more tests around the directory reducer and helpers

domains/android/compose-core/src/main/kotlin/app/dapk/st/core/ActivityExtensions.kt

@@ -27,6 +27,7 @@ inline fun <reified S, E> ComponentActivity.state(
     noinline factory: () -> StateViewModel<S, E>
 ): Lazy<State<S, E>> {
     val factoryPromise = object : Factory {
+        @Suppress("UNCHECKED_CAST")
         override fun <T : ViewModel> create(modelClass: Class<T>): T {
             return when(modelClass) {
                 StateViewModel::class.java -> factory() as T
@@ -34,7 +35,7 @@ inline fun <reified S, E> ComponentActivity.state(
             }
         }
     }
-    return FooViewModelLazy(
+    return KeyedViewModelLazy(
         key = S::class.java.canonicalName!!,
         StateViewModel::class,
         { viewModelStore },
@@ -42,12 +43,11 @@ inline fun <reified S, E> ComponentActivity.state(
     ) as Lazy<State<S, E>>
 }
 
-class FooViewModelLazy<VM : ViewModel> @JvmOverloads constructor(
+class KeyedViewModelLazy<VM : ViewModel> @JvmOverloads constructor(
     private val key: String,
     private val viewModelClass: KClass<VM>,
     private val storeProducer: () -> ViewModelStore,
     private val factoryProducer: () -> ViewModelProvider.Factory,
-    private val extrasProducer: () -> CreationExtras = { CreationExtras.Empty }
 ) : Lazy<VM> {
     private var cached: VM? = null
 
@@ -60,7 +60,7 @@ class FooViewModelLazy<VM : ViewModel> @JvmOverloads constructor(
                 ViewModelProvider(
                     store,
                     factory,
-                    extrasProducer()
+                    CreationExtras.Empty
                 ).get(key, viewModelClass.java).also {
                     cached = it
                 }

features/directory/src/test/kotlin/app/dapk/st/directory/DirectoryReducerTest.kt

@@ -3,6 +3,7 @@ package app.dapk.st.directory
 import app.dapk.st.directory.state.*
 import app.dapk.st.engine.DirectoryItem
 import app.dapk.st.engine.UnreadCount
+import app.dapk.state.ReducerFactory
 import fake.FakeChatEngine
 import fixture.aRoomOverview
 import io.mockk.mockk
@@ -18,61 +19,71 @@ class DirectoryReducerTest {
     private val fakeShortcutHandler = FakeShortcutHandler()
     private val fakeChatEngine = FakeChatEngine()
     private val fakeJobBag = FakeJobBag()
-    private val fakeEventSource = FakeEventSource<DirectoryEvent>()
 
-    private val reducer = directoryReducer(
-        fakeChatEngine,
-        fakeShortcutHandler.instance,
-        fakeJobBag.instance,
-        fakeEventSource,
-    )
+    private val runReducerTest = testReducer { fakeEventSource ->
+        directoryReducer(
+            fakeChatEngine,
+            fakeShortcutHandler.instance,
+            fakeJobBag.instance,
+            fakeEventSource,
+        )
+    }
 
     @Test
-    fun `initial state is empty loading`() = runReducerTest(reducer) {
+    fun `initial state is empty loading`() = runReducerTest {
         assertInitialState(DirectoryScreenState.EmptyLoading)
     }
 
     @Test
-    fun `given directory content, when Visible, then updates shortcuts and dispatches room state`() = runReducerTest(reducer) {
+    fun `given directory content, when Visible, then updates shortcuts and dispatches room state`() = runReducerTest {
         fakeShortcutHandler.instance.expectUnit { it.onDirectoryUpdate(listOf(AN_OVERVIEW)) }
         fakeJobBag.instance.expect { it.add("sync", any()) }
         fakeChatEngine.givenDirectory().returns(flowOf(listOf(AN_OVERVIEW_STATE)))
 
         reduce(ComponentLifecycle.OnVisible)
 
-        assertNoStateChange()
-        assertDispatches(listOf(DirectoryStateChange.Content(listOf(AN_OVERVIEW_STATE))))
+        assertOnlyDispatches(listOf(DirectoryStateChange.Content(listOf(AN_OVERVIEW_STATE))))
     }
 
     @Test
-    fun `given no directory content, when Visible, then updates shortcuts and dispatches empty state`() = runReducerTest(reducer) {
+    fun `given no directory content, when Visible, then updates shortcuts and dispatches empty state`() = runReducerTest {
         fakeShortcutHandler.instance.expectUnit { it.onDirectoryUpdate(emptyList()) }
         fakeJobBag.instance.expect { it.add("sync", any()) }
         fakeChatEngine.givenDirectory().returns(flowOf(emptyList()))
 
         reduce(ComponentLifecycle.OnVisible)
 
-        assertNoStateChange()
-        assertDispatches(listOf(DirectoryStateChange.Empty))
+        assertOnlyDispatches(listOf(DirectoryStateChange.Empty))
     }
 
     @Test
-    fun `when Gone, then cancels sync job`() = runReducerTest(reducer) {
+    fun `when Gone, then cancels sync job`() = runReducerTest {
         fakeJobBag.instance.expect { it.cancel("sync") }
 
         reduce(ComponentLifecycle.OnGone)
 
-        assertNoStateChange()
-        assertNoDispatches()
+        assertNoChanges()
     }
 
     @Test
-    fun `given ScrollToTop, then emits Scroll event`() = runReducerTest(reducer) {
+    fun `when ScrollToTop, then emits Scroll event`() = runReducerTest {
         reduce(DirectorySideEffect.ScrollToTop)
 
-        assertNoStateChange()
-        assertNoDispatches()
-        fakeEventSource.assertEvents(listOf(DirectoryEvent.ScrollToTop))
+        assertOnlyEvents(listOf(DirectoryEvent.ScrollToTop))
+    }
+
+    @Test
+    fun `when Content StateChange, then returns Content state`() = runReducerTest {
+        reduce(DirectoryStateChange.Content(listOf(AN_OVERVIEW_STATE)))
+
+        assertOnlyStateChange(DirectoryScreenState.Content(listOf(AN_OVERVIEW_STATE)))
+    }
+
+    @Test
+    fun `when Empty StateChange, then returns Empty state`() = runReducerTest {
+        reduce(DirectoryStateChange.Empty)
+
+        assertOnlyStateChange(DirectoryScreenState.Empty)
     }
 }
 
@@ -83,3 +94,4 @@ internal class FakeShortcutHandler {
 class FakeJobBag {
     val instance = mockk<JobBag>()
 }
+

features/directory/src/test/kotlin/app/dapk/st/directory/FakeEventSource.kt

@@ -4,7 +4,7 @@ import org.amshove.kluent.internal.assertEquals
 
 class FakeEventSource<E> : (E) -> Unit {
 
-    val captures = mutableListOf<E>()
+    private val captures = mutableListOf<E>()
 
     override fun invoke(event: E) {
         captures.add(event)
@@ -13,4 +13,8 @@ class FakeEventSource<E> : (E) -> Unit {
     fun assertEvents(expected: List<E>) {
         assertEquals(expected, captures)
     }
+
+    fun assertNoEvents() {
+        assertEquals(emptyList(), captures)
+    }
 }

features/directory/src/test/kotlin/app/dapk/st/directory/ReducerTest.kt

@@ -12,16 +12,31 @@ import org.amshove.kluent.shouldBeEqualTo
 import test.ExpectTest
 import test.ExpectTestScope
 
-fun <S> runReducerTest(reducerFactory: ReducerFactory<S>, block: suspend ReducerTestScope<S>.() -> Unit) {
+interface ReducerTest<S, E> {
+    operator fun invoke(block: suspend ReducerTestScope<S, E>.() -> Unit)
+}
+
+fun <S, E> testReducer(block: ((E) -> Unit) -> ReducerFactory<S>): ReducerTest<S, E> {
+    val fakeEventSource = FakeEventSource<E>()
+    val reducerFactory = block(fakeEventSource)
+    return object : ReducerTest<S, E> {
+        override fun invoke(block: suspend ReducerTestScope<S, E>.() -> Unit) {
+            runReducerTest(reducerFactory, fakeEventSource, block)
+        }
+    }
+}
+
+fun <S, E> runReducerTest(reducerFactory: ReducerFactory<S>, fakeEventSource: FakeEventSource<E>, block: suspend ReducerTestScope<S, E>.() -> Unit) {
     runTest {
         val expectTestScope = ExpectTest(coroutineContext)
-        block(ReducerTestScope(reducerFactory, expectTestScope))
+        block(ReducerTestScope(reducerFactory, fakeEventSource, expectTestScope))
         expectTestScope.verifyExpects()
     }
 }
 
-class ReducerTestScope<S>(
+class ReducerTestScope<S, E>(
     private val reducerFactory: ReducerFactory<S>,
+    private val fakeEventSource: FakeEventSource<E>,
     private val expectTestScope: ExpectTestScope
 ) : ExpectTestScope by expectTestScope, Reducer<S> {
 
@@ -51,7 +66,17 @@ class ReducerTestScope<S>(
         reducerFactory.initialState() shouldBeEqualTo expected
     }
 
-    fun <S> assertDispatches(expected: List<S>) {
+    fun assertOnlyStateChange(expected: S) {
+        assertStateChange(expected)
+        assertNoDispatches()
+        fakeEventSource.assertNoEvents()
+    }
+
+    fun assertStateChange(expected: S) {
+        capturedResult shouldBeEqualTo expected
+    }
+
+    fun assertDispatches(expected: List<Action>) {
         assertEquals(expected, actionCaptures)
     }
 
@@ -62,4 +87,22 @@ class ReducerTestScope<S>(
     fun assertNoStateChange() {
         assertEquals(reducerFactory.initialState(), capturedResult)
     }
+
+    fun assertOnlyDispatches(expected: List<Action>) {
+        assertDispatches(expected)
+        fakeEventSource.assertNoEvents()
+        assertNoStateChange()
+    }
+
+    fun assertOnlyEvents(events: List<E>) {
+        fakeEventSource.assertEvents(events)
+        assertNoDispatches()
+        assertNoStateChange()
+    }
+
+    fun assertNoChanges() {
+        assertNoStateChange()
+        fakeEventSource.assertNoEvents()
+        assertNoDispatches()
+    }
 }