Allow _.mixin to accept a destination object as well as a source object.

Former-commit-id: 11ccb77653f017270c07579f59d75b847d4e6c65

build.js

@@ -153,7 +153,7 @@
     'memoize': [],
     'merge': ['createCallback', 'forEach', 'forOwn', 'getArray', 'isArray', 'isObject', 'isPlainObject', 'releaseArray'],
     'min': ['basicEach', 'charAtCallback', 'createCallback', 'isArray', 'isString'],
-    'mixin': ['forEach', 'functions'],
+    'mixin': ['forEach', 'functions', 'isFunction'],
     'noConflict': [],
     'omit': ['basicFlatten', 'createCallback', 'forIn', 'getIndexOf'],
     'once': [],
@@ -2716,6 +2716,9 @@
           }
         });
       }
+      if (_.contains(plusFuncs, 'chain') == !isUnderscore) {
+        funcDependencyMap.mixin = _.without(funcDependencyMap.mixin, 'isFunction');
+      }
       if (isUnderscore) {
         if (!isLodash('clone') && !isLodash('cloneDeep')) {
           funcDependencyMap.clone = _.without(funcDependencyMap.clone, 'forEach', 'forOwn');

lodash.js

@@ -485,6 +485,7 @@
     /** Native method shortcuts */
     var ceil = Math.ceil,
         clearTimeout = context.clearTimeout,
+        defineProperty = reNative.test(defineProperty = Object.defineProperty) && defineProperty,
         floor = Math.floor,
         fnToString = Function.prototype.toString,
         getPrototypeOf = reNative.test(getPrototypeOf = Object.getPrototypeOf) && getPrototypeOf,
@@ -5223,20 +5224,26 @@
      * _('moe').capitalize();
      * // => 'Moe'
      */
-    function mixin(object) {
-      forEach(functions(object), function(methodName) {
-        var func = lodash[methodName] = object[methodName];
+    function mixin(object, source) {
+      if (!source) {
+        source = object;
+        object = lodash;
+      }
+      var isFunc = isFunction(object);
+      forEach(functions(source), function(methodName) {
+        var func = object[methodName] = source[methodName];
+        if (isFunc) {
+          object.prototype[methodName] = function() {
+            var value = this.__wrapped__,
+                args = [value];
 
-        lodash.prototype[methodName] = function() {
-          var value = this.__wrapped__,
-              args = [value];
-
-          push.apply(args, arguments);
-          var result = func.apply(lodash, args);
-          return (value && typeof value == 'object' && value === result)
-            ? this
-            : new lodashWrapper(result);
-        };
+            push.apply(args, arguments);
+            var result = func.apply(object, args);
+            return (value && typeof value == 'object' && value === result)
+              ? this
+              : new lodashWrapper(result);
+          };
+        }
       });
     }
 

test/test.js

@@ -2234,6 +2234,24 @@
 
   /*--------------------------------------------------------------------------*/
 
+  QUnit.module('lodash.mixin');
+
+  (function() {
+    test('should accept an `object` argument', function() {
+      var lodash = {};
+      _.mixin(lodash, { 'a': function(a) { return a[0]; } });
+      strictEqual(lodash.a(['a']), 'a');
+    });
+
+    test('should accept a function `object` argument', function() {
+      var lodash = _.runInContext();
+      _.mixin(lodash, { 'a': function(a) { return a[0]; } });
+      strictEqual(lodash(['a']).a().value(), 'a');
+    });
+  }());
+
+  /*--------------------------------------------------------------------------*/
+
   QUnit.module('lodash.omit');
 
   (function() {