Configuring Test Dependencies

Configuring Test Dependencies — Get the Gradle Matrix Right

Compose UI tests fail at the dependency layer in three predictable ways: the JUnit4 surface is on the wrong source set, the ui-test-manifest artifact is missing or on the wrong configuration, or the host-test trio is incomplete. This skill encodes the exact matrix and the lint warning that polices it. Subsequent skills (choosing-test-rule-vs-runtest/SKILL.md, setting-up-host-vs-device-tests/SKILL.md) assume the dependencies are correct.

When to use this skill

• The user reports java.lang.RuntimeException: Could not launch activity within 45 seconds. Examined activities: ... androidx.activity.ComponentActivity or ActivityNotFoundException.
• The IDE flags createComposeRule as unresolved or import androidx.compose.ui.test.junit4.createComposeRule as red.
• Lint surfaces TestManifestGradleConfiguration (severity WARNING) on a build.gradle.kts line.
• The user wants to add Robolectric / host (JVM) tests for Compose and asks which artifacts to depend on.
• The user wants to opt into enableAccessibilityChecks(...) and is unsure which artifact owns it.

When NOT to use this skill

• Dependencies are already correct and the user is choosing between createComposeRule() and runComposeUiTest { } — use ./choosing-test-rule-vs-runtest/SKILL.md.
• Dependencies compile but the test runs in the wrong source set (test/ vs androidTest/) — use ./setting-up-host-vs-device-tests/SKILL.md.
• The test compiles and runs but is flaky/timing-out — start with ../../synchronization/synchronizing-with-idle/SKILL.md.

Prerequisites

• Android Gradle Plugin with the com.android.application or com.android.library plugin applied.
• A Compose-enabled module (the org.jetbrains.kotlin.plugin.compose plugin or buildFeatures.compose = true).
• A JUnit4 dependency on the test classpath (Compose's ui-test-junit4 artifact still uses JUnit4; JUnit5 requires a third-party Vintage engine bridge and is out of scope).

Workflow

• 1. Decide which test surfaces the module needs. A typical Compose feature module wants three: instrumentation tests for screenshot/RenderThread/full-stack coverage, host (Robolectric) tests for fast logic checks, and the manifest helper for createComposeRule(). Pick from the matrix in step 2.

• 2. Add dependencies on the correct configurations. Copy this into the module's build.gradle.kts:

dependencies {
    // --- Instrumentation tests (src/androidTest/) ---
    androidTestImplementation("androidx.compose.ui:ui-test-junit4")
    // MUST be debugImplementation (see Pattern: WRONG vs RIGHT for ui-test-manifest below)
    debugImplementation("androidx.compose.ui:ui-test-manifest")

    // --- Host tests with Robolectric (src/test/) ---
    testImplementation("androidx.compose.ui:ui-test")            // common test API
    testImplementation("androidx.compose.ui:ui-test-junit4")     // ComposeTestRule + createComposeRule
    testImplementation("androidx.compose.ui:ui-test-manifest")   // ComponentActivity manifest entry
    testImplementation("org.robolectric:robolectric:4.13")       // pin a version

    // --- Optional: accessibility validation (API 34+) ---
    androidTestImplementation("androidx.compose.ui:ui-test-junit4-accessibility")
    // Or, when using runComposeUiTest { } (no Rule):
    androidTestImplementation("androidx.compose.ui:ui-test-accessibility")
}

The exact GA versions come from the Compose UI BOM or the developer's chosen composeVersion. Pin Robolectric independently — it does not ship in the Compose BOM.

• 3. If the test fails with ActivityNotFoundException for androidx.activity.ComponentActivity, the manifest artifact is the cause 99 percent of the time. That artifact is a single-file library that merges this <activity> entry into the test APK manifest, taken from compose/ui/ui-test-manifest/src/main/AndroidManifest.xml:

<activity android:theme="@android:style/Theme.Material.Light.NoActionBar"
    android:name="androidx.activity.ComponentActivity" android:exported="true" />

Without that entry, createComposeRule() and runComposeUiTest { } (which both default to launching androidx.activity.ComponentActivity via ActivityScenario.launch) crash at launch time. Diagnosis:

• Confirm ui-test-manifest is in the dependency list at all.

• Confirm it is on debugImplementation (or testImplementation for host tests). If it is on androidTestImplementation, lint flags it and Gradle still wires it in — but the AGP variant model intentionally separates debug and androidTest manifest merging, and putting it on androidTestImplementation does NOT merge the <activity> into the host APK that the instrumentation runs against. The lint check exists precisely to catch this.

• 4. Address the TestManifestGradleConfiguration lint warning by moving the dependency to debugImplementation. The lint check lives in compose/ui/ui-test-manifest-lint/src/main/java/androidx/compose/ui/test/manifest/lint/GradleDebugConfigurationDetector.kt. Severity is Severity.WARNING and the quick fix replaces the configuration name with debugImplementation. The check fires when the artifact appears on implementation, api, compileOnly, runtimeOnly, androidTestImplementation, testImplementation, or any custom configuration whose name starts with android / test / one of the supported config names.

• 5. Decide whether the manifest artifact is needed at all. It is required when:

  • The test uses createComposeRule() (no type parameter — defaults to androidx.activity.ComponentActivity).
  • The test uses runComposeUiTest { } (no type parameter — same default).

  It is NOT required when:

  • The test uses createAndroidComposeRule<MyActivity>() AND the developer declares <activity android:name=".MyActivity" .../> themselves in src/androidTest/AndroidManifest.xml (or src/debug/AndroidManifest.xml).
  • The test uses createEmptyComposeRule() and launches its own ActivityScenario against an Activity already declared in the production manifest.

• 6. For host tests, ensure all three artifacts are on testImplementation. Robolectric drives the JVM Looper, but Compose's idling/clock implementations require ui-test (common) plus ui-test-junit4 (ComposeTestRule interface and createComposeRule actual). Without ui-test-manifest on testImplementation, Robolectric throws the same ActivityNotFoundException because it parses the same manifest. The host source set in androidx itself uses this configuration — see compose/ui/ui-test/src/androidHostTest/kotlin/androidx/compose/ui/test/RobolectricComposeTest.kt.

• 7. Add accessibility artifacts only if the developer plans to call enableAccessibilityChecks. They are independent of the JUnit4 surface:

  • ui-test-accessibility extends ComposeUiTest (the receiver of runComposeUiTest { }).
  • ui-test-junit4-accessibility extends ComposeTestRule / AndroidComposeTestRule. Both are @RequiresApi(34), both are no-op on Robolectric (Build.FINGERPRINT == "robolectric" triggers a logged warning) — see the accessibility skill in this repo for follow-up.

• 8. Sync Gradle and re-run the test. A clean ./gradlew :app:connectedDebugAndroidTest (instrumentation) or ./gradlew :app:testDebugUnitTest (host) should compile and locate ComponentActivity.