Merge pull request #5214 from element-hq/feature/bma/a11yScreenshotTest

Introduce a11y screenshot test

Author: bmarty

features/home/impl/src/main/kotlin/io/element/android/features/home/impl/HomeView.kt

@@ -31,6 +31,7 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.tooling.preview.PreviewParameter
 import androidx.compose.ui.unit.dp
 import dev.chrisbanes.haze.hazeEffect
@@ -313,3 +314,22 @@ internal fun HomeViewPreview(@PreviewParameter(HomeStateProvider::class) state:
         leaveRoomView = {}
     )
 }
+
+@Preview
+@Composable
+internal fun HomeViewA11yPreview() = ElementPreview {
+    HomeView(
+        homeState = aHomeState(),
+        onRoomClick = {},
+        onSettingsClick = {},
+        onSetUpRecoveryClick = {},
+        onConfirmRecoveryKeyClick = {},
+        onStartChatClick = {},
+        onRoomSettingsClick = {},
+        onReportRoomClick = {},
+        onMenuActionClick = {},
+        onDeclineInviteAndBlockUser = {},
+        acceptDeclineInviteView = {},
+        leaveRoomView = {}
+    )
+}

tests/konsist/src/test/kotlin/io/element/android/tests/konsist/KonsistPreviewTest.kt

@@ -12,6 +12,7 @@ import com.google.common.truth.Truth.assertThat
 import com.lemonappdev.konsist.api.Konsist
 import com.lemonappdev.konsist.api.ext.list.withAllAnnotationsOf
 import com.lemonappdev.konsist.api.ext.list.withName
+import com.lemonappdev.konsist.api.ext.list.withNameEndingWith
 import com.lemonappdev.konsist.api.ext.list.withoutName
 import com.lemonappdev.konsist.api.verify.assertEmpty
 import com.lemonappdev.konsist.api.verify.assertTrue
@@ -32,6 +33,26 @@ class KonsistPreviewTest {
             }
     }
 
+    @Test
+    fun `Check functions with 'A11yPreview'`() {
+        Konsist
+            .scopeFromProject()
+            .functions()
+            .withNameEndingWith("A11yPreview")
+            .assertTrue(
+                additionalMessage = "Functions with 'A11yPreview' suffix should have '@Preview' annotation and not '@PreviewsDayNight'," +
+                    " should contain 'ElementPreview' composable," +
+                    " should contain the tested view" +
+                    " and should be internal."
+            ) {
+                val testedView = it.name.removeSuffix("A11yPreview")
+                it.text.contains("$testedView(") &&
+                    it.hasAllAnnotationsOf(PreviewsDayNight::class).not() &&
+                    it.text.contains("ElementPreview") &&
+                    it.hasInternalModifier
+            }
+    }
+
     @Test
     fun `Functions with '@PreviewsDayNight' annotation should contain 'ElementPreview' composable`() {
         Konsist

tests/uitests/src/test/kotlin/base/ComposablePreviewProvider.kt

@@ -29,13 +29,26 @@ object ComposablePreviewProvider : TestParameter.TestParameterValuesProvider {
         AndroidComposablePreviewScanner()
             .scanPackageTrees(*PACKAGE_TREES)
             .getPreviews()
+            .filter { composablePreview -> composablePreview.methodName.endsWith("A11yPreview").not() }
             .withIndex()
             .toList()
     }
 
     override fun provideValues(): List<IndexedValue<ComposablePreview<AndroidPreviewInfo>>> = values
 }
 
+object ComposableA11yPreviewProvider : TestParameter.TestParameterValuesProvider {
+    private val values: List<ComposablePreview<AndroidPreviewInfo>> by lazy {
+        AndroidComposablePreviewScanner()
+            .scanPackageTrees(*PACKAGE_TREES)
+            .getPreviews()
+            .filter { composablePreview -> composablePreview.methodName.endsWith("A11yPreview") }
+            .toList()
+    }
+
+    override fun provideValues(): List<ComposablePreview<AndroidPreviewInfo>> = values
+}
+
 object Shard1ComposablePreviewProvider : TestParameter.TestParameterValuesProvider {
     override fun provideValues(): List<ComposablePreview<AndroidPreviewInfo>> =
         ComposablePreviewProvider.provideValues().filter { it.index % 4 == 0 }.map { it.value }

tests/uitests/src/test/kotlin/base/ScreenshotTest.kt

@@ -19,6 +19,7 @@ import androidx.compose.ui.platform.LocalInspectionMode
 import androidx.compose.ui.unit.Density
 import app.cash.paparazzi.DeviceConfig
 import app.cash.paparazzi.Paparazzi
+import app.cash.paparazzi.RenderExtension
 import app.cash.paparazzi.TestName
 import com.android.resources.NightMode
 import io.element.android.compound.theme.ElementTheme
@@ -112,7 +113,12 @@ fun createScreenshotIdFor(preview: ComposablePreview<AndroidPreviewInfo>) = buil
 }.joinToString("_")
 
 object PaparazziPreviewRule {
-    fun createFor(preview: ComposablePreview<AndroidPreviewInfo>, locale: String, deviceConfig: DeviceConfig = ScreenshotTest.defaultDeviceConfig): Paparazzi {
+    fun createFor(
+        preview: ComposablePreview<AndroidPreviewInfo>,
+        locale: String,
+        deviceConfig: DeviceConfig = ScreenshotTest.defaultDeviceConfig,
+        renderExtensions: Set<RenderExtension> = setOf(),
+    ): Paparazzi {
         val densityScale = deviceConfig.density.dpiValue / 160f
         val customScreenHeight = preview.previewInfo.heightDp.takeIf { it >= 0 }?.let { it * densityScale }?.toInt()
         return Paparazzi(
@@ -125,7 +131,8 @@ object PaparazziPreviewRule {
                 softButtons = false,
                 screenHeight = customScreenHeight ?: deviceConfig.screenHeight,
             ),
-            maxPercentDifference = 0.01
+            maxPercentDifference = 0.01,
+            renderExtensions = renderExtensions,
         )
     }
 }

tests/uitests/src/test/kotlin/ui/PreviewA11yTest.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package ui
+
+import app.cash.paparazzi.accessibility.AccessibilityRenderExtension
+import base.ComposableA11yPreviewProvider
+import base.PaparazziPreviewRule
+import base.ScreenshotTest
+import com.google.testing.junit.testparameterinjector.TestParameter
+import com.google.testing.junit.testparameterinjector.TestParameterInjector
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import sergio.sastre.composable.preview.scanner.android.AndroidPreviewInfo
+import sergio.sastre.composable.preview.scanner.core.preview.ComposablePreview
+
+/**
+ * Test that takes a preview and runs a screenshot test on it.
+ * It uses [ComposableA11yPreviewProvider] to test only previews that ends with "A11yPreview".
+ */
+@RunWith(TestParameterInjector::class)
+class PreviewA11yTest(
+    @TestParameter(valuesProvider = ComposableA11yPreviewProvider::class)
+    val preview: ComposablePreview<AndroidPreviewInfo>,
+) {
+    @get:Rule
+    val paparazziRule = PaparazziPreviewRule.createFor(
+        preview = preview,
+        locale = "en",
+        renderExtensions = setOf(AccessibilityRenderExtension()),
+    )
+
+    @Test
+    fun snapshot() {
+        ScreenshotTest.runTest(paparazzi = paparazziRule, preview = preview, localeStr = "en")
+    }
+}