Move Previews to screenshotTest directory and apply compose-screenshot test plugin

app/src/main/kotlin/com/google/samples/apps/nowinandroid/ui/NiaAppState.kt

@@ -183,7 +183,7 @@ class NiaAppState(
  * Stores information about navigation events to be used with JankStats
  */
 @Composable
-private fun NavigationTrackingSideEffect(navController: NavHostController) {
+internal fun NavigationTrackingSideEffect(navController: NavHostController) {
     TrackDisposableJank(navController) { metricsHolder ->
         val listener = NavController.OnDestinationChangedListener { _, destination, _ ->
             metricsHolder.state?.putState("Navigation", destination.route.toString())

build-logic/convention/src/main/kotlin/AndroidApplicationComposeConventionPlugin.kt

@@ -16,6 +16,7 @@
 
 import com.android.build.api.dsl.ApplicationExtension
 import com.google.samples.apps.nowinandroid.configureAndroidCompose
+import com.google.samples.apps.nowinandroid.configureAndroidComposeScreenshotTest
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.kotlin.dsl.apply
@@ -26,9 +27,11 @@ class AndroidApplicationComposeConventionPlugin : Plugin<Project> {
         with(target) {
             apply(plugin = "com.android.application")
             apply(plugin = "org.jetbrains.kotlin.plugin.compose")
+            apply(plugin = "com.android.compose.screenshot")
 
             val extension = extensions.getByType<ApplicationExtension>()
             configureAndroidCompose(extension)
+            configureAndroidComposeScreenshotTest(extension)
         }
     }
 

build-logic/convention/src/main/kotlin/AndroidLibraryComposeConventionPlugin.kt

@@ -16,6 +16,7 @@
 
 import com.android.build.gradle.LibraryExtension
 import com.google.samples.apps.nowinandroid.configureAndroidCompose
+import com.google.samples.apps.nowinandroid.configureAndroidComposeScreenshotTest
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.kotlin.dsl.apply
@@ -26,9 +27,11 @@ class AndroidLibraryComposeConventionPlugin : Plugin<Project> {
         with(target) {
             apply(plugin = "com.android.library")
             apply(plugin = "org.jetbrains.kotlin.plugin.compose")
+            apply(plugin = "com.android.compose.screenshot")
 
             val extension = extensions.getByType<LibraryExtension>()
             configureAndroidCompose(extension)
+            configureAndroidComposeScreenshotTest(extension)
         }
     }
 

build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/AndroidComposeScreenshotTest.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid
+
+import com.android.build.api.dsl.CommonExtension
+import org.gradle.api.Project
+
+/**
+ * Configure project to enable compose screenshot test.
+ */
+internal fun Project.configureAndroidComposeScreenshotTest(
+    commonExtension: CommonExtension<*, *, *, *, *, *>,
+) {
+    commonExtension.apply {
+        experimentalProperties["android.experimental.enableScreenshotTest"] = true
+    }
+}

build.gradle.kts

@@ -49,6 +49,7 @@ plugins {
     alias(libs.plugins.android.test) apply false
     alias(libs.plugins.baselineprofile) apply false
     alias(libs.plugins.compose) apply false
+    alias(libs.plugins.compose.screenshot.test) apply false
     alias(libs.plugins.kotlin.jvm) apply false
     alias(libs.plugins.kotlin.serialization) apply false
     alias(libs.plugins.dependencyGuard) apply false

core/designsystem/src/main/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/Background.kt

@@ -19,7 +19,6 @@ package com.google.samples.apps.nowinandroid.core.designsystem.component
 import android.content.res.Configuration
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.size
 import androidx.compose.material3.LocalAbsoluteTonalElevation
 import androidx.compose.material3.Surface
 import androidx.compose.runtime.Composable
@@ -37,7 +36,6 @@ import androidx.compose.ui.unit.dp
 import com.google.samples.apps.nowinandroid.core.designsystem.theme.GradientColors
 import com.google.samples.apps.nowinandroid.core.designsystem.theme.LocalBackgroundTheme
 import com.google.samples.apps.nowinandroid.core.designsystem.theme.LocalGradientColors
-import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
 import kotlin.math.tan
 
 /**
@@ -146,51 +144,3 @@ fun NiaGradientBackground(
 @Preview(uiMode = Configuration.UI_MODE_NIGHT_NO, name = "Light theme")
 @Preview(uiMode = Configuration.UI_MODE_NIGHT_YES, name = "Dark theme")
 annotation class ThemePreviews
-
-@ThemePreviews
-@Composable
-fun BackgroundDefault() {
-    NiaTheme(disableDynamicTheming = true) {
-        NiaBackground(Modifier.size(100.dp), content = {})
-    }
-}
-
-@ThemePreviews
-@Composable
-fun BackgroundDynamic() {
-    NiaTheme(disableDynamicTheming = false) {
-        NiaBackground(Modifier.size(100.dp), content = {})
-    }
-}
-
-@ThemePreviews
-@Composable
-fun BackgroundAndroid() {
-    NiaTheme(androidTheme = true) {
-        NiaBackground(Modifier.size(100.dp), content = {})
-    }
-}
-
-@ThemePreviews
-@Composable
-fun GradientBackgroundDefault() {
-    NiaTheme(disableDynamicTheming = true) {
-        NiaGradientBackground(Modifier.size(100.dp), content = {})
-    }
-}
-
-@ThemePreviews
-@Composable
-fun GradientBackgroundDynamic() {
-    NiaTheme(disableDynamicTheming = false) {
-        NiaGradientBackground(Modifier.size(100.dp), content = {})
-    }
-}
-
-@ThemePreviews
-@Composable
-fun GradientBackgroundAndroid() {
-    NiaTheme(androidTheme = true) {
-        NiaGradientBackground(Modifier.size(100.dp), content = {})
-    }
-}

core/designsystem/src/main/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/Button.kt

@@ -242,7 +242,7 @@ fun NiaTextButton(
  * @param leadingIcon The button leading icon content. Default is `null` for no leading icon.Ï
  */
 @Composable
-private fun NiaButtonContent(
+internal fun NiaButtonContent(
     text: @Composable () -> Unit,
     leadingIcon: @Composable (() -> Unit)? = null,
 ) {

core/designsystem/src/main/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/TopAppBar.kt

@@ -32,9 +32,6 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.tooling.preview.Preview
-import com.google.samples.apps.nowinandroid.core.designsystem.icon.NiaIcons
-import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -73,18 +70,3 @@ fun NiaTopAppBar(
         modifier = modifier.testTag("niaTopAppBar"),
     )
 }
-
-@OptIn(ExperimentalMaterial3Api::class)
-@Preview("Top App Bar")
-@Composable
-private fun NiaTopAppBarPreview() {
-    NiaTheme {
-        NiaTopAppBar(
-            titleRes = android.R.string.untitled,
-            navigationIcon = NiaIcons.Search,
-            navigationIconContentDescription = "Navigation icon",
-            actionIcon = NiaIcons.MoreVert,
-            actionIconContentDescription = "Action icon",
-        )
-    }
-}

core/designsystem/src/main/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/ViewToggle.kt

@@ -24,15 +24,11 @@ import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ProvideTextStyle
-import androidx.compose.material3.Surface
-import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.google.samples.apps.nowinandroid.core.designsystem.icon.NiaIcons
-import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
 
 /**
  * Now in Android view toggle button with included trailing icon as well as compact and expanded
@@ -84,7 +80,7 @@ fun NiaViewToggleButton(
  * @param trailingIcon The button trailing icon content. Default is `null` for no trailing icon.
  */
 @Composable
-private fun NiaViewToggleButtonContent(
+internal fun NiaViewToggleButtonContent(
     text: @Composable () -> Unit,
     trailingIcon: @Composable (() -> Unit)? = null,
 ) {
@@ -109,36 +105,6 @@ private fun NiaViewToggleButtonContent(
     }
 }
 
-@ThemePreviews
-@Composable
-fun ViewTogglePreviewExpanded() {
-    NiaTheme {
-        Surface {
-            NiaViewToggleButton(
-                expanded = true,
-                onExpandedChange = { },
-                compactText = { Text(text = "Compact view") },
-                expandedText = { Text(text = "Expanded view") },
-            )
-        }
-    }
-}
-
-@Preview
-@Composable
-fun ViewTogglePreviewCompact() {
-    NiaTheme {
-        Surface {
-            NiaViewToggleButton(
-                expanded = false,
-                onExpandedChange = { },
-                compactText = { Text(text = "Compact view") },
-                expandedText = { Text(text = "Expanded view") },
-            )
-        }
-    }
-}
-
 /**
  * Now in Android view toggle default values.
  */

core/designsystem/src/main/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/scrollbar/AppScrollbars.kt

@@ -128,7 +128,7 @@ fun ScrollableState.DecorativeScrollbar(
  * A scrollbar thumb that is intended to also be a touch target for fast scrolling.
  */
 @Composable
-private fun ScrollableState.DraggableScrollbarThumb(
+internal fun ScrollableState.DraggableScrollbarThumb(
     interactionSource: InteractionSource,
     orientation: Orientation,
 ) {
@@ -148,7 +148,7 @@ private fun ScrollableState.DraggableScrollbarThumb(
  * A decorative scrollbar thumb used solely for communicating a user's position in a list.
  */
 @Composable
-private fun ScrollableState.DecorativeScrollbarThumb(
+internal fun ScrollableState.DecorativeScrollbarThumb(
     interactionSource: InteractionSource,
     orientation: Orientation,
 ) {
@@ -168,7 +168,7 @@ private fun ScrollableState.DecorativeScrollbarThumb(
 // remove when project is upgraded
 @SuppressLint("ComposableModifierFactory")
 @Composable
-private fun Modifier.scrollThumb(
+internal fun Modifier.scrollThumb(
     scrollableState: ScrollableState,
     interactionSource: InteractionSource,
 ): Modifier {
@@ -214,7 +214,7 @@ private class ScrollThumbNode(var colorProducer: ColorProducer) : DrawModifierNo
  * @param interactionSource source of interactions in the scrolling container
  */
 @Composable
-private fun scrollbarThumbColor(
+internal fun scrollbarThumbColor(
     scrollableState: ScrollableState,
     interactionSource: InteractionSource,
 ): State<Color> {

core/designsystem/src/main/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/scrollbar/ThumbExt.kt

@@ -71,7 +71,7 @@ fun LazyStaggeredGridState.rememberDraggableScroller(
  * @param scroll a function to be invoked when an index has been identified to scroll to.
  */
 @Composable
-private inline fun rememberDraggableScroller(
+internal inline fun rememberDraggableScroller(
     itemsAvailable: Int,
     crossinline scroll: suspend (index: Int) -> Unit,
 ): (Float) -> Unit {

core/designsystem/src/screenshotTest/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/BackgroundScreenshotTest.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.core.designsystem.component
+import androidx.compose.foundation.layout.size
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+
+@ThemePreviews
+@Composable
+fun BackgroundDefault() {
+    NiaTheme(disableDynamicTheming = true) {
+        NiaBackground(Modifier.size(100.dp), content = {})
+    }
+}
+
+@ThemePreviews
+@Composable
+fun BackgroundDynamic() {
+    NiaTheme(disableDynamicTheming = false) {
+        NiaBackground(Modifier.size(100.dp), content = {})
+    }
+}
+
+@ThemePreviews
+@Composable
+fun BackgroundAndroid() {
+    NiaTheme(androidTheme = true) {
+        NiaBackground(Modifier.size(100.dp), content = {})
+    }
+}
+
+@ThemePreviews
+@Composable
+fun GradientBackgroundDefault() {
+    NiaTheme(disableDynamicTheming = true) {
+        NiaGradientBackground(Modifier.size(100.dp), content = {})
+    }
+}
+
+@ThemePreviews
+@Composable
+fun GradientBackgroundDynamic() {
+    NiaTheme(disableDynamicTheming = false) {
+        NiaGradientBackground(Modifier.size(100.dp), content = {})
+    }
+}
+
+@ThemePreviews
+@Composable
+fun GradientBackgroundAndroid() {
+    NiaTheme(androidTheme = true) {
+        NiaGradientBackground(Modifier.size(100.dp), content = {})
+    }
+}

core/designsystem/src/screenshotTest/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/TopAppBarScreenshotTest.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.core.designsystem.component
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.tooling.preview.Preview
+import com.google.samples.apps.nowinandroid.core.designsystem.icon.NiaIcons
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Preview("Top App Bar")
+@Composable
+fun NiaTopAppBarPreview() {
+    NiaTheme {
+        NiaTopAppBar(
+            titleRes = android.R.string.untitled,
+            navigationIcon = NiaIcons.Search,
+            navigationIconContentDescription = "Navigation icon",
+            actionIcon = NiaIcons.MoreVert,
+            actionIconContentDescription = "Action icon",
+        )
+    }
+}

core/designsystem/src/screenshotTest/kotlin/com/google/samples/apps/nowinandroid/core/designsystem/component/ViewToggleScreenshotTest.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.core.designsystem.component
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.tooling.preview.Preview
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+
+@ThemePreviews
+@Composable
+fun ViewTogglePreviewExpanded() {
+    NiaTheme {
+        Surface {
+            NiaViewToggleButton(
+                expanded = true,
+                onExpandedChange = { },
+                compactText = { Text(text = "Compact view") },
+                expandedText = { Text(text = "Expanded view") },
+            )
+        }
+    }
+}
+
+@Preview
+@Composable
+fun ViewTogglePreviewCompact() {
+    NiaTheme {
+        Surface {
+            NiaViewToggleButton(
+                expanded = false,
+                onExpandedChange = { },
+                compactText = { Text(text = "Compact view") },
+                expandedText = { Text(text = "Expanded view") },
+            )
+        }
+    }
+}

core/screenshot-testing/src/main/kotlin/com/google/samples/apps/nowinandroid/core/testing/util/ScreenshotHelper.kt

@@ -228,7 +228,7 @@ fun <A : ComponentActivity> AndroidComposeTestRule<ActivityScenarioRule<A>, A>.c
 }
 
 @Composable
-private fun generateDescription(
+internal fun generateDescription(
     shouldCompareDarkMode: Boolean,
     darkMode: Boolean,
     shouldCompareAndroidTheme: Boolean,

core/ui/src/main/kotlin/com/google/samples/apps/nowinandroid/core/ui/InterestsItem.kt

@@ -24,7 +24,6 @@ import androidx.compose.material3.Icon
 import androidx.compose.material3.ListItem
 import androidx.compose.material3.ListItemDefaults
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
@@ -32,12 +31,10 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.selected
 import androidx.compose.ui.semantics.semantics
-import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.google.samples.apps.nowinandroid.core.designsystem.component.DynamicAsyncImage
 import com.google.samples.apps.nowinandroid.core.designsystem.component.NiaIconToggleButton
 import com.google.samples.apps.nowinandroid.core.designsystem.icon.NiaIcons
-import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
 import com.google.samples.apps.nowinandroid.core.ui.R.string
 
 @Composable
@@ -100,7 +97,7 @@ fun InterestsItem(
 }
 
 @Composable
-private fun InterestsIcon(topicImageUrl: String, modifier: Modifier = Modifier) {
+internal fun InterestsIcon(topicImageUrl: String, modifier: Modifier = Modifier) {
     if (topicImageUrl.isEmpty()) {
         Icon(
             modifier = modifier
@@ -118,90 +115,3 @@ private fun InterestsIcon(topicImageUrl: String, modifier: Modifier = Modifier)
         )
     }
 }
-
-@Preview
-@Composable
-private fun InterestsCardPreview() {
-    NiaTheme {
-        Surface {
-            InterestsItem(
-                name = "Compose",
-                description = "Description",
-                following = false,
-                topicImageUrl = "",
-                onClick = { },
-                onFollowButtonClick = { },
-            )
-        }
-    }
-}
-
-@Preview
-@Composable
-private fun InterestsCardLongNamePreview() {
-    NiaTheme {
-        Surface {
-            InterestsItem(
-                name = "This is a very very very very long name",
-                description = "Description",
-                following = true,
-                topicImageUrl = "",
-                onClick = { },
-                onFollowButtonClick = { },
-            )
-        }
-    }
-}
-
-@Preview
-@Composable
-private fun InterestsCardLongDescriptionPreview() {
-    NiaTheme {
-        Surface {
-            InterestsItem(
-                name = "Compose",
-                description = "This is a very very very very very very very " +
-                    "very very very long description",
-                following = false,
-                topicImageUrl = "",
-                onClick = { },
-                onFollowButtonClick = { },
-            )
-        }
-    }
-}
-
-@Preview
-@Composable
-private fun InterestsCardWithEmptyDescriptionPreview() {
-    NiaTheme {
-        Surface {
-            InterestsItem(
-                name = "Compose",
-                description = "",
-                following = true,
-                topicImageUrl = "",
-                onClick = { },
-                onFollowButtonClick = { },
-            )
-        }
-    }
-}
-
-@Preview
-@Composable
-private fun InterestsCardSelectedPreview() {
-    NiaTheme {
-        Surface {
-            InterestsItem(
-                name = "Compose",
-                description = "",
-                following = true,
-                topicImageUrl = "",
-                onClick = { },
-                onFollowButtonClick = { },
-                isSelected = true,
-            )
-        }
-    }
-}

core/ui/src/main/kotlin/com/google/samples/apps/nowinandroid/core/ui/NewsFeed.kt

@@ -24,20 +24,13 @@ import androidx.browser.customtabs.CustomTabsIntent
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyListScope
 import androidx.compose.foundation.lazy.staggeredgrid.LazyStaggeredGridScope
-import androidx.compose.foundation.lazy.staggeredgrid.LazyVerticalStaggeredGrid
-import androidx.compose.foundation.lazy.staggeredgrid.StaggeredGridCells
 import androidx.compose.foundation.lazy.staggeredgrid.items
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.toArgb
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.tooling.preview.Devices
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.compose.ui.tooling.preview.PreviewParameter
 import androidx.compose.ui.unit.dp
 import com.google.samples.apps.nowinandroid.core.analytics.LocalAnalyticsHelper
-import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
 import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
 
 /**
@@ -121,37 +114,3 @@ sealed interface NewsFeedUiState {
         val feed: List<UserNewsResource>,
     ) : NewsFeedUiState
 }
-
-@Preview
-@Composable
-private fun NewsFeedLoadingPreview() {
-    NiaTheme {
-        LazyVerticalStaggeredGrid(columns = StaggeredGridCells.Adaptive(300.dp)) {
-            newsFeed(
-                feedState = NewsFeedUiState.Loading,
-                onNewsResourcesCheckedChanged = { _, _ -> },
-                onNewsResourceViewed = {},
-                onTopicClick = {},
-            )
-        }
-    }
-}
-
-@Preview
-@Preview(device = Devices.TABLET)
-@Composable
-private fun NewsFeedContentPreview(
-    @PreviewParameter(UserNewsResourcePreviewParameterProvider::class)
-    userNewsResources: List<UserNewsResource>,
-) {
-    NiaTheme {
-        LazyVerticalStaggeredGrid(columns = StaggeredGridCells.Adaptive(300.dp)) {
-            newsFeed(
-                feedState = NewsFeedUiState.Success(userNewsResources),
-                onNewsResourcesCheckedChanged = { _, _ -> },
-                onNewsResourceViewed = {},
-                onTopicClick = {},
-            )
-        }
-    }
-}

core/ui/src/main/kotlin/com/google/samples/apps/nowinandroid/core/ui/NewsResourceCard.kt

@@ -42,10 +42,8 @@ import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -62,8 +60,6 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.onClick
 import androidx.compose.ui.semantics.semantics
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.compose.ui.tooling.preview.PreviewParameter
 import androidx.compose.ui.unit.dp
 import coil.compose.AsyncImagePainter
 import coil.compose.rememberAsyncImagePainter
@@ -71,7 +67,6 @@ import com.google.samples.apps.nowinandroid.core.designsystem.R.drawable
 import com.google.samples.apps.nowinandroid.core.designsystem.component.NiaIconToggleButton
 import com.google.samples.apps.nowinandroid.core.designsystem.component.NiaTopicTag
 import com.google.samples.apps.nowinandroid.core.designsystem.icon.NiaIcons
-import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
 import com.google.samples.apps.nowinandroid.core.model.data.FollowableTopic
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
 import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
@@ -350,47 +345,3 @@ fun NewsResourceTopics(
         }
     }
 }
-
-@Preview("Bookmark Button")
-@Composable
-private fun BookmarkButtonPreview() {
-    NiaTheme {
-        Surface {
-            BookmarkButton(isBookmarked = false, onClick = { })
-        }
-    }
-}
-
-@Preview("Bookmark Button Bookmarked")
-@Composable
-private fun BookmarkButtonBookmarkedPreview() {
-    NiaTheme {
-        Surface {
-            BookmarkButton(isBookmarked = true, onClick = { })
-        }
-    }
-}
-
-@Preview("NewsResourceCardExpanded")
-@Composable
-private fun ExpandedNewsResourcePreview(
-    @PreviewParameter(UserNewsResourcePreviewParameterProvider::class)
-    userNewsResources: List<UserNewsResource>,
-) {
-    CompositionLocalProvider(
-        LocalInspectionMode provides true,
-    ) {
-        NiaTheme {
-            Surface {
-                NewsResourceCardExpanded(
-                    userNewsResource = userNewsResources[0],
-                    isBookmarked = true,
-                    hasBeenViewed = false,
-                    onToggleBookmark = {},
-                    onClick = {},
-                    onTopicClick = {},
-                )
-            }
-        }
-    }
-}

core/ui/src/screenshotTest/kotlin/com/google/samples/apps/nowinandroid/core/ui/InterestsItemScreenshotTest.kt

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.core.ui
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.tooling.preview.Preview
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+
+@Preview
+@Composable
+fun InterestsCardPreview() {
+    NiaTheme {
+        Surface {
+            InterestsItem(
+                name = "Compose",
+                description = "Description",
+                following = false,
+                topicImageUrl = "",
+                onClick = { },
+                onFollowButtonClick = { },
+            )
+        }
+    }
+}
+
+@Preview
+@Composable
+fun InterestsCardLongNamePreview() {
+    NiaTheme {
+        Surface {
+            InterestsItem(
+                name = "This is a very very very very long name",
+                description = "Description",
+                following = true,
+                topicImageUrl = "",
+                onClick = { },
+                onFollowButtonClick = { },
+            )
+        }
+    }
+}
+
+@Preview
+@Composable
+fun InterestsCardLongDescriptionPreview() {
+    NiaTheme {
+        Surface {
+            InterestsItem(
+                name = "Compose",
+                description = "This is a very very very very very very very " +
+                    "very very very long description",
+                following = false,
+                topicImageUrl = "",
+                onClick = { },
+                onFollowButtonClick = { },
+            )
+        }
+    }
+}
+
+@Preview
+@Composable
+fun InterestsCardWithEmptyDescriptionPreview() {
+    NiaTheme {
+        Surface {
+            InterestsItem(
+                name = "Compose",
+                description = "",
+                following = true,
+                topicImageUrl = "",
+                onClick = { },
+                onFollowButtonClick = { },
+            )
+        }
+    }
+}
+
+@Preview
+@Composable
+fun InterestsCardSelectedPreview() {
+    NiaTheme {
+        Surface {
+            InterestsItem(
+                name = "Compose",
+                description = "",
+                following = true,
+                topicImageUrl = "",
+                onClick = { },
+                onFollowButtonClick = { },
+                isSelected = true,
+            )
+        }
+    }
+}

core/ui/src/screenshotTest/kotlin/com/google/samples/apps/nowinandroid/core/ui/NewsFeedScreenshotTest.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.core.ui
+import androidx.compose.foundation.lazy.staggeredgrid.LazyVerticalStaggeredGrid
+import androidx.compose.foundation.lazy.staggeredgrid.StaggeredGridCells
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.tooling.preview.Devices
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.tooling.preview.PreviewParameter
+import androidx.compose.ui.unit.dp
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
+
+@Preview
+@Composable
+fun NewsFeedLoadingPreview() {
+    NiaTheme {
+        LazyVerticalStaggeredGrid(columns = StaggeredGridCells.Adaptive(300.dp)) {
+            newsFeed(
+                feedState = NewsFeedUiState.Loading,
+                onNewsResourcesCheckedChanged = { _, _ -> },
+                onNewsResourceViewed = {},
+                onTopicClick = {},
+            )
+        }
+    }
+}
+
+@Preview
+@Preview(device = Devices.TABLET)
+@Composable
+fun NewsFeedContentPreview(
+    @PreviewParameter(UserNewsResourcePreviewParameterProvider::class)
+    userNewsResources: List<UserNewsResource>,
+) {
+    NiaTheme {
+        LazyVerticalStaggeredGrid(columns = StaggeredGridCells.Adaptive(300.dp)) {
+            newsFeed(
+                feedState = NewsFeedUiState.Success(userNewsResources),
+                onNewsResourcesCheckedChanged = { _, _ -> },
+                onNewsResourceViewed = {},
+                onTopicClick = {},
+            )
+        }
+    }
+}

core/ui/src/screenshotTest/kotlin/com/google/samples/apps/nowinandroid/core/ui/NewsResourceCardScreenshotTest.kt

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.core.ui
+import androidx.compose.material3.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.platform.LocalInspectionMode
+import androidx.compose.ui.semantics.onClick
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.tooling.preview.PreviewParameter
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
+
+@Preview("Bookmark Button")
+@Composable
+fun BookmarkButtonPreview() {
+    NiaTheme {
+        Surface {
+            BookmarkButton(isBookmarked = false, onClick = { })
+        }
+    }
+}
+
+@Preview("Bookmark Button Bookmarked")
+@Composable
+fun BookmarkButtonBookmarkedPreview() {
+    NiaTheme {
+        Surface {
+            BookmarkButton(isBookmarked = true, onClick = { })
+        }
+    }
+}
+
+@Preview("NewsResourceCardExpanded")
+@Composable
+fun ExpandedNewsResourcePreview(
+    @PreviewParameter(UserNewsResourcePreviewParameterProvider::class)
+    userNewsResources: List<UserNewsResource>,
+) {
+    CompositionLocalProvider(
+        LocalInspectionMode provides true,
+    ) {
+        NiaTheme {
+            Surface {
+                NewsResourceCardExpanded(
+                    userNewsResource = userNewsResources[0],
+                    isBookmarked = true,
+                    hasBeenViewed = false,
+                    onToggleBookmark = {},
+                    onClick = {},
+                    onTopicClick = {},
+                )
+            }
+        }
+    }
+}

feature/bookmarks/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/bookmarks/BookmarksScreen.kt

@@ -53,8 +53,6 @@ import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.compose.ui.tooling.preview.PreviewParameter
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.Lifecycle
@@ -65,14 +63,11 @@ import com.google.samples.apps.nowinandroid.core.designsystem.component.scrollba
 import com.google.samples.apps.nowinandroid.core.designsystem.component.scrollbar.rememberDraggableScroller
 import com.google.samples.apps.nowinandroid.core.designsystem.component.scrollbar.scrollbarState
 import com.google.samples.apps.nowinandroid.core.designsystem.theme.LocalTintTheme
-import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
-import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
 import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState
 import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState.Loading
 import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState.Success
 import com.google.samples.apps.nowinandroid.core.ui.TrackScreenViewEvent
 import com.google.samples.apps.nowinandroid.core.ui.TrackScrollJank
-import com.google.samples.apps.nowinandroid.core.ui.UserNewsResourcePreviewParameterProvider
 import com.google.samples.apps.nowinandroid.core.ui.newsFeed
 
 @Composable
@@ -149,7 +144,7 @@ internal fun BookmarksScreen(
 }
 
 @Composable
-private fun LoadingState(modifier: Modifier = Modifier) {
+internal fun LoadingState(modifier: Modifier = Modifier) {
     NiaLoadingWheel(
         modifier = modifier
             .fillMaxWidth()
@@ -160,7 +155,7 @@ private fun LoadingState(modifier: Modifier = Modifier) {
 }
 
 @Composable
-private fun BookmarksGrid(
+internal fun BookmarksGrid(
     feedState: NewsFeedUiState,
     removeFromBookmarks: (String) -> Unit,
     onNewsResourceViewed: (String) -> Unit,
@@ -216,7 +211,7 @@ private fun BookmarksGrid(
 }
 
 @Composable
-private fun EmptyState(modifier: Modifier = Modifier) {
+internal fun EmptyState(modifier: Modifier = Modifier) {
     Column(
         modifier = modifier
             .padding(16.dp)
@@ -253,35 +248,3 @@ private fun EmptyState(modifier: Modifier = Modifier) {
         )
     }
 }
-
-@Preview
-@Composable
-private fun LoadingStatePreview() {
-    NiaTheme {
-        LoadingState()
-    }
-}
-
-@Preview
-@Composable
-private fun BookmarksGridPreview(
-    @PreviewParameter(UserNewsResourcePreviewParameterProvider::class)
-    userNewsResources: List<UserNewsResource>,
-) {
-    NiaTheme {
-        BookmarksGrid(
-            feedState = Success(userNewsResources),
-            removeFromBookmarks = {},
-            onNewsResourceViewed = {},
-            onTopicClick = {},
-        )
-    }
-}
-
-@Preview
-@Composable
-private fun EmptyStatePreview() {
-    NiaTheme {
-        EmptyState()
-    }
-}

feature/bookmarks/src/screenshotTest/kotlin/com/google/samples/apps/nowinandroid/feature/bookmarks/BookmarksScreenScreenshotTest.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.feature.bookmarks
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.tooling.preview.PreviewParameter
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
+import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState.Success
+import com.google.samples.apps.nowinandroid.core.ui.UserNewsResourcePreviewParameterProvider
+
+@Preview
+@Composable
+fun LoadingStatePreview() {
+    NiaTheme {
+        LoadingState()
+    }
+}
+
+@Preview
+@Composable
+fun BookmarksGridPreview(
+    @PreviewParameter(UserNewsResourcePreviewParameterProvider::class)
+    userNewsResources: List<UserNewsResource>,
+) {
+    NiaTheme {
+        BookmarksGrid(
+            feedState = Success(userNewsResources),
+            removeFromBookmarks = {},
+            onNewsResourceViewed = {},
+            onTopicClick = {},
+        )
+    }
+}
+
+@Preview
+@Composable
+fun EmptyStatePreview() {
+    NiaTheme {
+        EmptyState()
+    }
+}