Merge pull request #244 from ouchadam/tech/gallery-tests

Tech/Image Gallery Tests

domains/android/core/src/main/kotlin/app/dapk/st/core/ContentResolverExtensions.kt

@@ -0,0 +1,30 @@
+package app.dapk.st.core
+
+import android.content.ContentResolver
+import android.database.Cursor
+import android.net.Uri
+
+data class ContentResolverQuery(
+    val uri: Uri,
+    val projection: List<String>,
+    val selection: String,
+    val selectionArgs: List<String>,
+    val sortBy: String,
+)
+
+inline fun <T> ContentResolver.reduce(query: ContentResolverQuery, operation: (Cursor) -> T): List<T> {
+    return this.reduce(query, mutableListOf<T>()) { acc, cursor ->
+        acc.add(operation(cursor))
+        acc
+    }
+}
+
+inline fun <T> ContentResolver.reduce(query: ContentResolverQuery, initial: T, operation: (T, Cursor) -> T): T {
+    var accumulator: T = initial
+    this.query(query.uri, query.projection.toTypedArray(), query.selection, query.selectionArgs.toTypedArray(), query.sortBy).use { cursor ->
+        while (cursor != null && cursor.moveToNext()) {
+            accumulator = operation(accumulator, cursor)
+        }
+    }
+    return accumulator
+}

domains/android/stub/src/testFixtures/kotlin/fake/FakeContentResolver.kt

@@ -13,4 +13,20 @@ class FakeContentResolver {
     fun givenFile(uri: Uri) = every { instance.openInputStream(uri) }.delegateReturn()
 
     fun givenUriResult(uri: Uri) = every { instance.query(uri, null, null, null, null) }.delegateReturn()
+
+    fun givenQueryResult(
+        uri: Uri,
+        projection: Array<String>?,
+        selection: String?,
+        selectionArgs: Array<String>?,
+        sortOrder: String?,
+    ) = every {
+        instance.query(
+            uri,
+            projection,
+            selection,
+            selectionArgs,
+            sortOrder
+        )
+    }.delegateReturn()
 }

domains/android/stub/src/testFixtures/kotlin/fake/FakeCursor.kt

@@ -24,4 +24,56 @@ class FakeCursor {
         every { instance.getColumnIndex(columnName) } returns columnId
         every { instance.getString(columnId) } returns content
     }
+
+}
+
+interface CreateCursorScope {
+    fun addRow(vararg item: Pair<String, Any?>)
+}
+
+fun createCursor(creator: CreateCursorScope.() -> Unit): Cursor {
+    val content = mutableListOf<Map<String, Any?>>()
+    val scope = object : CreateCursorScope {
+        override fun addRow(vararg item: Pair<String, Any?>) {
+            content.add(item.toMap())
+        }
+    }
+    creator(scope)
+    return StubCursor(content)
+}
+
+private class StubCursor(private val content: List<Map<String, Any?>>) : Cursor by mockk() {
+
+    private val columnNames = content.map { it.keys }.flatten().distinct()
+    private var currentRowIndex = -1
+
+    override fun getColumnIndexOrThrow(columnName: String): Int {
+        return getColumnIndex(columnName).takeIf { it != -1 } ?: throw IllegalArgumentException(columnName)
+    }
+
+    override fun getColumnIndex(columnName: String) = columnNames.indexOf(columnName)
+
+    override fun moveToNext() = (currentRowIndex + 1 < content.size).also {
+        currentRowIndex += 1
+    }
+
+    override fun moveToFirst() = content.isNotEmpty()
+
+    override fun getCount() = content.size
+
+    override fun getString(index: Int): String? = content[currentRowIndex][columnNames[index]] as? String
+
+    override fun getInt(index: Int): Int {
+        return content[currentRowIndex][columnNames[index]] as? Int ?: throw IllegalArgumentException("Int can't be null")
+    }
+
+    override fun getLong(index: Int): Long {
+        return content[currentRowIndex][columnNames[index]] as? Long ?: throw IllegalArgumentException("Long can't be null")
+    }
+
+    override fun getColumnCount() = columnNames.size
+
+    override fun close() {
+        // do nothing
+    }
 }

domains/state/src/testFixtures/kotlin/test/ReducerTest.kt

@@ -39,6 +39,8 @@ class ReducerTestScope<S, E>(
     private val expectTestScope: ExpectTestScope
 ) : ExpectTestScope by expectTestScope, Reducer<S> {
 
+    private var invalidateCapturedState: Boolean = false
+    private val actionSideEffects = mutableMapOf<Action, () -> S>()
     private var manualState: S? = null
     private var capturedResult: S? = null
 
@@ -47,6 +49,10 @@ class ReducerTestScope<S, E>(
         override val coroutineScope = CoroutineScope(UnconfinedTestDispatcher())
         override fun dispatch(action: Action) {
             actionCaptures.add(action)
+
+            if (actionSideEffects.containsKey(action)) {
+                setState(actionSideEffects.getValue(action).invoke(), invalidateCapturedState = true)
+            }
         }
 
         override fun getState() = manualState ?: reducerFactory.initialState()
@@ -54,15 +60,20 @@ class ReducerTestScope<S, E>(
     private val reducer: Reducer<S> = reducerFactory.create(reducerScope)
 
     override fun reduce(action: Action) = reducer.reduce(action).also {
-        capturedResult = it
+        capturedResult = if (invalidateCapturedState) manualState else it
     }
 
-    fun setState(state: S) {
+    fun actionSideEffect(action: Action, handler: () -> S) {
+        actionSideEffects[action] = handler
+    }
+
+    fun setState(state: S, invalidateCapturedState: Boolean = false) {
         manualState = state
+        this.invalidateCapturedState = invalidateCapturedState
     }
 
     fun setState(block: (S) -> S) {
-        manualState = block(reducerScope.getState())
+        setState(block(reducerScope.getState()))
     }
 
     fun assertInitialState(expected: S) {

features/messenger/src/main/kotlin/app/dapk/st/messenger/gallery/FetchMediaFoldersUseCase.kt

@@ -1,37 +1,39 @@
 package app.dapk.st.messenger.gallery
 
 import android.content.ContentResolver
-import android.content.ContentUris
 import android.net.Uri
 import android.provider.MediaStore.Images
+import app.dapk.st.core.ContentResolverQuery
 import app.dapk.st.core.CoroutineDispatchers
+import app.dapk.st.core.reduce
 import app.dapk.st.core.withIoContext
 
 class FetchMediaFoldersUseCase(
     private val contentResolver: ContentResolver,
+    private val uriAvoidance: MediaUriAvoidance,
     private val dispatchers: CoroutineDispatchers,
 ) {
 
     suspend fun fetchFolders(): List<Folder> {
         return dispatchers.withIoContext {
-            val projection = arrayOf(Images.Media._ID, Images.Media.BUCKET_ID, Images.Media.BUCKET_DISPLAY_NAME, Images.Media.DATE_MODIFIED)
+            val query = ContentResolverQuery(
-            val selection = "${isNotPending()} AND ${Images.Media.BUCKET_ID} AND ${Images.Media.MIME_TYPE} NOT LIKE ?"
+                uriAvoidance.externalContentUri,
-            val sortBy = "${Images.Media.BUCKET_DISPLAY_NAME} COLLATE NOCASE ASC, ${Images.Media.DATE_MODIFIED} DESC"
+                listOf(Images.Media._ID, Images.Media.BUCKET_ID, Images.Media.BUCKET_DISPLAY_NAME, Images.Media.DATE_MODIFIED),
+                "${isNotPending()} AND ${Images.Media.BUCKET_ID} AND ${Images.Media.MIME_TYPE} NOT LIKE ?",
+                listOf("%image/svg%"),
+                "${Images.Media.BUCKET_DISPLAY_NAME} COLLATE NOCASE ASC, ${Images.Media.DATE_MODIFIED} DESC"
+            )
 
-            val folders = mutableMapOf<String, Folder>()
+            contentResolver.reduce(query, mutableMapOf<String, Folder>()) { acc, cursor ->
-            val contentUri = Images.Media.EXTERNAL_CONTENT_URI
+                val rowId = cursor.getLong(cursor.getColumnIndexOrThrow(Images.Media._ID))
-            contentResolver.query(contentUri, projection, selection, arrayOf("%image/svg%"), sortBy).use { cursor ->
+                val thumbnail = uriAvoidance.uriAppender(query.uri, rowId)
-                while (cursor != null && cursor.moveToNext()) {
+                val bucketId = cursor.getString(cursor.getColumnIndexOrThrow(Images.Media.BUCKET_ID))
-                    val rowId = cursor.getLong(cursor.getColumnIndexOrThrow(projection[0]))
+                val title = cursor.getString(cursor.getColumnIndexOrThrow(Images.Media.BUCKET_DISPLAY_NAME)) ?: ""
-                    val thumbnail = ContentUris.withAppendedId(contentUri, rowId)
+                val timestamp = cursor.getLong(cursor.getColumnIndexOrThrow(Images.Media.DATE_MODIFIED))
-                    val bucketId = cursor.getString(cursor.getColumnIndexOrThrow(projection[1]))
+                val folder = acc.getOrPut(bucketId) { Folder(bucketId, title, thumbnail) }
-                    val title = cursor.getString(cursor.getColumnIndexOrThrow(projection[2])) ?: ""
+                folder.incrementItemCount()
-                    val timestamp = cursor.getLong(cursor.getColumnIndexOrThrow(projection[3]))
+                acc
-                    val folder = folders.getOrPut(bucketId) { Folder(bucketId, title, thumbnail) }
+            }.values.toList()
-                    folder.incrementItemCount()
-                }
-            }
-            folders.values.toList()
         }
     }
 

features/messenger/src/main/kotlin/app/dapk/st/messenger/gallery/FetchMediaUseCase.kt

@@ -1,15 +1,20 @@
 package app.dapk.st.messenger.gallery
 
 import android.content.ContentResolver
-import android.content.ContentUris
 import android.net.Uri
 import android.provider.MediaStore
+import app.dapk.st.core.ContentResolverQuery
 import app.dapk.st.core.CoroutineDispatchers
+import app.dapk.st.core.reduce
 import app.dapk.st.core.withIoContext
 
-class FetchMediaUseCase(private val contentResolver: ContentResolver, private val dispatchers: CoroutineDispatchers) {
+class FetchMediaUseCase(
+    private val contentResolver: ContentResolver,
+    private val uriAvoidance: MediaUriAvoidance,
+    private val dispatchers: CoroutineDispatchers
+) {
 
-    private val projection = arrayOf(
+    private val projection = listOf(
         MediaStore.Images.Media._ID,
         MediaStore.Images.Media.MIME_TYPE,
         MediaStore.Images.Media.DATE_MODIFIED,
@@ -22,26 +27,26 @@ class FetchMediaUseCase(private val contentResolver: ContentResolver, private va
     private val selection = MediaStore.Images.Media.BUCKET_ID + " = ? AND " + isNotPending() + " AND " + MediaStore.Images.Media.MIME_TYPE + " NOT LIKE ?"
 
     suspend fun getMediaInBucket(bucketId: String): List<Media> {
-
         return dispatchers.withIoContext {
-            val media = mutableListOf<Media>()
+            val query = ContentResolverQuery(
-            val selectionArgs = arrayOf(bucketId, "%image/svg%")
+                uri = uriAvoidance.externalContentUri,
-            val sortBy = MediaStore.Images.Media.DATE_MODIFIED + " DESC"
+                projection = projection,
-            val contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
+                selection = selection,
-            contentResolver.query(contentUri, projection, selection, selectionArgs, sortBy).use { cursor ->
+                selectionArgs = listOf(bucketId, "%image/svg%"),
-                while (cursor != null && cursor.moveToNext()) {
+                sortBy = MediaStore.Images.Media.DATE_MODIFIED + " DESC",
-                    val rowId = cursor.getLong(cursor.getColumnIndexOrThrow(projection[0]))
+            )
-                    val uri = ContentUris.withAppendedId(contentUri, rowId)
+
-                    val mimetype = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.MIME_TYPE))
+            contentResolver.reduce(query) { cursor ->
-                    val date = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATE_MODIFIED))
+                val rowId = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID))
-                    val orientation = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.ORIENTATION))
+                val uri = uriAvoidance.uriAppender(query.uri, rowId)
-                    val width = cursor.getInt(cursor.getColumnIndexOrThrow(getWidthColumn(orientation)))
+                val mimetype = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.MIME_TYPE))
-                    val height = cursor.getInt(cursor.getColumnIndexOrThrow(getHeightColumn(orientation)))
+                val date = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATE_MODIFIED))
-                    val size = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE))
+                val orientation = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.ORIENTATION))
-                    media.add(Media(rowId, uri, mimetype, width, height, size, date))
+                val width = cursor.getInt(cursor.getColumnIndexOrThrow(getWidthColumn(orientation)))
-                }
+                val height = cursor.getInt(cursor.getColumnIndexOrThrow(getHeightColumn(orientation)))
+                val size = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE))
+                Media(rowId, uri, mimetype, width, height, size, date)
             }
-            media
         }
     }
 
@@ -49,7 +54,6 @@ class FetchMediaUseCase(private val contentResolver: ContentResolver, private va
 
     private fun getHeightColumn(orientation: Int) =
         if (orientation == 0 || orientation == 180) MediaStore.Images.Media.HEIGHT else MediaStore.Images.Media.WIDTH
-
 }
 
 data class Media(

features/messenger/src/main/kotlin/app/dapk/st/messenger/gallery/ImageGalleryModule.kt

@@ -1,7 +1,12 @@
 package app.dapk.st.messenger.gallery
 
 import android.content.ContentResolver
-import app.dapk.st.core.*
+import android.content.ContentUris
+import android.provider.MediaStore
+import app.dapk.st.core.CoroutineDispatchers
+import app.dapk.st.core.JobBag
+import app.dapk.st.core.ProvidableModule
+import app.dapk.st.core.createStateViewModel
 import app.dapk.st.messenger.gallery.state.ImageGalleryState
 import app.dapk.st.messenger.gallery.state.imageGalleryReducer
 
@@ -11,10 +16,14 @@ class ImageGalleryModule(
 ) : ProvidableModule {
 
     fun imageGalleryState(roomName: String): ImageGalleryState = createStateViewModel {
+        val uriAvoidance = MediaUriAvoidance(
+            uriAppender = { uri, rowId -> ContentUris.withAppendedId(uri, rowId) },
+            externalContentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
+        )
         imageGalleryReducer(
             roomName = roomName,
-            FetchMediaFoldersUseCase(contentResolver, dispatchers),
+            FetchMediaFoldersUseCase(contentResolver, uriAvoidance, dispatchers),
-            FetchMediaUseCase(contentResolver, dispatchers),
+            FetchMediaUseCase(contentResolver, uriAvoidance, dispatchers),
             JobBag(),
         )
     }

features/messenger/src/main/kotlin/app/dapk/st/messenger/gallery/MediaUriAvoidance.kt

@@ -0,0 +1,8 @@
+package app.dapk.st.messenger.gallery
+
+import android.net.Uri
+
+class MediaUriAvoidance(
+    val uriAppender: (Uri, Long) -> Uri,
+    val externalContentUri: Uri,
+)

features/messenger/src/main/kotlin/app/dapk/st/messenger/gallery/state/ImageGalleryReducer.kt

@@ -46,7 +46,6 @@ fun imageGalleryReducer(
                     parent = ImageGalleryPage.Routes.folders,
                     state = ImageGalleryPage.Files(Lce.Loading(), action.folder)
                 )
-
                 dispatch(PageAction.GoTo(page))
 
                 jobBag.replace(ImageGalleryPage.Files::class, coroutineScope.launch {
@@ -58,7 +57,7 @@ fun imageGalleryReducer(
             },
 
             sideEffect(PageStateChange.ChangePage::class) { action, _ ->
-                jobBag.cancel(action.previous::class)
+                jobBag.cancel(action.previous.state::class)
             },
         )
     }

features/messenger/src/test/kotlin/app/dapk/st/messenger/gallery/FetchMediaFoldersUseCaseTest.kt

@@ -0,0 +1,91 @@
+package app.dapk.st.messenger.gallery
+
+import android.net.Uri
+import android.provider.MediaStore
+import fake.CreateCursorScope
+import fake.FakeContentResolver
+import fake.FakeUri
+import fake.createCursor
+import fixture.CoroutineDispatchersFixture.aCoroutineDispatchers
+import kotlinx.coroutines.test.runTest
+import org.amshove.kluent.shouldBeEqualTo
+import org.junit.Test
+
+private val A_EXTERNAL_CONTENT_URI = FakeUri()
+private const val A_BUCKET_ID = "a-bucket-id"
+private const val A_SECOND_BUCKET_ID = "another-bucket"
+private const val A_DISPLAY_NAME = "a-bucket-name"
+private const val A_DATE_MODIFIED = 5000L
+
+class FetchMediaFoldersUseCaseTest {
+
+    private val fakeContentResolver = FakeContentResolver()
+    private val fakeUriAppender = FakeUriAppender()
+    private val uriAvoidance = MediaUriAvoidance(
+        uriAppender = fakeUriAppender,
+        externalContentUri = A_EXTERNAL_CONTENT_URI.instance,
+    )
+
+    private val useCase = FetchMediaFoldersUseCase(fakeContentResolver.instance, uriAvoidance, aCoroutineDispatchers())
+
+    @Test
+    fun `given cursor content, when get folder, then reads unique folders`() = runTest {
+        fakeContentResolver.givenFolderQuery().returns(createCursor {
+            addFolderRow(rowId = 1, A_BUCKET_ID)
+            addFolderRow(rowId = 2, A_BUCKET_ID)
+            addFolderRow(rowId = 3, A_SECOND_BUCKET_ID)
+        })
+
+        val result = useCase.fetchFolders()
+
+        result shouldBeEqualTo listOf(
+            Folder(
+                bucketId = A_BUCKET_ID,
+                title = A_DISPLAY_NAME,
+                thumbnail = fakeUriAppender.get(rowId = 1),
+            ),
+            Folder(
+                bucketId = A_SECOND_BUCKET_ID,
+                title = A_DISPLAY_NAME,
+                thumbnail = fakeUriAppender.get(rowId = 3),
+            ),
+        )
+        result[0].itemCount shouldBeEqualTo 2
+        result[1].itemCount shouldBeEqualTo 1
+    }
+
+    private fun CreateCursorScope.addFolderRow(rowId: Long, bucketId: String) {
+        addRow(
+            MediaStore.Images.Media._ID to rowId,
+            MediaStore.Images.Media.BUCKET_ID to bucketId,
+            MediaStore.Images.Media.BUCKET_DISPLAY_NAME to A_DISPLAY_NAME,
+            MediaStore.Images.Media.DATE_MODIFIED to A_DATE_MODIFIED,
+        )
+    }
+}
+
+private fun FakeContentResolver.givenFolderQuery() = this.givenQueryResult(
+    A_EXTERNAL_CONTENT_URI.instance,
+    arrayOf(
+        MediaStore.Images.Media._ID,
+        MediaStore.Images.Media.BUCKET_ID,
+        MediaStore.Images.Media.BUCKET_DISPLAY_NAME,
+        MediaStore.Images.Media.DATE_MODIFIED
+    ),
+    "${isNotPending()} AND ${MediaStore.Images.Media.BUCKET_ID} AND ${MediaStore.Images.Media.MIME_TYPE} NOT LIKE ?",
+    arrayOf("%image/svg%"),
+    "${MediaStore.Images.Media.BUCKET_DISPLAY_NAME} COLLATE NOCASE ASC, ${MediaStore.Images.Media.DATE_MODIFIED} DESC",
+)
+
+class FakeUriAppender : (Uri, Long) -> Uri {
+
+    private val uris = mutableMapOf<Long, FakeUri>()
+
+    override fun invoke(uri: Uri, rowId: Long): Uri {
+        val fakeUri = FakeUri()
+        uris[rowId] = fakeUri
+        return fakeUri.instance
+    }
+
+    fun get(rowId: Long) = uris[rowId]!!.instance
+}

features/messenger/src/test/kotlin/app/dapk/st/messenger/gallery/FetchMediaUseCaseTest.kt

@@ -0,0 +1,107 @@
+package app.dapk.st.messenger.gallery
+
+import android.provider.MediaStore
+import fake.FakeContentResolver
+import fake.FakeUri
+import fake.createCursor
+import fixture.CoroutineDispatchersFixture.aCoroutineDispatchers
+import kotlinx.coroutines.test.runTest
+import org.amshove.kluent.shouldBeEqualTo
+import org.junit.Test
+
+private val A_EXTERNAL_CONTENT_URI = FakeUri()
+private val ROW_URI = FakeUri()
+private const val A_BUCKET_ID = "a-bucket-id"
+private const val A_ROW_ID = 20L
+private const val A_MIME_TYPE = "image/png"
+private const val A_DATE_MODIFIED = 5000L
+private const val A_SIZE = 1000L
+private const val A_NORMAL_ORIENTATION = 0
+private const val AN_INVERTED_ORIENTATION = 90
+private const val A_WIDTH = 250
+private const val A_HEIGHT = 750
+
+class FetchMediaUseCaseTest {
+
+    private val fakeContentResolver = FakeContentResolver()
+    private val uriAvoidance = MediaUriAvoidance(
+        uriAppender = { _, _ -> ROW_URI.instance },
+        externalContentUri = A_EXTERNAL_CONTENT_URI.instance,
+    )
+
+    private val useCase = FetchMediaUseCase(fakeContentResolver.instance, uriAvoidance, aCoroutineDispatchers())
+
+    @Test
+    fun `given cursor content, when get media for bucket, then reads media`() = runTest {
+        fakeContentResolver.givenMediaQuery().returns(createCursor {
+            addRow(
+                MediaStore.Images.Media._ID to A_ROW_ID,
+                MediaStore.Images.Media.MIME_TYPE to A_MIME_TYPE,
+                MediaStore.Images.Media.DATE_MODIFIED to A_DATE_MODIFIED,
+                MediaStore.Images.Media.ORIENTATION to A_NORMAL_ORIENTATION,
+                MediaStore.Images.Media.WIDTH to A_WIDTH,
+                MediaStore.Images.Media.HEIGHT to A_HEIGHT,
+                MediaStore.Images.Media.SIZE to A_SIZE,
+            )
+        })
+
+        val result = useCase.getMediaInBucket(A_BUCKET_ID)
+
+        result shouldBeEqualTo listOf(
+            Media(
+                id = A_ROW_ID,
+                uri = ROW_URI.instance,
+                mimeType = A_MIME_TYPE,
+                width = A_WIDTH,
+                height = A_HEIGHT,
+                size = A_SIZE,
+                dateModifiedEpochMillis = A_DATE_MODIFIED
+            )
+        )
+    }
+
+    @Test
+    fun `given cursor content with 90 degree orientation, when get media for bucket, then reads media with inverted width and height`() = runTest {
+        fakeContentResolver.givenMediaQuery().returns(createCursor {
+            addRow(
+                MediaStore.Images.Media._ID to A_ROW_ID,
+                MediaStore.Images.Media.MIME_TYPE to A_MIME_TYPE,
+                MediaStore.Images.Media.DATE_MODIFIED to A_DATE_MODIFIED,
+                MediaStore.Images.Media.ORIENTATION to AN_INVERTED_ORIENTATION,
+                MediaStore.Images.Media.WIDTH to A_WIDTH,
+                MediaStore.Images.Media.HEIGHT to A_HEIGHT,
+                MediaStore.Images.Media.SIZE to A_SIZE,
+            )
+        })
+
+        val result = useCase.getMediaInBucket(A_BUCKET_ID)
+
+        result shouldBeEqualTo listOf(
+            Media(
+                id = A_ROW_ID,
+                uri = ROW_URI.instance,
+                mimeType = A_MIME_TYPE,
+                width = A_HEIGHT,
+                height = A_WIDTH,
+                size = A_SIZE,
+                dateModifiedEpochMillis = A_DATE_MODIFIED
+            )
+        )
+    }
+}
+
+private fun FakeContentResolver.givenMediaQuery() = this.givenQueryResult(
+    A_EXTERNAL_CONTENT_URI.instance,
+    arrayOf(
+        MediaStore.Images.Media._ID,
+        MediaStore.Images.Media.MIME_TYPE,
+        MediaStore.Images.Media.DATE_MODIFIED,
+        MediaStore.Images.Media.ORIENTATION,
+        MediaStore.Images.Media.WIDTH,
+        MediaStore.Images.Media.HEIGHT,
+        MediaStore.Images.Media.SIZE
+    ),
+    MediaStore.Images.Media.BUCKET_ID + " = ? AND " + isNotPending() + " AND " + MediaStore.Images.Media.MIME_TYPE + " NOT LIKE ?",
+    arrayOf(A_BUCKET_ID, "%image/svg%"),
+    MediaStore.Images.Media.DATE_MODIFIED + " DESC",
+)

features/messenger/src/test/kotlin/app/dapk/st/messenger/gallery/state/ImageGalleryReducerTest.kt

@@ -1,54 +1,131 @@
 package app.dapk.st.messenger.gallery.state
 
+import android.net.Uri
 import app.dapk.st.core.Lce
+import app.dapk.st.core.page.PageAction
+import app.dapk.st.core.page.PageContainer
+import app.dapk.st.core.page.PageStateChange
 import app.dapk.st.design.components.SpiderPage
 import app.dapk.st.messenger.gallery.FetchMediaFoldersUseCase
 import app.dapk.st.messenger.gallery.FetchMediaUseCase
-import app.dapk.st.core.page.PageContainer
+import app.dapk.st.messenger.gallery.Folder
+import app.dapk.st.messenger.gallery.Media
 import app.dapk.state.Combined2
 import fake.FakeJobBag
+import fake.FakeUri
+import io.mockk.coEvery
 import io.mockk.mockk
 import org.junit.Test
+import test.assertOnlyDispatches
+import test.delegateReturn
+import test.expect
 import test.testReducer
 
 private const val A_ROOM_NAME = "a room name"
+private val A_FOLDER = Folder(
+    bucketId = "a-bucket-id",
+    title = "a title",
+    thumbnail = FakeUri().instance,
+)
+private val A_MEDIA_RESULT = listOf(aMedia())
+private val A_FOLDERS_RESULT = listOf(aFolder())
+private val AN_INITIAL_FILES_PAGE = SpiderPage(
+    route = ImageGalleryPage.Routes.files,
+    label = "Send to $A_ROOM_NAME",
+    parent = ImageGalleryPage.Routes.folders,
+    state = ImageGalleryPage.Files(Lce.Loading(), A_FOLDER)
+)
+
+private val AN_INITIAL_FOLDERS_PAGE = SpiderPage(
+    route = ImageGalleryPage.Routes.folders,
+    label = "Send to $A_ROOM_NAME",
+    parent = null,
+    state = ImageGalleryPage.Folders(Lce.Loading())
+)
 
 class ImageGalleryReducerTest {
 
     private val fakeJobBag = FakeJobBag()
+    private val fakeFetchMediaFoldersUseCase = FakeFetchMediaFoldersUseCase()
+    private val fakeFetchMediaUseCase = FakeFetchMediaUseCase()
 
     private val runReducerTest = testReducer { _: (Unit) -> Unit ->
         imageGalleryReducer(
             A_ROOM_NAME,
-            FakeFetchMediaFoldersUseCase().instance,
+            fakeFetchMediaFoldersUseCase.instance,
-            FakeFetchMediaUseCase().instance,
+            fakeFetchMediaUseCase.instance,
             fakeJobBag.instance,
         )
     }
 
     @Test
     fun `initial state is folders page`() = runReducerTest {
-        assertInitialState(
+        assertInitialState(pageState(AN_INITIAL_FOLDERS_PAGE))
-            Combined2(
+    }
-                state1 = PageContainer(
+
-                    SpiderPage(
+    @Test
-                        route = ImageGalleryPage.Routes.folders,
+    fun `when Visible, then updates Folders content`() = runReducerTest {
-                        label = "Send to $A_ROOM_NAME",
+        fakeJobBag.instance.expect { it.replace(ImageGalleryPage.Folders::class, any()) }
-                        parent = null,
+        fakeFetchMediaFoldersUseCase.givenFolders().returns(A_FOLDERS_RESULT)
-                        state = ImageGalleryPage.Folders(Lce.Loading())
+
-                    )
+        reduce(ImageGalleryActions.Visible)
-                ),
+
-                state2 = Unit
+        assertOnlyDispatches(
-            )
+            PageStateChange.UpdatePage(AN_INITIAL_FOLDERS_PAGE.state.copy(content = Lce.Content(A_FOLDERS_RESULT)))
         )
     }
 
+    @Test
+    fun `when SelectFolder, then goes to Folder page and fetches content`() = runReducerTest {
+        fakeJobBag.instance.expect { it.replace(ImageGalleryPage.Files::class, any()) }
+        fakeFetchMediaUseCase.givenMedia(A_FOLDER.bucketId).returns(A_MEDIA_RESULT)
+        val goToFolderPage = PageAction.GoTo(AN_INITIAL_FILES_PAGE)
+        actionSideEffect(goToFolderPage) { pageState(goToFolderPage.page) }
+
+        reduce(ImageGalleryActions.SelectFolder(A_FOLDER))
+
+        assertOnlyDispatches(
+            goToFolderPage,
+            PageStateChange.UpdatePage(goToFolderPage.page.state.copy(content = Lce.Content(A_MEDIA_RESULT)))
+        )
+    }
+
+    @Test
+    fun `when ChangePage, then cancels previous page jobs`() = runReducerTest {
+        fakeJobBag.instance.expect { it.cancel(ImageGalleryPage.Folders::class) }
+
+        reduce(PageStateChange.ChangePage(previous = AN_INITIAL_FOLDERS_PAGE, newPage = AN_INITIAL_FILES_PAGE))
+
+        assertOnlyStateChange(pageState(AN_INITIAL_FILES_PAGE))
+    }
 }
 
+private fun <P> pageState(page: SpiderPage<out P>) = Combined2(PageContainer(page), Unit)
+
 class FakeFetchMediaFoldersUseCase {
     val instance = mockk<FetchMediaFoldersUseCase>()
+
+    fun givenFolders() = coEvery { instance.fetchFolders() }.delegateReturn()
 }
 
 class FakeFetchMediaUseCase {
     val instance = mockk<FetchMediaUseCase>()
-}
+
+    fun givenMedia(bucketId: String) = coEvery { instance.getMediaInBucket(bucketId) }.delegateReturn()
+}
+
+fun aMedia(
+    id: Long = 1L,
+    uri: Uri = FakeUri().instance,
+    mimeType: String = "image/png",
+    width: Int = 100,
+    height: Int = 250,
+    size: Long = 1000L,
+    dateModifiedEpochMillis: Long = 5000L,
+) = Media(id, uri, mimeType, width, height, size, dateModifiedEpochMillis)
+
+fun aFolder(
+    bucketId: String = "a-bucket-id",
+    title: String = "a title",
+    thumbnail: Uri = FakeUri().instance,
+) = Folder(bucketId, title, thumbnail)