Merge 47002da into 8984fa2

helpers.js

@@ -7,3 +7,15 @@ exports.pathMatch = function(url, path) {
     return false;
   }
 }
+
+exports.createMemoizedToJson = function() {
+  var lastStats = null;
+  var lastJson = null;
+  return function(stats) {
+    if (lastStats !== stats) {
+      lastStats = stats;
+      lastJson = stats.toJson({ errorDetails: false });
+    }
+    return lastJson;
+  }
+};

middleware.js

@@ -2,6 +2,7 @@ module.exports = webpackHotMiddleware;
 
 var helpers = require('./helpers');
 var pathMatch = helpers.pathMatch;
+var statsToJson = helpers.createMemoizedToJson();
 
 function webpackHotMiddleware(compiler, opts) {
   opts = opts || {};
@@ -84,7 +85,7 @@ function createEventStream(heartbeat) {
 
 function publishStats(action, statsResult, eventStream, log) {
   // For multi-compiler, stats will be an object with a 'children' array of stats
-  var bundles = extractBundles(statsResult.toJson({ errorDetails: false }));
+  var bundles = extractBundles(statsToJson(statsResult));
   bundles.forEach(function(stats) {
     if (log) {
       log("webpack built " + (stats.name ? stats.name + " " : "") +

test/helpers-test.js

@@ -19,4 +19,25 @@ describe("helpers", function() {
       assert.equal(pathMatch("/path-and", "/path"), false);
     });
   });
+
+  describe("createMemoizedToJson", function() {
+    var stats = function() {
+      return {
+        toJson: function() {
+          return {};
+        }
+      }
+    };
+    var toJson = null;
+    beforeEach(function() {
+      toJson = helpers.createMemoizedToJson();
+    });
+    it("should return same value for same stats instance", function() {
+      var instance = stats();
+      assert.strictEqual(toJson(instance), toJson(instance));
+    });
+    it("should return same value for same stats instance", function() {
+      assert.notStrictEqual(toJson(stats()), toJson(stats()));
+    });
+  });
 });