Add some `Fake`s for easier interaction snapshot testing

Summary:
`Fake` components are simplified so snapshots are stable and reliable, and references are exported
so that interactions like `onRefresh` and `onScroll` can be called manually. Currently there is just
one global export for each class, but we may change this in the future if we need to manage multiple
`Fake`s of the same type in one render tree.

Right now these must be installed explicitly, but I might move them into `__mocks__` folders if it
seems reasonable to make them defaults.

Reviewed By: cpojer

Differential Revision: D4318207

fbshipit-source-id: 62802353a98b09ca1c80804ef7201ea63091f94a

Libraries/Components/RefreshControl/RefreshControl.js

@@ -152,7 +152,7 @@ const RefreshControl = React.createClass({
     return (
       <NativeRefreshControl
         {...this.props}
-        ref={ref => this._nativeRef = ref}
+        ref={ref => {this._nativeRef = ref;}}
         onRefresh={this._onRefresh}
       />
     );

Libraries/Components/RefreshControl/__mocks__/RefreshControlMock.js

@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2015-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.
+ *
+ * @flow
+ */
+'use strict';
+
+const React = require('React');
+
+const requireNativeComponent = require('requireNativeComponent');
+
+const RCTRefreshControl = requireNativeComponent('RCTRefreshControl');
+
+class RefreshControlMock extends React.Component {
+  static latestRef: ?RefreshControlMock;
+  componentDidMount() {
+    RefreshControlMock.latestRef = this;
+  }
+  render() {
+    return <RCTRefreshControl />;
+  }
+}
+
+module.exports = RefreshControlMock;

Libraries/Components/ScrollView/__mocks__/ScrollViewMock.js

@@ -0,0 +1,33 @@
+/**
+ * Copyright (c) 2013-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.
+ *
+ * @flow
+ */
+'use strict';
+
+const React = require('React');
+const View = require('View');
+
+const requireNativeComponent = require('requireNativeComponent');
+
+const RCTScrollView = requireNativeComponent('RCTScrollView');
+
+class ScrollViewMock extends React.Component {
+  render() {
+    return (
+      <RCTScrollView>
+        {this.props.refreshControl}
+        <View>
+          {this.props.children}
+        </View>
+      </RCTScrollView>
+    );
+  }
+}
+
+module.exports = ScrollViewMock;

Libraries/CustomComponents/ListView/__mocks__/ListViewMock.js

@@ -0,0 +1,60 @@
+/**
+ * Copyright (c) 2013-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.
+ *
+ * @flow
+ */
+'use strict';
+
+const ListViewDataSource = require('ListViewDataSource');
+const React = require('React');
+const ScrollView = require('ScrollView');
+const StaticRenderer = require('StaticRenderer');
+const View = require('View');
+
+class ListViewMock extends React.Component {
+  static latestRef: ?ListViewMock;
+  static defaultProps = {
+    renderScrollComponent: (props) => <ScrollView {...props} />,
+  }
+  componentDidMount() {
+    ListViewMock.latestRef = this;
+  }
+  render() {
+    const {dataSource, renderFooter, renderHeader} = this.props;
+    const rows = [renderHeader && renderHeader()];
+    const allRowIDs = dataSource.rowIdentities;
+    for (let sectionIdx = 0; sectionIdx < allRowIDs.length; sectionIdx++) {
+      const sectionID = dataSource.sectionIdentities[sectionIdx];
+      const rowIDs = allRowIDs[sectionIdx];
+      for (let rowIdx = 0; rowIdx < rowIDs.length; rowIdx++) {
+        const rowID = rowIDs[rowIdx];
+        rows.push(
+          <StaticRenderer
+            key={rowID}
+            shouldUpdate={true}
+            render={this.props.renderRow.bind(
+              null,
+              dataSource.getRowData(sectionIdx, rowIdx),
+              sectionID,
+              rowID
+            )}
+          />
+        );
+      }
+    }
+    renderFooter && rows.push(renderFooter());
+    return (
+      <View>
+        {this.props.renderScrollComponent({children: rows})}
+      </View>
+    );
+  }
+  static DataSource = ListViewDataSource;
+}
+
+module.exports = ListViewMock;

jest/setup.js

@@ -33,17 +33,13 @@ jest
   .mock('TextInput', () => mockComponent('TextInput'))
   .mock('Modal', () => mockComponent('Modal'))
   .mock('View', () => mockComponent('View'))
-  .mock('ScrollView', () => mockComponent('ScrollView'))
+  .mock('RefreshControl', () => require.requireMock('RefreshControlMock'))
+  .mock('ScrollView', () => require.requireMock('ScrollViewMock'))
   .mock(
     'ActivityIndicator',
     () => mockComponent('ActivityIndicator'),
   )
-  .mock('ListView', () => {
-    const RealListView = require.requireActual('ListView');
-    const ListView = mockComponent('ListView');
-    ListView.prototype.render = RealListView.prototype.render;
-    return ListView;
-  })
+  .mock('ListView', () => require.requireMock('ListViewMock'))
   .mock('ListViewDataSource', () => {
     const DataSource = require.requireActual('ListViewDataSource');
     DataSource.prototype.toJSON = function() {