Add tests for skip positions

modules/features/endofyear/src/test/java/au/com/shiftyjelly/pocketcasts/endofyear/StoriesViewModelTest.kt

@@ -1,6 +1,7 @@
 package au.com.shiftyjelly.pocketcasts.endofyear
 
 import au.com.shiftyjelly.pocketcasts.endofyear.stories.Story
+import au.com.shiftyjelly.pocketcasts.utils.seconds
 import junit.framework.TestCase.assertEquals
 import junit.framework.TestCase.assertTrue
 import kotlinx.coroutines.Dispatchers
@@ -18,6 +19,8 @@ import org.junit.runner.RunWith
 import org.mockito.junit.MockitoJUnitRunner
 import org.mockito.kotlin.mock
 import org.mockito.kotlin.verify
+import org.mockito.kotlin.whenever
+import kotlin.math.roundToInt
 
 private val story1 = mock<Story>()
 private val story2 = mock<Story>()
@@ -109,6 +112,48 @@ class StoriesViewModelTest {
         assertEquals(state.currentStory, story1)
     }
 
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun `when next is invoked, then story skips to correct position`() = runTest {
+        whenever(story1.storyLength).thenReturn(5.seconds())
+        whenever(story2.storyLength).thenReturn(10.seconds())
+        val viewModel = StoriesViewModel(MockStoriesDataSource(listOf(story1, story2)))
+        val progress = mutableListOf<Float>()
+        val collectJob = launch(UnconfinedTestDispatcher()) {
+            viewModel.progress.collect {
+                progress.add(it)
+            }
+        }
+
+        viewModel.skipNext()
+
+        assertEquals(0.34f, (progress.last() * 100f).roundToInt() / 100f)
+        collectJob.cancel()
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun `when prev is invoked, then story skips to correct position`() = runTest {
+        val story3 = mock<Story>()
+        whenever(story1.storyLength).thenReturn(5.seconds())
+        whenever(story2.storyLength).thenReturn(10.seconds())
+        whenever(story3.storyLength).thenReturn(5.seconds())
+        val viewModel = StoriesViewModel(MockStoriesDataSource(listOf(story1, story2, story3)))
+        viewModel.skipNext()
+        viewModel.skipNext() // At last story
+        val progress = mutableListOf<Float>()
+        val collectJob = launch(UnconfinedTestDispatcher()) {
+            viewModel.progress.collect {
+                progress.add(it)
+            }
+        }
+
+        viewModel.skipPrevious() // Skip to middle story
+
+        assertEquals(0.25f, (progress.last() * 100f).roundToInt() / 100f)
+        collectJob.cancel()
+    }
+
     class MockStoriesDataSource(private val mockStories: List<Story>) : StoriesDataSource() {
         override val stories = mutableListOf<Story>()