gradle.