Android Instrumentations tests are ready to be run in github/CI open source environment

Reviewed By: mkonicek

Differential Revision: D2769217

fb-gh-sync-id: 7469af816241d8b642753cca21f6542b971e9572

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

@@ -0,0 +1,57 @@
+/**
+ * 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 javax.annotation.Nullable;
+
+import com.facebook.react.bridge.BaseJavaModule;
+import com.facebook.react.bridge.ReactMethod;
+
+import static junit.framework.Assert.assertFalse;
+import static junit.framework.Assert.assertTrue;
+
+/**
+ * NativeModule for tests that allows assertions from JS to propagate to Java.
+ */
+public class AssertModule extends BaseJavaModule {
+
+  private boolean mGotSuccess;
+  private boolean mGotFailure;
+  private @Nullable String mFirstFailureStackTrace;
+
+  @Override
+  public String getName() {
+    return "Assert";
+  }
+
+  @ReactMethod
+  public void fail(String stackTrace) {
+    if (!mGotFailure) {
+      mGotFailure = true;
+      mFirstFailureStackTrace = stackTrace;
+    }
+  }
+
+  @ReactMethod
+  public void success() {
+    mGotSuccess = true;
+  }
+
+  /**
+   * Allows the user of this module to verify that asserts are actually being called from JS and
+   * that none of them failed.
+   */
+  public void verifyAssertsAndReset() {
+    assertFalse("First failure: " + mFirstFailureStackTrace, mGotFailure);
+    assertTrue("Received no assertions during the test!", mGotSuccess);
+    mGotFailure = false;
+    mGotSuccess = false;
+    mFirstFailureStackTrace = null;
+  }
+}