Retrying firestore array transform tests

Author: ashwinraghav

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/ArrayTransformsTest.java

@@ -27,6 +27,7 @@
 import java.util.Map;
 import org.junit.After;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -37,6 +38,9 @@
  */
 @RunWith(AndroidJUnit4.class)
 public class ArrayTransformsTest {
+  // TODO(b/114769487): These tests have been flaky in CI so temporarily retrying.
+  @Rule public RetryRule retryRule = new RetryRule(3);
+
   // A document reference to read and write to.
   private DocumentReference docRef;
 

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/POJOTest.java

@@ -29,7 +29,6 @@
 
 @RunWith(AndroidJUnit4.class)
 public class POJOTest {
-
   public static class POJO {
 
     double number;

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/RetryRule.java

@@ -0,0 +1,48 @@
+// 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.firestore;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+public class RetryRule implements TestRule {
+  private int retryCount;
+
+  public RetryRule(int retryCount) {
+    this.retryCount = retryCount;
+  }
+
+  public Statement apply(final Statement base, Description description) {
+    return new Statement() {
+      @Override
+      public void evaluate() throws Throwable {
+        Throwable caughtThrowable = null;
+
+        for (int i = 0; i < retryCount; i++) {
+          System.out.println("Trying...." + i);
+          try {
+            base.evaluate();
+            return;
+          } catch (Throwable t) {
+            caughtThrowable = t;
+          }
+        }
+
+        throw caughtThrowable;
+      }
+    };
+  }
+}