Add unit tests for GetTimelineEventUseCase

vector/src/main/java/im/vector/app/core/event/GetTimelineEventUseCase.kt

@@ -20,6 +20,7 @@ import androidx.lifecycle.asFlow
 import im.vector.app.core.di.ActiveSessionHolder
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.emptyFlow
+import org.matrix.android.sdk.api.session.getRoom
 import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
 import org.matrix.android.sdk.flow.unwrap
 import javax.inject.Inject
@@ -30,7 +31,7 @@ class GetTimelineEventUseCase @Inject constructor(
 ) {
 
     fun execute(roomId: String, eventId: String): Flow<TimelineEvent> {
-        return activeSessionHolder.getActiveSession().roomService().getRoom(roomId)
+        return activeSessionHolder.getActiveSession().getRoom(roomId)
                 ?.timelineService()
                 ?.getTimelineEventLive(eventId)
                 ?.asFlow()

vector/src/test/java/im/vector/app/core/event/GetTimelineEventUseCaseTest.kt

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * 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
+ *
+ *     http://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 im.vector.app.core.event
+
+import im.vector.app.test.fakes.FakeActiveSessionHolder
+import im.vector.app.test.fakes.FakeFlowLiveDataConversions
+import im.vector.app.test.fakes.givenAsFlow
+import im.vector.app.test.test
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.unmockkAll
+import kotlinx.coroutines.flow.firstOrNull
+import kotlinx.coroutines.test.runCurrent
+import kotlinx.coroutines.test.runTest
+import org.amshove.kluent.shouldBeNull
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
+
+private const val A_ROOM_ID = "room-id"
+private const val AN_EVENT_ID = "event-id"
+
+internal class GetTimelineEventUseCaseTest {
+
+    private val fakeFlowLiveDataConversions = FakeFlowLiveDataConversions()
+    private val fakeActiveSessionHolder = FakeActiveSessionHolder()
+    private val getTimelineEventUseCase = GetTimelineEventUseCase(fakeActiveSessionHolder.instance)
+
+    @Before
+    fun setUp() {
+        fakeFlowLiveDataConversions.setup()
+    }
+
+    @After
+    fun tearDown() {
+        unmockkAll()
+    }
+
+    @Test
+    fun `given a non existing room id, when execute, then returns an empty flow`() = runTest {
+        // Given
+        every { fakeActiveSessionHolder.instance.getActiveSession().roomService().getRoom(A_ROOM_ID) } returns null
+
+        // When
+        val result = getTimelineEventUseCase.execute(A_ROOM_ID, AN_EVENT_ID).firstOrNull()
+
+        // Then
+        result.shouldBeNull()
+    }
+
+    @Test
+    fun `given a LiveData of TimelineEvent, when execute, then returns the expected Flow`() = runTest {
+        // Given
+        val aTimelineEvent1: TimelineEvent = mockk()
+        val aTimelineEvent2: TimelineEvent? = null
+        val timelineService = fakeActiveSessionHolder.fakeSession
+                .fakeRoomService
+                .getRoom(A_ROOM_ID)
+                .timelineService()
+
+        // When
+        timelineService.givenTimelineEventLiveReturns(AN_EVENT_ID, aTimelineEvent1).givenAsFlow()
+        val result1 = getTimelineEventUseCase.execute(A_ROOM_ID, AN_EVENT_ID).test(this)
+
+        timelineService.givenTimelineEventLiveReturns(AN_EVENT_ID, aTimelineEvent2).givenAsFlow()
+        val result2 = getTimelineEventUseCase.execute(A_ROOM_ID, AN_EVENT_ID).test(this)
+
+        // Then
+        runCurrent()
+        result1.assertLatestValue(aTimelineEvent1)
+        result2.assertNoValues()
+    }
+}

vector/src/test/java/im/vector/app/test/fakes/FakeTimelineService.kt

@@ -16,14 +16,26 @@
 
 package im.vector.app.test.fakes
 
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
 import io.mockk.every
 import io.mockk.mockk
 import org.matrix.android.sdk.api.session.room.timeline.TimelineEvent
 import org.matrix.android.sdk.api.session.room.timeline.TimelineService
+import org.matrix.android.sdk.api.util.Optional
 
 class FakeTimelineService : TimelineService by mockk() {
 
     fun givenTimelineEventReturns(eventId: String, event: TimelineEvent?) {
         every { getTimelineEvent(eventId) } returns event
     }
+
+    fun givenTimelineEventLiveReturns(
+            eventId: String,
+            event: TimelineEvent?
+    ): LiveData<Optional<TimelineEvent>> {
+        return MutableLiveData(Optional(event)).also {
+            every { getTimelineEventLive(eventId) } returns it
+        }
+    }
 }