Treat arguments objects like plain objects.

lodash.src.js

@@ -1826,10 +1826,7 @@
         var tag = objToString.call(value),
             isFunc = tag == funcTag;
 
-        if (!lodash.support.argsTag && isArguments(value)) {
+        if (tag == argsTag || tag == objectTag || (isFunc && !object)) {
-          tag = argsTag;
-        }
-        if (tag == objectTag || (isFunc && !object)) {
           if (isHostObject(value)) {
             return object ? value : {};
           }
@@ -2289,24 +2286,18 @@
 
       if (!objIsArr) {
         objTag = objToString.call(object);
-        if (isLength(object.length)) {
+        if (objTag == argsTag) {
-          if (isArguments(object)) {
+          objTag = objectTag;
-            object = arrayToObject(object);
+        } else if (objTag != objectTag) {
-            objTag = objectTag;
+          objIsArr = isTypedArray(object);
-          } else if (objTag != objectTag) {
-            objIsArr = isTypedArray(object);
-          }
         }
       }
       if (!othIsArr) {
         othTag = objToString.call(other);
-        if (isLength(other.length)) {
+        if (othTag == argsTag) {
-          if (isArguments(other)) {
+          othTag = objectTag;
-            other = arrayToObject(other);
+        } else if (othTag != objectTag) {
-            othTag = objectTag;
+          othIsArr = isTypedArray(other);
-          } else if (othTag != objectTag) {
-            othIsArr = isTypedArray(other);
-          }
         }
       }
       var objIsObj = objTag == objectTag && !isHostObject(object),
@@ -2528,7 +2519,7 @@
         }
         else if (isPlainObject(srcValue) || isArguments(srcValue)) {
           result = isArguments(value)
-            ? arrayToObject(value)
+            ? toPlainObject(value)
             : (isPlainObject(value) ? value : {});
         }
       }
@@ -3666,11 +3657,6 @@
     function initCloneByTag(object, tag, isDeep) {
       var Ctor = object.constructor;
       switch (tag) {
-        case argsTag:
-          var result = new Ctor;
-          result.length = object.length;
-          return arrayCopy(object, result);
-
         case arrayBufferTag:
           return bufferClone(object);
 
@@ -3693,7 +3679,7 @@
           return new Ctor(object);
 
         case regexpTag:
-          result = new Ctor(object.source, reFlags.exec(object));
+          var result = new Ctor(object.source, reFlags.exec(object));
           result.lastIndex = object.lastIndex;
       }
       return result;
@@ -4031,17 +4017,6 @@
       return result;
     }
 
-    /**
-     * Converts `array` to a plain array-like object.
-     *
-     * @private
-     * @param {Array} array The array to convert.
-     * @returns {Object} Returns the converted object.
-     */
-    function arrayToObject(array) {
-      return arrayCopy(array, { 'length': array.length });
-    }
-
     /**
      * Converts `value` to an array-like object if it is not one.
      *
@@ -8366,9 +8341,7 @@
      * // => { 'a': 1, 'b': 2, 'c': 3 }
      */
     function toPlainObject(value) {
-      return (isArray(value) || isArguments(value) || isTypedArray(value))
+      return baseCopy(value, keysIn(value));
-        ? arrayToObject(value)
-        : baseCopy(value, keysIn(value));
     }
 
     /*------------------------------------------------------------------------*/

test/test.js

@@ -1786,9 +1786,10 @@
       });
 
       test('`_.' + methodName + '` should clone array buffers', 2, function() {
-        var buffer = ArrayBuffer && new ArrayBuffer(10);
+        if (ArrayBuffer) {
-        if (buffer) {
+          var buffer = new ArrayBuffer(10),
-          var actual = func(buffer);
+              actual = func(buffer);
+
           strictEqual(actual.byteLength, buffer.byteLength);
           notStrictEqual(actual, buffer);
         }
@@ -6585,7 +6586,7 @@
 
     test('should treat `arguments` objects like `Object` objects', 4, function() {
       var args = (function() { return arguments; }(1, 2, 3)),
-          object = { '0': 1, '1': 2, '2': 3, 'length': 3 };
+          object = { '0': 1, '1': 2, '2': 3 };
 
       function Foo() {}
       Foo.prototype = object;
@@ -8927,7 +8928,7 @@
     test('should merge `arguments` objects', 3, function() {
       var object1 = { 'value': args },
           object2 = { 'value': { '3': 4 } },
-          expected = { '0': 1, '1': 2, '2': 3, '3': 4, 'length': 3 },
+          expected = { '0': 1, '1': 2, '2': 3, '3': 4 },
           actual = _.merge(object1, object2);
 
       ok(!_.isArguments(actual.value));
@@ -8947,9 +8948,9 @@
       var arrays = [array2, array1, array4, array3, array2, array4, array4, array3, array2],
           buffer = ArrayBuffer && new ArrayBuffer(8);
 
-      if (root.Float64Array) {
+      // juggle for `Float64Array` shim
-        // juggle for `Float64Array` shim
+      if (root.Float64Array && (new Float64Array(buffer)).length == 8) {
-        arrays[1] = _.size(new Float64Array(buffer)) > 1 ? array4 : array1;
+        arrays[1] = array4;
       }
       var expected = _.map(typedArrays, function(type, index) {
         var array = arrays[index].slice();
@@ -13213,30 +13214,30 @@
 
     test('should convert `arguments` objects to plain objects', 1, function() {
       var actual = _.toPlainObject(args),
-          expected = { '0': 1, '1': 2, '2': 3, 'length': 3 };
+          expected = { '0': 1, '1': 2, '2': 3 };
 
       deepEqual(actual, expected);
     });
 
     test('should convert arrays to plain objects', 1, function() {
       var actual = _.toPlainObject(['a', 'b', 'c']),
-          expected = { '0': 'a', '1': 'b', '2': 'c', 'length': 3 };
+          expected = { '0': 'a', '1': 'b', '2': 'c' };
 
       deepEqual(actual, expected);
     });
 
     test('should convert typed arrays to plain objects', 1, function() {
-      var object1 = { '0': 0, 'length': 1 },
+      var object1 = { '0': 0 },
-          object2 = { '0': 0, '1': 0, 'length': 2 },
+          object2 = { '0': 0, '1': 0 },
-          object3 = { '0': 0, '1': 0, '2': 0, '3': 0, 'length': 4 },
+          object3 = { '0': 0, '1': 0, '2': 0, '3': 0 },
-          object4 = { '0': 0, '1': 0, '2': 0, '3': 0, '4': 0, '5': 0, '6': 0, '7': 0, 'length': 8 };
+          object4 = { '0': 0, '1': 0, '2': 0, '3': 0, '4': 0, '5': 0, '6': 0, '7': 0 };
 
       var objects = [object2, object1, object4, object3, object2, object4, object4, object3, object2],
           buffer = ArrayBuffer && new ArrayBuffer(8);
 
-      if (root.Float64Array) {
+      // juggle for `Float64Array` shim
-        // juggle for `Float64Array` shim
+      if (root.Float64Array && (new Float64Array(buffer)).length == 8) {
-        objects[1] = _.size(new Float64Array(buffer)) > 1 ? object4 : object1;
+        objects[1] = object4;
       }
       var expected = _.map(typedArrays, function(type, index) {
         return root[type] ? objects[index] : false;