[ReactNative] Add integration test stuff

IntegrationTests/IntegrationTestHarnessTest.js

@@ -0,0 +1,57 @@
+/**
+ * Copyright 2004-present Facebook. All Rights Reserved.
+ */
+'use strict';
+
+var RCTTestModule = require('NativeModules').RCTTestModule;
+var React = require('react-native');
+var {
+  Text,
+  View,
+} = React;
+
+var IntegrationTestHarnessTest = React.createClass({
+  propTypes: {
+    shouldThrow: React.PropTypes.bool,
+    waitOneFrame: React.PropTypes.bool,
+  },
+
+  getInitialState() {
+    return {
+      done: false,
+    };
+  },
+
+  componentDidMount() {
+    if (this.props.waitOneFrame) {
+      requestAnimationFrame(this.runTest);
+    } else {
+      this.runTest();
+    }
+  },
+
+  runTest() {
+    if (this.props.shouldThrow) {
+      throw new Error('Throwing error because shouldThrow');
+    }
+    if (!RCTTestModule) {
+      throw new Error('RCTTestModule is not registered.');
+    } else if (!RCTTestModule.markTestCompleted) {
+      throw new Error('RCTTestModule.markTestCompleted not defined.');
+    }
+    this.setState({done: true}, RCTTestModule.markTestCompleted);
+  },
+
+  render() {
+    return (
+      <View style={{backgroundColor: 'white', padding: 40}}>
+        <Text>
+          {this.constructor.displayName + ': '}
+          {this.state.done ? 'Done' : 'Testing...'}
+        </Text>
+      </View>
+    );
+  }
+});
+
+module.exports = IntegrationTestHarnessTest;