Fix #6114 - Calling setState inside getChildContext should warn

src/isomorphic/ReactDebugTool.js

@@ -11,6 +11,7 @@
 
 'use strict';
 
+var ReactInvalidSetStateWarningDevTool = require('ReactInvalidSetStateWarningDevTool');
 var warning = require('warning');
 
 var eventHandlers = [];
@@ -48,6 +49,15 @@ var ReactDebugTool = {
       }
     }
   },
+  onBeginProcessingChildContext() {
+    emitEvent('onBeginProcessingChildContext');
+  },
+  onEndProcessingChildContext() {
+    emitEvent('onEndProcessingChildContext');
+  },
+  onSetState() {
+    emitEvent('onSetState');
+  },
   onMountRootComponent(internalInstance) {
     emitEvent('onMountRootComponent', internalInstance);
   },
@@ -62,4 +72,6 @@ var ReactDebugTool = {
   },
 };
 
+ReactDebugTool.addDevtool(ReactInvalidSetStateWarningDevTool);
+
 module.exports = ReactDebugTool;

src/isomorphic/devtools/ReactInvalidSetStateWarningDevTool.js

@@ -0,0 +1,39 @@
+/**
+ * Copyright 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule ReactInvalidSetStateWarningDevTool
+ */
+
+'use strict';
+
+var warning = require('warning');
+
+if (__DEV__) {
+  var processingChildContext = false;
+
+  var warnInvalidSetState = function() {
+    warning(
+      !processingChildContext,
+      'setState(...): Cannot call setState() inside getChildContext()'
+    );
+  };
+}
+
+var ReactInvalidSetStateWarningDevTool = {
+  onBeginProcessingChildContext() {
+    processingChildContext = true;
+  },
+  onEndProcessingChildContext() {
+    processingChildContext = false;
+  },
+  onSetState() {
+    warnInvalidSetState();
+  },
+};
+
+module.exports = ReactInvalidSetStateWarningDevTool;

src/isomorphic/modern/class/ReactComponent.js

@@ -12,6 +12,7 @@
 'use strict';
 
 var ReactNoopUpdateQueue = require('ReactNoopUpdateQueue');
+var ReactInstrumentation = require('ReactInstrumentation');
 
 var canDefineProperty = require('canDefineProperty');
 var emptyObject = require('emptyObject');
@@ -66,6 +67,7 @@ ReactComponent.prototype.setState = function(partialState, callback) {
     'function which returns an object of state variables.'
   );
   if (__DEV__) {
+    ReactInstrumentation.debugTool.onSetState();
     warning(
       partialState != null,
       'setState(...): You passed an undefined or null state object; ' +