WebWorkers: Add simple integration test

Summary:
public

Adds a simple integration test that verifies that a message can be posted to/from the worker andthat it's torn down properly.

Reviewed By: lexs

Differential Revision: D2815244

fb-gh-sync-id: 00c0d8933d785b2913d378c0589b2fbabf0d0edb

ReactAndroid/src/androidTest/java/com/facebook/react/testing/IntRecordingModule.java

@@ -0,0 +1,56 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.testing;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import com.facebook.react.bridge.BaseJavaModule;
+import com.facebook.react.bridge.ReactMethod;
+
+/**
+ * Native module provides single method {@link #record} which records its single int argument
+ * in calls array
+ */
+public class IntRecordingModule extends BaseJavaModule {
+
+  private final List<Integer> mCalls = new ArrayList<>();
+  private final CountDownLatch mCountDownLatch = new CountDownLatch(1);
+
+  @Override
+  public String getName() {
+    return "Recording";
+  }
+
+  @ReactMethod
+  public void record(int i) {
+    mCalls.add(i);
+    mCountDownLatch.countDown();
+  }
+
+  public void reset() {
+    mCalls.clear();
+  }
+
+  public List<Integer> getCalls() {
+    return mCalls;
+  }
+
+  public void waitForFirstCall() {
+    try {
+      if (!mCountDownLatch.await(15000, TimeUnit.MILLISECONDS)) {
+        throw new RuntimeException("Timed out waiting for first call");
+      }
+    } catch (InterruptedException e) {
+      throw new RuntimeException(e);
+    }
+  }
+}

ReactAndroid/src/androidTest/java/com/facebook/react/testing/ReactIntegrationTestCase.java

@@ -14,6 +14,7 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 
+import android.app.Application;
 import android.support.test.InstrumentationRegistry;
 import android.test.AndroidTestCase;
 import android.view.View;
@@ -27,6 +28,7 @@ import com.facebook.react.bridge.CatalystInstanceImpl;
 import com.facebook.react.bridge.LifecycleEventListener;
 import com.facebook.react.bridge.SoftAssertions;
 import com.facebook.react.bridge.UiThreadUtil;
+import com.facebook.react.common.ApplicationHolder;
 import com.facebook.react.common.futures.SimpleSettableFuture;
 import com.facebook.react.modules.core.Timing;
 
@@ -155,6 +157,7 @@ public abstract class ReactIntegrationTestCase extends AndroidTestCase {
               mBridgeIdleSignaler = new ReactBridgeIdleSignaler();
               mInstance.addBridgeIdleDebugListener(mBridgeIdleSignaler);
               getContext().initializeWithInstance(mInstance);
+              ApplicationHolder.setApplication((Application) getContext().getApplicationContext());
               setupEvent.occur();
             }
           });