Improved error message wording for missing getChildContext() method

src/isomorphic/classic/__tests__/ReactContextValidator-test.js

@@ -314,7 +314,9 @@ describe('ReactContextValidator', () => {
     ReactTestUtils.renderIntoDocument(<ComponentA/>);
     expectDev(console.error.calls.count()).toBe(1);
     expectDev(normalizeCodeLocInfo(console.error.calls.argsFor(0)[0])).toBe(
-      'Warning: getChildContext() is not defined for ComponentA'
+      'Warning: ComponentA.childContextTypes is specified but there is no ' +
+      'getChildContext() method on the instance. You can either define ' +
+      'getChildContext() on ComponentA or remove childContextTypes from it.'
     );
 
     // Warnings should be deduped by component type
@@ -323,7 +325,9 @@ describe('ReactContextValidator', () => {
     ReactTestUtils.renderIntoDocument(<ComponentB/>);
     expectDev(console.error.calls.count()).toBe(2);
     expectDev(normalizeCodeLocInfo(console.error.calls.argsFor(1)[0])).toBe(
-      'Warning: getChildContext() is not defined for ComponentB'
+      'Warning: ComponentB.childContextTypes is specified but there is no ' +
+      'getChildContext() method on the instance. You can either define ' +
+      'getChildContext() on ComponentB or remove childContextTypes from it.'
     );
   });
 
@@ -332,28 +336,28 @@ describe('ReactContextValidator', () => {
   it('should pass parent context if getChildContext method is missing', () => {
     spyOn(console, 'error');
 
-    var ParentContextProvider = React.createClass({
-      childContextTypes: {
+    class ParentContextProvider extends React.Component {
+      static childContextTypes = {
         foo: React.PropTypes.number,
-      },
-      getChildContext: function() {
+      };
+      getChildContext() {
         return {
           foo: 'FOO',
         };
-      },
-      render: function() {
+      }
+      render() {
         return <MiddleMissingContext />;
-      },
-    });
+      }
+    }
 
-    var MiddleMissingContext = React.createClass({
-      childContextTypes: {
+    class MiddleMissingContext extends React.Component {
+      static childContextTypes = {
         bar: React.PropTypes.string.isRequired,
-      },
-      render: function() {
+      };
+      render() {
         return <ChildContextConsumer />;
-      },
-    });
+      }
+    }
 
     var childContext;
     var ChildContextConsumer = React.createClass({

src/renderers/shared/fiber/ReactFiberContext.js

@@ -34,7 +34,7 @@ const {
 
 if (__DEV__) {
   var checkReactTypeSpec = require('checkReactTypeSpec');
-  var warningAboutMissingGetChildContext = {};
+  var warnedAboutMissingGetChildContext = {};
 }
 
 // A cursor to the current merged context object on the stack.
@@ -150,11 +150,14 @@ function processChildContext(fiber : Fiber, parentContext : Object, isReconcilin
     if (__DEV__) {
       const componentName = getComponentName(fiber);
       
-      if (!warningAboutMissingGetChildContext[componentName]) {
-        warningAboutMissingGetChildContext[componentName] = true;
+      if (!warnedAboutMissingGetChildContext[componentName]) {
+        warnedAboutMissingGetChildContext[componentName] = true;
         warning(
           false,
-          'getChildContext() is not defined for %s',
+          '%s.childContextTypes is specified but there is no getChildContext() method ' +
+          'on the instance. You can either define getChildContext() on %s or remove ' +
+          'childContextTypes from it.',
+          componentName,
           componentName,
         );
       }

src/renderers/shared/shared/__tests__/ReactStatelessComponent-test.js

@@ -124,8 +124,10 @@ describe('ReactStatelessComponent', () => {
       'be defined on a functional component.'
     );
     expectDev(normalizeCodeLocInfo(console.error.calls.argsFor(1)[0])).toBe(
-      'Warning: getChildContext() is not defined for ' +
-      'StatelessComponentWithChildContext'
+      'Warning: StatelessComponentWithChildContext.childContextTypes is specified ' +
+      'but there is no getChildContext() method on the instance. You can either ' +
+      'define getChildContext() on StatelessComponentWithChildContext or remove ' +
+      'childContextTypes from it.'
     );
   });
 

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

@@ -707,7 +707,10 @@ var ReactCompositeComponent = {
           warningAboutMissingGetChildContext[componentName] = true;
           warning(
             !Component.childContextTypes,
-            'getChildContext() is not defined for %s',
+            '%s.childContextTypes is specified but there is no getChildContext() method ' +
+            'on the instance. You can either define getChildContext() on %s or remove ' +
+            'childContextTypes from it.',
+            componentName,
             componentName,
           );
         }