React Native: run Relay DevTools runtime

Reviewed By: fkgozali

Differential Revision: D5589121

fbshipit-source-id: 8324e123c0786a7864aaa5ebaa7134ca6afa5c18

Libraries/Core/Devtools/setupDevtools.js

@@ -11,30 +11,54 @@
  */
 'use strict';
 
+type DevToolsPluginConnection = {
+  isAppActive: () => boolean,
+  host: string,
+  port: number,
+};
+
+type DevToolsPlugin = {
+  connectToDevTools: (connection: DevToolsPluginConnection) => void,
+};
+
+let register = function () {
+  // noop
+};
+
 if (__DEV__) {
   const AppState = require('AppState');
   const WebSocket = require('WebSocket');
   const {PlatformConstants} = require('NativeModules');
-  const {connectToDevTools} = require('react-devtools-core');
+  const reactDevTools = require('react-devtools-core');
+
+  register = function (plugin: DevToolsPlugin) {
+    // Initialize dev tools only if the native module for WebSocket is available
+    if (WebSocket.isAvailable) {
+      // Don't steal the DevTools from currently active app.
+      // Note: if you add any AppState subscriptions to this file,
+      // you will also need to guard against `AppState.isAvailable`,
+      // or the code will throw for bundles that don't have it.
+      const isAppActive = () => AppState.currentState !== 'background';
 
-  // Initialize dev tools only if the native module for WebSocket is available
-  if (WebSocket.isAvailable) {
-    connectToDevTools({
-      isAppActive() {
-        // Don't steal the DevTools from currently active app.
-        // Note: if you add any AppState subscriptions to this file,
-        // you will also need to guard against `AppState.isAvailable`,
-        // or the code will throw for bundles that don't have it.
-        return AppState.currentState !== 'background';
-      },
       // Special case: Genymotion is running on a different host.
-      host: PlatformConstants && PlatformConstants.ServerHost ?
+      const host = PlatformConstants && PlatformConstants.ServerHost ?
         PlatformConstants.ServerHost.split(':')[0] :
-        'localhost',
-      // Read the optional global variable for backward compatibility.
-      // It was added in https://github.com/facebook/react-native/commit/bf2b435322e89d0aeee8792b1c6e04656c2719a0.
-      port: window.__REACT_DEVTOOLS_PORT__,
-      resolveRNStyle: require('flattenStyle'),
-    });
-  }
+        'localhost';
+
+      plugin.connectToDevTools({
+        isAppActive,
+        host,
+        // Read the optional global variable for backward compatibility.
+        // It was added in https://github.com/facebook/react-native/commit/bf2b435322e89d0aeee8792b1c6e04656c2719a0.
+        port: window.__REACT_DEVTOOLS_PORT__,
+        resolveRNStyle: require('flattenStyle'),
+      });
+    }
+  };
+
+  register(reactDevTools);
 }
+
+module.exports = {
+  register,
+};