Added global hooks.

Author: Vlad Balin

backend/backend.js

@@ -24,10 +24,13 @@
 'use strict';
 
 import type {Hook} from './types';
+import attachInnerStateInspectors from './innerStateInspectors';
 
 var attachRenderer = require('./attachRenderer');
 
 module.exports = function setupBackend(hook: Hook): boolean {
+  attachInnerStateInspectors( hook );
+
   var oldReact = window.React && window.React.__internals;
   if (oldReact && Object.keys(hook._renderers).length === 0) {
     hook.inject(oldReact);

backend/innerStateInspectors.js

@@ -0,0 +1,18 @@
+/**
+ * @flow
+ *
+ * Inner state inspectors for the built in JS data types.
+ */
+
+'use strict';
+
+import type {Hook} from './types';
+
+export default
+function attachInnerStateInspectors({ addInnerStateInspector } : Hook ) {
+  addInnerStateInspector( Date, ( x : Date ) => ({
+    local : `${ x.toDateString() } ${ x.toTimeString() }`,
+    iso : x.toISOString(),
+    timestamp : x.getTime(),
+  }), true );
+}

backend/installGlobalHook.js

@@ -198,6 +198,17 @@ function installGlobalHook(window: Object) {
         hook._listeners[evt].map(fn => fn(data));
       }
     },
+    addInnerStateInspector: function(Ctor, getInnerState, skipIfDefined) {
+      if ( !( skipIfDefined && Ctor.prototype.hasOwnProperty( '__inner_state__' ) ) ) {
+        Object.defineProperty(Ctor.prototype, '__inner_state__', ({
+          get: function() {
+            return getInnerState(this);
+          },
+          enumerable: false,
+          configurable: true,
+        } : Object ));
+      }
+    },
     // Fiber-only:
     supportsFiber: true,
     _fiberRoots: {},

backend/types.js

@@ -98,6 +98,7 @@ export type Helpers = {
 };
 
 export type Handler = (data: any) => void;
+export type InnerStateInspector = (data: any) => any;
 
 export type Hook = {
   _renderers: {[key: string]: ReactRenderer},
@@ -110,4 +111,5 @@ export type Hook = {
   off: (evt: string, handler: Handler) => void,
   reactDevtoolsAgent?: ?Object,
   getFiberRoots: (rendererID : string) => Set<Object>,
+  addInnerStateInspector: ( Ctor : Function, handler : InnerStateInspector, skipIfDefined? : boolean ) => void,
 };