Kakao Compose Test Rule

How to reduce boilerplate

When we writing UI test for compose we need to inject composeTestRule in to each onComposeScreen call.

    @Test
    fun simpleTest() {
        onComposeScreen<MainActivityScreen>(composeTestRule) {
            myButton {
                assertIsDisplayed()
                assertTextContains("Button 1")
            }
        }
    }

That's creating a lot of boilerplate in the code. But you can avoid it with KakaoComposeTestRule Example

class SimpleTestGlobalSemantic {

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

    @get:Rule
    val kakaoComposeTestRule = KakaoComposeTestRule(
        semanticsProvider = composeTestRule
    )

    @Test
    fun simpleTest() {
        onComposeScreen<GlobalSemanticScreen> {
            myText1 {
                assertIsDisplayed()
                assertTextContains("Simple text 1")
            }
        }
    }
}

This rule will create a wrapper around composeTestRule and provide it into ComposeScreen or KNode implicitly, what will reduce boilerplate in the tests.

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Global override useUnmergedTree

Compose framework always will try to optimise view tree and squash views if it acceptable. For example two Text view will be squashed into one, what can create misleading in tests. By default in Espresso useUnmergedTree set as false, but on practice for UI test we want to have it as true in many cases. With KakaoComposeTestRule we can override it globally.

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

    @get:Rule
    val kakaoComposeTestRule = KakaoComposeTestRule(
        semanticsProvider = composeTestRule,
        useUnmergedTree = true
    )