Update Flow and fix issues (#8006)

src/renderers/dom/fiber/ReactDOMFiber.js

@@ -54,9 +54,10 @@ var DOMRenderer = ReactFiberReconciler({
   createInstance(type : string, props : Props, children : HostChildren<Instance | TextInstance>) : Instance {
     const domElement = document.createElement(type);
     recursivelyAppendChildren(domElement, children);
-    if (typeof props.children === 'string' ||
-        typeof props.children === 'number') {
+    if (typeof props.children === 'string') {
       domElement.textContent = props.children;
+    } else if (typeof props.children === 'number') {
+      domElement.textContent = props.children.toString();
     }
     return domElement;
   },
@@ -70,9 +71,10 @@ var DOMRenderer = ReactFiberReconciler({
   },
 
   commitUpdate(domElement : Instance, oldProps : Props, newProps : Props) : void {
-    if (typeof newProps.children === 'string' ||
-        typeof newProps.children === 'number') {
+    if (typeof newProps.children === 'string') {
       domElement.textContent = newProps.children;
+    } else if (typeof newProps.children === 'number') {
+      domElement.textContent = newProps.children.toString();
     }
   },
 

src/renderers/native/NativeMethodsMixin.js

@@ -212,7 +212,7 @@ function mountSafeCallback(
   callback: ?Function
 ): any {
   return function() {
-    if (!callback || (context.isMounted && !context.isMounted())) {
+    if (!callback || (typeof context.isMounted === 'function' && !context.isMounted())) {
       return undefined;
     }
     return callback.apply(context, arguments);

src/renderers/shared/ReactDebugTool.js

@@ -239,7 +239,6 @@ function resumeCurrentLifeCycleTimer() {
 
 var lastMarkTimeStamp = 0;
 var canUsePerformanceMeasure: boolean =
-// $FlowFixMe https://github.com/facebook/flow/issues/2345
   typeof performance !== 'undefined' &&
   typeof performance.mark === 'function' &&
   typeof performance.clearMarks === 'function' &&

src/renderers/shared/fiber/ReactFiberBeginWork.js

@@ -369,7 +369,7 @@ module.exports = function<T, P, I, TI, C>(config : HostConfig<T, P, I, TI, C>, s
         // next one immediately.
         return workInProgress.child;
       case HostComponent:
-        if (workInProgress.stateNode && config.beginUpdate) {
+        if (workInProgress.stateNode && typeof config.beginUpdate === 'function') {
           config.beginUpdate(workInProgress.stateNode);
         }
         return updateHostComponent(current, workInProgress);

src/renderers/shared/stack/reconciler/ReactInstanceType.js

@@ -12,22 +12,27 @@
 
 'use strict';
 
+import type {ReactElement} from 'ReactElementType';
+
 export type DebugID = number;
 
 export type ReactInstance = {
-  // ReactCompositeComponent
+  // Shared
   mountComponent: any,
+  unmountComponent: any,
+  receiveComponent: any,
+  getName: () => string,
+  getPublicInstance: any,
+  _currentElement: ReactElement,
+
+  // ReactCompositeComponent
   performInitialMountWithErrorHandling: any,
   performInitialMount: any,
   getHostNode: any,
-  unmountComponent: any,
-  receiveComponent: any,
   performUpdateIfNecessary: any,
   updateComponent: any,
   attachRef: (ref: string, component: ReactInstance) => void,
   detachRef: (ref: string) => void,
-  getName: () => string,
-  getPublicInstance: any,
   _rootNodeID: number,
 
   // ReactDOMComponent

src/renderers/shared/utils/ReactErrorUtils.js

@@ -77,7 +77,6 @@ if (__DEV__) {
       var evtType = `react-${name}`;
       fakeNode.addEventListener(evtType, boundFunc, false);
       var evt = document.createEvent('Event');
-      // $FlowFixMe https://github.com/facebook/flow/issues/2336
       evt.initEvent(evtType, false, false);
       fakeNode.dispatchEvent(evt);
       fakeNode.removeEventListener(evtType, boundFunc, false);

src/renderers/testing/ReactTestMount.js

@@ -20,10 +20,8 @@ var getHostComponentFromComposite = require('getHostComponentFromComposite');
 var instantiateReactComponent = require('instantiateReactComponent');
 var invariant = require('invariant');
 
-import type { ReactElement } from 'ReactElementType';
-
 export type TestRendererOptions = {
-  createNodeMock: (element: ReactElement) => any,
+  createNodeMock: (element: ReactElement<any>) => any,
 };
 
 var defaultTestOptions = {