class B extends A calls A.extended(B)

lib/nodes.js

@@ -1668,7 +1668,7 @@
     }
   });
   UTILITIES = {
-    'extends': "function(child, parent) {\n    var ctor = function(){ };\n    ctor.prototype = parent.prototype;\n    child.__superClass__ = parent.prototype;\n    child.prototype = new ctor();\n    child.prototype.constructor = child;\n  }",
+    'extends': "function(child, parent) {\n    var ctor = function(){ };\n    ctor.prototype = parent.prototype;\n    child.prototype = new ctor();\n    child.prototype.constructor = child;\n    if (typeof parent.extended === \"function\") parent.extended(child);\n    child.__superClass__ = parent.prototype;\n  }",
     hasProp: 'Object.prototype.hasOwnProperty',
     slice: 'Array.prototype.slice'
   };

src/nodes.coffee

@@ -1479,9 +1479,10 @@ UTILITIES: {
             function(child, parent) {
                 var ctor = function(){ };
                 ctor.prototype = parent.prototype;
-                child.__superClass__ = parent.prototype;
                 child.prototype = new ctor();
                 child.prototype.constructor = child;
+                if (typeof parent.extended === "function") parent.extended(child);
+                child.__superClass__ = parent.prototype;
               }
             """
 

test/test_classes.coffee

@@ -183,3 +183,26 @@ c: new Child
 c.method 1, 2, 3, 4
 ok c.args.join(' ') is '1 2 3 4'
 
+
+# Test `extended` callback.
+class Base
+  @extended: (subclass) ->
+    for key, value of @
+      subclass[key]: value
+
+class Element extends Base
+  @fromHTML: (html) ->
+    node: "..."
+    new @(node)
+
+  constructor: (node) ->
+    @node: node
+
+ok Element.extended is Base.extended
+ok Element.__superClass__ is Base.prototype
+
+class MyElement extends Element
+
+ok MyElement.extended is Base.extended
+ok MyElement.fromHTML is Element.fromHTML
+ok MyElement.__superClass__ is Element.prototype