Added possibility for only copy named methods

lib/proto.js

@@ -72,15 +72,19 @@
      * Mixin a given set of properties
      * @param prop The properties to mix in
      * @param obj [optional]
+     * @param namesList [optional] Array of names to extend with (if empty all are used)
      * The object to add the mixin
      */
-    mixin: function (prop, obj) {
+    mixin: function (prop, obj, namesList) {
       var self = obj || this;
       var fnTest = /\b_super\b/;
       var _super = Object.getPrototypeOf(self) || self.prototype;
       var descriptors = {};
       var proto = prop;
+      var names = namesList && (Array.isArray(namesList) ? namesList : [namesList]);
       var processProperty = function (name) {
+        if (names && !names.includes(name)) return;
+
         var descriptor = Object.getOwnPropertyDescriptor(proto, name);
 
         if (!descriptors[name] && descriptor) {
@@ -119,10 +123,11 @@
      * Extend the current or a given object with the given property and return the extended object.
      * @param prop The properties to extend with
      * @param obj [optional] The object to extend from
+     * @param names [optional] Array of names to extend with (if empty all are used)
      * @returns The extended object
      */
-    extend: function (prop, obj) {
-      return this.mixin(prop, Object.create(obj || this));
+    extend: function (prop, obj, names) {
+      return this.mixin(prop, Object.create(obj || this), names);
     },
     /**
      * Return a callback function with this set to the current or a given context object.

readme.md

@@ -254,6 +254,30 @@ singHello() // Laaaa Laalaaa! Helloooooo!
 
 `proxy` only works on objects extended from UberProto.
 
+### Named extend and mixin
+Both `Proto.extend()` and `Proto.mixin()` has an optional third parameter where you can name the methods and symbols you want to extend your object with e.g.:
+
+``` javascript
+operaSinger.mixin({
+	sing : function(text){
+		return this._super() + ' ' + text;
+	},
+	sang : function(text) {
+		return this.sing() + ' Lolololooo! ' + text;
+	},
+	sung : function(text) {
+		return this.sing() + ' Dodododooo! ' + text;
+	}
+}, undefined, [ 'sang', 'sing' ]);
+
+var singHello = operaSinger.proxy('sing', 'Helloooooo!');
+var sangHello = operaSinger.proxy('sang', 'Helloooooo!');
+
+singHello() // Laaaa Laalaaa! Helloooooo!
+sangHello() // Laaaa Laalaaa! Lolololooo! Helloooooo!
+var sungHello = operaSinger.proxy('sung', 'Helloooooo!'); // results in error
+```
+
 ## License
 
 MIT License

test/test.js

@@ -265,4 +265,150 @@ describe('UberProto', function () {
       assert.strictEqual(extext.sayHi(), 'Hi David Luecke!!!');
     });
   });
+
+  describe('Named extend and mixin', () => {
+    it('extends objects with name', function () {
+      var Original = {
+        sayHello () {
+          assert.ok(true, 'sayHello called');
+          return 'hello';
+        }
+      };
+      var Extended = Proto.extend(Original);
+      Extended = Extended.extend({
+        sayHi: function () {
+          assert.ok(true, 'sayHi called');
+          return 'hi';
+        },
+        sayYo: function () {
+          assert.ok(true, 'sayYo called');
+          return 'yo';
+        }
+      }, undefined, ['sayHi']);
+
+      assert.strictEqual(Extended.create().sayHi(), 'hi', 'Said hi');
+      assert.strictEqual(Extended.create().sayHello(), 'hello', 'Said hello');
+      assert.strictEqual(typeof Extended.create().sayYo, 'undefined', 'Cannot Say yo');
+    });
+
+    it('extends objects with names', function () {
+      var Original = {
+        sayHello: function () {
+          assert.ok(true, 'sayHello called');
+          return 'hello';
+        }
+      };
+      var Extended = Proto.extend(Original);
+      Extended = Extended.extend({
+        sayHi: function () {
+          assert.ok(true, 'sayHi called');
+          return 'hi';
+        },
+        sayYo: function () {
+          assert.ok(true, 'sayYo called');
+          return 'yo';
+        }
+      }, undefined, ['sayHi', 'sayYo']);
+
+      assert.strictEqual(Extended.create().sayHi(), 'hi', 'Said hi');
+      assert.strictEqual(Extended.create().sayHello(), 'hello', 'Said hello');
+      assert.strictEqual(Extended.create().sayYo(), 'yo', 'Said yo');
+    });
+
+    it('extends objects with all', function () {
+      var Original = {
+        sayHello: function () {
+          assert.ok(true, 'sayHello called');
+          return 'hello';
+        }
+      };
+      var Extended = Proto.extend(Original);
+      Extended = Extended.extend({
+        sayHi: function () {
+          assert.ok(true, 'sayHi called');
+          return 'hi';
+        },
+        sayYo: function () {
+          assert.ok(true, 'sayYo called');
+          return 'yo';
+        }
+      });
+
+      assert.strictEqual(Extended.create().sayHi(), 'hi', 'Said hi');
+      assert.strictEqual(Extended.create().sayHello(), 'hello', 'Said hello');
+      assert.strictEqual(Extended.create().sayYo(), 'yo', 'Said yo');
+    });
+
+    it('mixin objects with name', function () {
+      var Original = {
+        sayHello: function () {
+          assert.ok(true, 'sayHello called');
+          return 'hello';
+        }
+      };
+      var Mixined = Proto.mixin(Original);
+      Mixined = Mixined.mixin({
+        sayHi: function () {
+          assert.ok(true, 'sayHi called');
+          return 'hi';
+        },
+        sayYo: function () {
+          assert.ok(true, 'sayYo called');
+          return 'yo';
+        }
+      }, undefined, ['sayHi']);
+
+      assert.strictEqual(Mixined.create().sayHi(), 'hi', 'Said hi');
+      assert.strictEqual(Mixined.create().sayHello(), 'hello', 'Said hello');
+      assert.strictEqual(typeof Mixined.create().sayYo, 'undefined', 'Cannot Say yo');
+    });
+
+    it('extends objects with names', function () {
+      var Original = {
+        sayHello: function () {
+          assert.ok(true, 'sayHello called');
+          return 'hello';
+        }
+      };
+      var Mixined = Proto.mixin(Original);
+      Mixined = Mixined.mixin({
+        sayHi: function () {
+          assert.ok(true, 'sayHi called');
+          return 'hi';
+        },
+        sayYo: function () {
+          assert.ok(true, 'sayYo called');
+          return 'yo';
+        }
+      }, undefined, ['sayHi', 'sayYo']);
+
+      assert.strictEqual(Mixined.create().sayHi(), 'hi', 'Said hi');
+      assert.strictEqual(Mixined.create().sayHello(), 'hello', 'Said hello');
+      assert.strictEqual(Mixined.create().sayYo(), 'yo', 'Said yo');
+    });
+
+    it('extends objects with all', function () {
+      var Original = {
+        sayHello: function () {
+          assert.ok(true, 'sayHello called');
+          return 'hello';
+        }
+      };
+      var Mixined = Proto.mixin(Original);
+      Mixined = Mixined.mixin({
+        sayHi: function () {
+          assert.ok(true, 'sayHi called');
+          return 'hi';
+        },
+        sayYo: function () {
+          assert.ok(true, 'sayYo called');
+          return 'yo';
+        }
+      });
+
+      assert.strictEqual(Mixined.create().sayHi(), 'hi', 'Said hi');
+      assert.strictEqual(Mixined.create().sayHello(), 'hello', 'Said hello');
+      assert.strictEqual(Mixined.create().sayYo(), 'yo', 'Said yo');
+    });
+  });
 });