Sets up AutoSavePostIfNotDraftUseCaseTest and adds fetch post status …

…error test

WordPress/src/test/java/org/wordpress/android/ui/posts/AutoSavePostIfNotDraftUseCaseTest.kt

@@ -0,0 +1,101 @@
+package org.wordpress.android.ui.posts
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import com.nhaarman.mockitokotlin2.any
+import com.nhaarman.mockitokotlin2.whenever
+import kotlinx.coroutines.InternalCoroutinesApi
+import org.junit.Rule
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.junit.MockitoJUnitRunner
+import org.wordpress.android.fluxc.Dispatcher
+import org.wordpress.android.fluxc.model.PostModel
+import org.wordpress.android.fluxc.model.SiteModel
+import org.wordpress.android.fluxc.store.PostStore
+import org.wordpress.android.fluxc.store.PostStore.OnPostStatusFetched
+import org.wordpress.android.fluxc.store.PostStore.PostError
+import org.wordpress.android.fluxc.store.PostStore.PostErrorType.UNKNOWN_POST
+import org.wordpress.android.fluxc.store.PostStore.RemotePostPayload
+import org.wordpress.android.ui.uploads.AutoSavePostIfNotDraftResult
+import org.wordpress.android.ui.uploads.AutoSavePostIfNotDraftUseCase
+import org.wordpress.android.ui.uploads.OnAutoSavePostIfNotDraftCallback
+import java.lang.reflect.Constructor
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+import org.wordpress.android.TEST_DISPATCHER
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+
+private const val FETCH_POST_STATUS_ERROR_MESSAGE = "FETCH_POST_STATUS_ERROR_MESSAGE"
+private const val DRAFT_STATUS = "DRAFT"
+
+@InternalCoroutinesApi
+@RunWith(MockitoJUnitRunner::class)
+class AutoSavePostIfNotDraftUseCaseTest {
+    @Rule
+    @JvmField val rule = InstantTaskExecutorRule()
+
+    @Mock lateinit var dispatcher: Dispatcher
+    @Mock lateinit var postStore: PostStore
+
+    @Test
+    fun `error while fetching post status will result in FetchPostStatusFailed`() {
+        val useCase = createUseCase()
+        val error = PostError(UNKNOWN_POST, FETCH_POST_STATUS_ERROR_MESSAGE)
+        val remotePostPayload = createRemotePostPayload()
+        whenever(dispatcher.dispatch(any())).then {
+            useCase.onPostStatusFetched(
+                    createOnPostStatusFetchedEvent(
+                            post = remotePostPayload.post,
+                            status = DRAFT_STATUS,
+                            error = error
+                    )
+            )
+        }
+        useCase.autoSavePostOrUpdateDraftAndAssertResult(remotePostPayload) { result ->
+            assertThat(result).isInstanceOf(AutoSavePostIfNotDraftResult.FetchPostStatusFailed::class.java)
+        }
+    }
+
+    private fun createUseCase() = AutoSavePostIfNotDraftUseCase(
+            dispatcher = dispatcher,
+            postStore = postStore,
+            bgDispatcher = TEST_DISPATCHER
+    )
+
+    private fun createRemotePostPayload() = RemotePostPayload(PostModel(), SiteModel())
+
+    /**
+     * Since the `OnPostStatusFetched` is package-private we utilize reflection for the test. Without being able to
+     * create `OnPostStatusFetched` event, we can't write most of the unit tests for `AutoSavePostIfNotDraftUseCase`.
+     */
+    private fun createOnPostStatusFetchedEvent(
+        post: PostModel,
+        status: String,
+        error: PostError? = null
+    ): OnPostStatusFetched {
+        val constructor: Constructor<OnPostStatusFetched> = OnPostStatusFetched::class.java.getDeclaredConstructor(
+                PostModel::class.java,
+                String::class.java,
+                PostError::class.java
+        )
+        constructor.isAccessible = true
+        return constructor.newInstance(post, status, error)
+    }
+}
+
+private fun AutoSavePostIfNotDraftUseCase.autoSavePostOrUpdateDraftAndAssertResult(
+    remotePostPayload: RemotePostPayload,
+    assertionBlock: (AutoSavePostIfNotDraftResult) -> Unit
+) {
+    val countDownLatch = CountDownLatch(1)
+    autoSavePostOrUpdateDraft(
+            remotePostPayload,
+            object : OnAutoSavePostIfNotDraftCallback {
+                override fun handleAutoSavePostIfNotDraftResult(result: AutoSavePostIfNotDraftResult) {
+                    assertionBlock(result)
+                    countDownLatch.countDown()
+                }
+            })
+    assertThat(countDownLatch.await(1, TimeUnit.SECONDS)).isTrue()
+}