Add TestId for reduced flakiness.

smoke-tests/src/database/java/com/google/firebase/testing/database/DatabaseTest.java

@@ -28,6 +28,7 @@
 import com.google.firebase.database.FirebaseDatabase;
 import com.google.firebase.database.ValueEventListener;
 import com.google.firebase.testing.common.Tasks2;
+import com.google.firebase.testing.common.TestId;
 import java.util.HashMap;
 import org.junit.Rule;
 import org.junit.Test;
@@ -48,20 +49,24 @@ public void setValueShouldTriggerListenerWithNewlySetData() throws Exception {
     Task<?> signInTask = auth.signInWithEmailAndPassword("[email protected]", "password");
     Tasks2.waitForSuccess(signInTask);
 
-    DatabaseReference doc = database.getReference("restaurants").child("Baadal");
+    DatabaseReference doc = database.getReference("restaurants").child(TestId.create());
     SnapshotListener listener = new SnapshotListener();
     doc.addListenerForSingleValueEvent(listener);
 
     HashMap<String, Object> data = new HashMap<>();
     data.put("location", "Google NYC");
 
-    Task<?> setTask = doc.setValue(new HashMap<>(data));
-    Task<DataSnapshot> snapshotTask = listener.toTask();
-    Tasks2.waitForSuccess(setTask);
-    Tasks2.waitForSuccess(snapshotTask);
+    try {
+      Task<?> setTask = doc.setValue(new HashMap<>(data));
+      Task<DataSnapshot> snapshotTask = listener.toTask();
+      Tasks2.waitForSuccess(setTask);
+      Tasks2.waitForSuccess(snapshotTask);
 
-    DataSnapshot result = snapshotTask.getResult();
-    assertThat(result.getValue()).isEqualTo(data);
+      DataSnapshot result = snapshotTask.getResult();
+      assertThat(result.getValue()).isEqualTo(data);
+    } finally {
+      Tasks2.waitBestEffort(doc.removeValue());
+    }
   }
 
   private static class SnapshotListener implements ValueEventListener {

smoke-tests/src/firestore/java/com/google/firebase/testing/firestore/FirestoreTest.java

@@ -29,6 +29,7 @@
 import com.google.firebase.firestore.FirebaseFirestoreException;
 import com.google.firebase.firestore.ListenerRegistration;
 import com.google.firebase.testing.common.Tasks2;
+import com.google.firebase.testing.common.TestId;
 import java.util.HashMap;
 import org.junit.Rule;
 import org.junit.Test;
@@ -41,15 +42,15 @@ public final class FirestoreTest {
   @Rule public final ActivityTestRule<Activity> activity = new ActivityTestRule<>(Activity.class);
 
   @Test
-  public void listenForUpdate() throws Exception {
+  public void setShouldTriggerListenerWithNewlySetData() throws Exception {
     FirebaseAuth auth = FirebaseAuth.getInstance();
     FirebaseFirestore firestore = FirebaseFirestore.getInstance();
 
     auth.signOut();
     Task<?> signInTask = auth.signInWithEmailAndPassword("[email protected]", "password");
     Tasks2.waitForSuccess(signInTask);
 
-    DocumentReference doc = firestore.collection("restaurants").document("Baadal");
+    DocumentReference doc = firestore.collection("restaurants").document(TestId.create());
     SnapshotListener listener = new SnapshotListener();
     ListenerRegistration registration = doc.addSnapshotListener(listener);
 
@@ -66,6 +67,7 @@ public void listenForUpdate() throws Exception {
       assertThat(result.getData()).isEqualTo(data);
     } finally {
       registration.remove();
+      Tasks2.waitBestEffort(doc.delete());
     }
   }
 

smoke-tests/src/main/java/com/google/firebase/testing/common/Tasks2.java

@@ -17,16 +17,39 @@
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.TimeUnit;
 
 /** Test utilities for asynchronous tasks. */
 public final class Tasks2 {
 
+  private static final long BEST_EFFORT_DURATION = 10;
   private static final long WAIT_DURATION = 30;
   private static final TimeUnit WAIT_UNIT = TimeUnit.SECONDS;
 
   private Tasks2() {}
 
+  /**
+   * Waits for the task to complete.
+   *
+   * <p>The primary use case for this method is to perform test clean-up in a {@code finally} block.
+   * Clean-up is inherently a best-effort task, because it might not succeed when the test is
+   * broken.
+   *
+   * <p>This method will block the current thread for a short period of time. Unlike the other
+   * methods in this class, this method is not biased towards success or failure. This method does
+   * not throw any exceptions.
+   */
+  public static void waitBestEffort(Task<?> task) {
+    try {
+      Tasks.await(task, BEST_EFFORT_DURATION, WAIT_UNIT);
+    } catch (InterruptedException ex) {
+      Thread.currentThread().interrupt();
+    } catch (ExecutionException | TimeoutException ex) {
+      // Ignore.
+    }
+  }
+
   /**
    * Waits for the task to complete successfully.
    *

smoke-tests/src/main/java/com/google/firebase/testing/common/TestId.java

@@ -0,0 +1,35 @@
+// Copyright 2018 Google LLC
+//
+// 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 com.google.firebase.testing.common;
+
+import java.util.UUID;
+
+/**
+ * A utility for generating ids for some sort of entity for testing.
+ *
+ * <p>Examples of test ids include paths to database documents and storage files. This class
+ * randomly generates ids so that concurrent test runs do not share state. Ids generated by this
+ * class are guaranteed to begin with a letter, not use special characters, and have no slashes.
+ *
+ * <p>This implementation returns strings 21 characters long. All ids begin with the letter {@code
+ * t} to ensure the first character is a letter. The remaining characters are lower-case hexadecimal
+ * characters.
+ */
+public final class TestId {
+
+  public static String create() {
+    return "t" + UUID.randomUUID().toString().replace("-", "").substring(0, 20).toLowerCase();
+  }
+}

smoke-tests/src/storage/java/com/google/firebase/testing/storage/StorageTest.java

@@ -24,6 +24,7 @@
 import com.google.firebase.storage.FirebaseStorage;
 import com.google.firebase.storage.StorageReference;
 import com.google.firebase.testing.common.Tasks2;
+import com.google.firebase.testing.common.TestId;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import org.junit.Rule;
@@ -45,17 +46,21 @@ public void getShouldReturnNewlyPutData() throws Exception {
     Task<?> signInTask = auth.signInWithEmailAndPassword("[email protected]", "password");
     Tasks2.waitForSuccess(signInTask);
 
-    StorageReference blob = storage.getReference("restaurants/Baadal");
+    StorageReference blob = storage.getReference("restaurants").child(TestId.create());
 
     byte[] data = "Google NYC".getBytes(StandardCharsets.UTF_8);
 
-    Task<?> putTask = blob.putBytes(Arrays.copyOf(data, data.length));
-    Tasks2.waitForSuccess(putTask);
+    try {
+      Task<?> putTask = blob.putBytes(Arrays.copyOf(data, data.length));
+      Tasks2.waitForSuccess(putTask);
 
-    Task<byte[]> getTask = blob.getBytes(128);
-    Tasks2.waitForSuccess(getTask);
+      Task<byte[]> getTask = blob.getBytes(128);
+      Tasks2.waitForSuccess(getTask);
 
-    byte[] result = getTask.getResult();
-    assertThat(result).isEqualTo(data);
+      byte[] result = getTask.getResult();
+      assertThat(result).isEqualTo(data);
+    } finally {
+      Tasks2.waitBestEffort(blob.delete());
+    }
   }
 }