Add a simple fabric component example

Summary:
This diff adds a very simple example to show the use of new architecture in a component.

Changelog: [internal]

Reviewed By: cortinico

Differential Revision: D32045059

fbshipit-source-id: f388bfb765241122de425fbef61cea0620cd31ac

packages/rn-tester/NativeComponentExample/js/MyNativeViewNativeComponent.js

@@ -0,0 +1,38 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import codegenNativeComponent from 'react-native/Libraries/Utilities/codegenNativeComponent';
+import codegenNativeCommands from 'react-native/Libraries/Utilities/codegenNativeCommands';
+import type {HostComponent} from 'react-native/Libraries/Renderer/shims/ReactNativeTypes';
+import type {ViewProps} from 'react-native/Libraries/Components/View/ViewPropTypes';
+import type {Float} from 'react-native/Libraries/Types/CodegenTypes';
+import * as React from 'react';
+
+type NativeProps = $ReadOnly<{|
+  ...ViewProps,
+  opacity?: Float,
+|}>;
+
+export type MyNativeViewType = HostComponent<NativeProps>;
+
+interface NativeCommands {
+  +callNativeMethodToChangeBackgroundColor: (
+    viewRef: React.ElementRef<MyNativeViewType>,
+    color: string,
+  ) => void;
+}
+
+export const Commands: NativeCommands = codegenNativeCommands<NativeCommands>({
+  supportedCommands: ['callNativeMethodToChangeBackgroundColor'],
+});
+
+export default (codegenNativeComponent<NativeProps>(
+  'RNTMyNativeView',
+): MyNativeViewType);