compose-test-generator

Compose Test Generator

Generate idiomatic Compose UI tests following best practices.

Coding Standards

MANDATORY: This skill follows kotlin-compose-standards. All generated code MUST comply with these standards:

• Trailing comma EXCEPT for Modifier arguments
• Parameter order: required → Modifier → optional
• Modifier passed last when calling composables
• Each Modifier method on its own line
• New line at end of file

Quick Start

class MyComponentTest {
    @get:Rule
    val composeTestRule = createComposeRule()

    @Test
    fun component_displaysCorrectly() {
        composeTestRule.setContent {
            MyComponent(text = "Hello")
        }

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

Workflow

1. Read the composable to understand structure and state
2. Identify test scenarios: happy path, edge cases, interactions
3. Choose test type: behavior test, screenshot test, or both
4. Generate test file in appropriate location
5. Add test tags to composable if needed for reliable selection

References

Test Patterns

Stateless Component Test

@Test
fun button_showsLabel() {
    composeTestRule.setContent {
        PrimaryButton(label = "Submit", onClick = {})
    }
    composeTestRule.onNodeWithText("Submit").assertIsDisplayed()
}

Stateful Interaction Test

@Test
fun counter_incrementsOnClick() {
    composeTestRule.setContent {
        CounterScreen()
    }
    composeTestRule.onNodeWithText("0").assertIsDisplayed()
    composeTestRule.onNodeWithTag("increment_button").performClick()
    composeTestRule.onNodeWithText("1").assertIsDisplayed()
}

ViewModel Integration Test

@Test
fun screen_showsLoadedData() = runTest {
    val viewModel = MyViewModel(FakeRepository())

    composeTestRule.setContent {
        MyScreen(viewModel = viewModel)
    }

    composeTestRule.waitUntil {
        composeTestRule.onAllNodesWithTag("item")
            .fetchSemanticsNodes().isNotEmpty()
    }

    composeTestRule.onAllNodesWithTag("item").assertCountEquals(3)
}

Output Location

Place test files following project convention:

• Android: app/src/androidTest/java/.../ or app/src/test/java/.../
• KMP: shared/src/commonTest/kotlin/.../
• Screenshot tests: Usually in src/test/ (JVM-based)