Adding unit tests for ViewModel

vector/src/main/java/im/vector/app/features/roomprofile/polls/RoomPollsViewModel.kt

@@ -16,6 +16,7 @@
 
 package im.vector.app.features.roomprofile.polls
 
+import androidx.annotation.VisibleForTesting
 import com.airbnb.mvrx.MavericksViewModelFactory
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedFactory
@@ -39,9 +40,9 @@ class RoomPollsViewModel @AssistedInject constructor(
 
     companion object : MavericksViewModelFactory<RoomPollsViewModel, RoomPollsViewState> by hiltMavericksViewModelFactory()
 
-    private var pollsCollectionJob: Job? = null
+    @VisibleForTesting
+    var pollsCollectionJob: Job? = null
 
-    // TODO add unit tests
     override fun handle(action: RoomPollsAction) {
         when (action) {
             is RoomPollsAction.SetFilter -> handleSetFilter(action.filter)

vector/src/test/java/im/vector/app/features/roomprofile/polls/RoomPollsViewModelTest.kt

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2022 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.features.roomprofile.polls
+
+import com.airbnb.mvrx.test.MavericksTestRule
+import im.vector.app.test.test
+import im.vector.app.test.testDispatcher
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import kotlinx.coroutines.flow.flowOf
+import org.amshove.kluent.shouldNotBeNull
+import org.junit.Rule
+import org.junit.Test
+
+private const val ROOM_ID = "room-id"
+
+class RoomPollsViewModelTest {
+
+    @get:Rule
+    val mavericksTestRule = MavericksTestRule(testDispatcher = testDispatcher)
+
+    private val fakeGetPollsUseCase = mockk<GetPollsUseCase>()
+    private val initialState = RoomPollsViewState(ROOM_ID)
+
+    private fun createViewModel(): RoomPollsViewModel {
+        return RoomPollsViewModel(
+                initialState = initialState,
+                getPollsUseCase = fakeGetPollsUseCase,
+        )
+    }
+
+    @Test
+    fun `given SetFilter action when handle then useCase is called with given filter and viewState is updated`() {
+        // Given
+        val filter = RoomPollsFilter.ACTIVE
+        val action = RoomPollsAction.SetFilter(filter = filter)
+        val polls = listOf(givenAPollSummary())
+        every { fakeGetPollsUseCase.execute(any()) } returns flowOf(polls)
+        val viewModel = createViewModel()
+        val expectedViewState = initialState.copy(polls = polls)
+
+        // When
+        val viewModelTest = viewModel.test()
+        viewModel.pollsCollectionJob = null
+        viewModel.handle(action)
+
+        // Then
+        viewModelTest
+                .assertLatestState(expectedViewState)
+                .finish()
+        viewModel.pollsCollectionJob.shouldNotBeNull()
+        verify {
+            viewModel.pollsCollectionJob?.cancel()
+            fakeGetPollsUseCase.execute(filter)
+        }
+    }
+
+    private fun givenAPollSummary(): PollSummary {
+        return mockk()
+    }
+}