TEST: implement unittests for RemindersListViewModel

jploz · jploz · commit 595056651b6e · 2021-05-04T06:27:04.000+02:00
diff --git a/app/src/test/java/com/udacity/locationreminder/locationreminders/reminderslist/RemindersListViewModelTest.kt b/app/src/test/java/com/udacity/locationreminder/locationreminders/reminderslist/RemindersListViewModelTest.kt
@@ -1,13 +1,122 @@
 package com.udacity.locationreminder.locationreminders.reminderslist
 
+import android.app.Application
+import android.content.Context
+import android.os.Build
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.udacity.locationreminder.locationreminders.MainCoroutineRule
+import com.udacity.locationreminder.locationreminders.data.FakeDataSource
+import com.udacity.locationreminder.locationreminders.data.dto.ReminderDTO
+import com.udacity.locationreminder.locationreminders.getOrAwaitValue
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.test.runBlockingTest
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.core.Is.`is`
+import org.junit.After
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
 import org.junit.runner.RunWith
+import org.koin.core.context.stopKoin
+import org.robolectric.annotation.Config
 
 @RunWith(AndroidJUnit4::class)
+@Config(sdk = [Build.VERSION_CODES.P])
 @ExperimentalCoroutinesApi
 class RemindersListViewModelTest {
 
-    //TODO: provide testing to the RemindersListViewModel and its live data objects
+    @get:Rule
+    var mainCoroutineRule = MainCoroutineRule()
 
-}
+    private lateinit var repository: FakeDataSource
+    private lateinit var appContext: Context
+
+    // Subject under test
+    private lateinit var viewModel: RemindersListViewModel
+
+    @get:Rule
+    var instantExecutorRule = InstantTaskExecutorRule()
+
+    @Before
+    fun setupViewModel() {
+        val reminders = mutableListOf(
+            ReminderDTO(
+                title = "Title of reminder 1",
+                description = "Description of reminder 1",
+                location = "User defined location",
+                latitude = 10.0,
+                longitude = 10.0
+            ),
+            ReminderDTO(
+                title = "Title of reminder 2",
+                description = "Description of reminder 2",
+                location = "User defined location",
+                latitude = 20.0,
+                longitude = 20.0
+            ),
+        )
+
+        repository = FakeDataSource(reminders = reminders)
+        appContext = ApplicationProvider.getApplicationContext()
+        viewModel = RemindersListViewModel(appContext as Application, repository)
+    }
+
+    @After
+    fun tearDownViewModel() {
+        // ensure clean data for tests
+        runBlocking {
+            repository.deleteAllReminders()
+        }
+
+        // Koin instance must be stopped between tests
+        stopKoin()
+    }
+
+    @Test
+    fun showNoData_noReminders_isTrue() = runBlockingTest {
+        repository.deleteAllReminders()
+        viewModel.loadReminders()
+        assertThat(viewModel.showNoData.getOrAwaitValue(), `is`(true))
+    }
+
+    @Test
+    fun showNoData_withData_isFalse() = runBlockingTest {
+        viewModel.loadReminders()
+        assertThat(viewModel.showNoData.getOrAwaitValue(), `is`(false))
+    }
+
+    @Test
+    fun showLoading_noData_isTrueWhileLoading() = runBlockingTest {
+        repository.deleteAllReminders()
+        mainCoroutineRule.pauseDispatcher()
+        viewModel.loadReminders()
+        assertThat(viewModel.showLoading.getOrAwaitValue(), `is`(true))
+        mainCoroutineRule.resumeDispatcher()
+        assertThat(viewModel.showLoading.getOrAwaitValue(), `is`(false))
+    }
+
+    @Test
+    fun showLoading_withData_isTrueWhileLoading() = runBlockingTest {
+        mainCoroutineRule.pauseDispatcher()
+        viewModel.loadReminders()
+        assertThat(viewModel.showLoading.getOrAwaitValue(), `is`(true))
+        mainCoroutineRule.resumeDispatcher()
+        assertThat(viewModel.showLoading.getOrAwaitValue(), `is`(false))
+    }
+
+    @Test
+    fun remindersList_noData_isEmpty() = runBlockingTest {
+        repository.deleteAllReminders()
+        viewModel.loadReminders()
+        assertThat(viewModel.remindersList.getOrAwaitValue().isEmpty(), `is`(true))
+    }
+
+    @Test
+    fun remindersList_withData_isNotEmpty() = runBlockingTest {
+        viewModel.loadReminders()
+        assertThat(viewModel.remindersList.getOrAwaitValue().isEmpty(), `is`(false))
+    }
+}
