renderComponentToString memory leak fix for #954

src/environment/ReactServerRendering.js

@@ -22,6 +22,7 @@ var ReactComponent = require('ReactComponent');
 var ReactInstanceHandles = require('ReactInstanceHandles');
 var ReactMarkupChecksum = require('ReactMarkupChecksum');
 var ReactReconcileTransaction = require('ReactReconcileTransaction');
+var EventPluginHub = require('EventPluginHub');
 
 var invariant = require('invariant');
 
@@ -48,7 +49,10 @@ function renderComponentToString(component, callback) {
   transaction.reinitializeTransaction();
   try {
     transaction.perform(function() {
+      var registrationEnabled = EventPluginHub.isRegistrationEnabled();
+      EventPluginHub.setRegistrationEnabled(false);
       var markup = component.mountComponent(id, transaction, 0);
+      EventPluginHub.setRegistrationEnabled(registrationEnabled);
       markup = ReactMarkupChecksum.addChecksumToMarkup(markup);
       callback(markup);
     }, null);

src/environment/__tests__/ReactServerRendering-test.js

@@ -27,7 +27,8 @@ require('mock-modules')
   .dontMock('ReactMount')
   .dontMock('ReactServerRendering')
   .dontMock('ReactTestUtils')
-  .dontMock('ReactMarkupChecksum');
+  .dontMock('ReactMarkupChecksum')
+  .dontMock('EventPluginHub');
 
 var mocks = require('mocks');
 
@@ -37,6 +38,7 @@ var ReactTestUtils;
 var ReactServerRendering;
 var ReactMarkupChecksum;
 var ExecutionEnvironment;
+var EventPluginHub;
 
 var ID_ATTRIBUTE_NAME;
 
@@ -50,6 +52,7 @@ describe('ReactServerRendering', function() {
     ExecutionEnvironment.canUseDOM = false;
     ReactServerRendering = require('ReactServerRendering');
     ReactMarkupChecksum = require('ReactMarkupChecksum');
+    EventPluginHub = require('EventPluginHub');
 
     var DOMProperty = require('DOMProperty');
     ID_ATTRIBUTE_NAME = DOMProperty.ID_ATTRIBUTE_NAME;
@@ -234,6 +237,43 @@ describe('ReactServerRendering', function() {
     expect(numClicks).toEqual(1);
   });
 
+  it('should not register listeners', function() {
+    var Link = React.createClass({
+      handleClick: function() {},
+      render: function() {
+        return <a onClick={this.handleClick}>link</a>;
+      }
+    });
+    var link = <Link />;
+    ReactServerRendering.renderComponentToString(link, function(str) {
+      var listener = EventPluginHub.getListener(link._rootNodeID, 'onClick');
+      expect(listener).not.toEqual(link.handleClick);
+    });
+  });
+
+  // White box ReactServerRendering, black box EventPluginHub
+  describe('event listener registration', function() {
+    var cb;
+    beforeEach(function() {
+      cb = mocks.getMockFunction();
+    });
+    it('should preserve default', function() {
+      var def = EventPluginHub.isRegistrationEnabled();
+      ReactServerRendering.renderComponentToString(<span />, cb);
+      expect(EventPluginHub.isRegistrationEnabled()).toEqual(def);
+    });
+    it('should preserve true', function() {
+      EventPluginHub.setRegistrationEnabled(false);
+      ReactServerRendering.renderComponentToString(<span />, cb);
+      expect(EventPluginHub.isRegistrationEnabled()).toEqual(false);
+    });
+    it('should preserve false', function() {
+      EventPluginHub.setRegistrationEnabled(true);
+      ReactServerRendering.renderComponentToString(<span />, cb);
+      expect(EventPluginHub.isRegistrationEnabled()).toEqual(true);
+    });
+  });
+
   it('should throw with silly args', function() {
     expect(
       ReactServerRendering.renderComponentToString.bind(

src/event/EventPluginHub.js

@@ -31,6 +31,11 @@ var isEventSupported = require('isEventSupported');
  */
 var listenerBank = {};
 
+/**
+ *  Allow disabling listener registration
+ */
+var registrationEnabled = true;
+
 /**
  * Internal queue of events that have accumulated their dispatches and are
  * waiting to have their dispatches executed.
@@ -98,6 +103,24 @@ function validateInstanceHandle() {
  */
 var EventPluginHub = {
 
+  /**
+   * `setRegistrationEnabled` allows temporary disabling of event registration
+   *
+   * @param {boolean} enabled Enable or disable the registration of listeners
+   * @public
+   */
+  setRegistrationEnabled: function(enabled) {
+    registrationEnabled = enabled;
+  },
+
+  /**
+   * @return {boolean} Returns whether or not registering listeners is enabled
+   * @public
+   */
+  isRegistrationEnabled: function() {
+    return registrationEnabled;
+  },
+
   /**
    * Methods for injecting dependencies.
    */
@@ -158,9 +181,11 @@ var EventPluginHub = {
         console.warn('This browser doesn\'t support the `onScroll` event');
       }
     }
-    var bankForRegistrationName =
-      listenerBank[registrationName] || (listenerBank[registrationName] = {});
-    bankForRegistrationName[id] = listener;
+    if(registrationEnabled) {
+      var bankForRegistrationName =
+        listenerBank[registrationName] || (listenerBank[registrationName] = {});
+      bankForRegistrationName[id] = listener;
+    }
   },
 
   /**

src/event/__tests__/EventPluginHub-test.js

@@ -22,6 +22,9 @@ require('mock-modules')
   .dontMock('EventPluginHub')
   .mock('isEventSupported');
 
+var keyOf = require('keyOf');
+var mocks = require('mocks');
+
 describe('EventPluginHub', function() {
   var EventPluginHub;
   var isEventSupported;
@@ -33,6 +36,45 @@ describe('EventPluginHub', function() {
     isEventSupported.mockReturnValue(false);
   });
 
+  describe('event registration', function() {
+    var id, key, listener;
+    beforeEach(function() {
+      id = '.reactRoot.[0].[0].[0]';
+      key = keyOf({onClick: null});
+      listener = mocks.getMockFunction();
+    });
+    it('should be enabled by default', function() {
+      expect(EventPluginHub.isRegistrationEnabled()).toEqual(true);
+    });
+    describe('disabled', function() {
+      beforeEach(function() {
+        EventPluginHub.setRegistrationEnabled(false);
+      });
+      it('should not register listeners', function() {
+        EventPluginHub.setRegistrationEnabled(false);
+        EventPluginHub.putListener(id, key, listener);
+        var registeredListener = EventPluginHub.getListener(id, key);
+        expect(registeredListener).not.toEqual(listener);
+      });
+      it('should report', function() {
+        expect(EventPluginHub.isRegistrationEnabled()).toEqual(false);
+      });
+    });
+    describe('enabled', function() {
+      beforeEach(function() {
+        EventPluginHub.setRegistrationEnabled(true);
+      });
+      it('should register listeners', function() {
+        EventPluginHub.putListener(id, key, listener);
+        var registeredListener = EventPluginHub.getListener(id, key);
+        expect(registeredListener).toEqual(listener);
+      });
+      it('should report', function() {
+        expect(EventPluginHub.isRegistrationEnabled()).toEqual(true);
+      });
+    });
+  });
+
   it('should warn about the `onScroll` issue on IE8', function() {
     spyOn(console, 'warn');
     EventPluginHub.putListener(1, 'onScroll', function(){});