Adding support for cloning and comparing DataView.

lodash.js

@@ -86,6 +86,7 @@
       weakSetTag = '[object WeakSet]';
 
   var arrayBufferTag = '[object ArrayBuffer]',
+      dataViewTag = '[object DataView]',
       float32Tag = '[object Float32Array]',
       float64Tag = '[object Float64Array]',
       int8Tag = '[object Int8Array]',
@@ -232,7 +233,7 @@
 
   /** Used to assign default `context` object properties. */
   var contextProps = [
-    'Array', 'Buffer', 'Date', 'Error', 'Float32Array', 'Float64Array',
+    'Array', 'Buffer', 'DataView', 'Date', 'Error', 'Float32Array', 'Float64Array',
     'Function', 'Int8Array', 'Int16Array', 'Int32Array', 'Map', 'Math', 'Object',
     'Promise', 'Reflect', 'RegExp', 'Set', 'String', 'Symbol', 'TypeError',
     'Uint8Array', 'Uint8ClampedArray', 'Uint16Array', 'Uint32Array', 'WeakMap',
@@ -251,25 +252,26 @@
   typedArrayTags[uint32Tag] = true;
   typedArrayTags[argsTag] = typedArrayTags[arrayTag] =
   typedArrayTags[arrayBufferTag] = typedArrayTags[boolTag] =
-  typedArrayTags[dateTag] = typedArrayTags[errorTag] =
+  typedArrayTags[dataViewTag] = typedArrayTags[dateTag] =
-  typedArrayTags[funcTag] = typedArrayTags[mapTag] =
+  typedArrayTags[errorTag] = typedArrayTags[funcTag] =
-  typedArrayTags[numberTag] = typedArrayTags[objectTag] =
+  typedArrayTags[mapTag] = typedArrayTags[numberTag] =
-  typedArrayTags[regexpTag] = typedArrayTags[setTag] =
+  typedArrayTags[objectTag] = typedArrayTags[regexpTag] =
-  typedArrayTags[stringTag] = typedArrayTags[weakMapTag] = false;
+  typedArrayTags[setTag] = typedArrayTags[stringTag] =
+  typedArrayTags[weakMapTag] = false;
 
   /** Used to identify `toStringTag` values supported by `_.clone`. */
   var cloneableTags = {};
   cloneableTags[argsTag] = cloneableTags[arrayTag] =
-  cloneableTags[arrayBufferTag] = cloneableTags[boolTag] =
+  cloneableTags[arrayBufferTag] = cloneableTags[dataViewTag] =
-  cloneableTags[dateTag] = cloneableTags[float32Tag] =
+  cloneableTags[boolTag] = cloneableTags[dateTag] =
-  cloneableTags[float64Tag] = cloneableTags[int8Tag] =
+  cloneableTags[float32Tag] = cloneableTags[float64Tag] =
-  cloneableTags[int16Tag] = cloneableTags[int32Tag] =
+  cloneableTags[int8Tag] = cloneableTags[int16Tag] =
-  cloneableTags[mapTag] = cloneableTags[numberTag] =
+  cloneableTags[int32Tag] = cloneableTags[mapTag] =
-  cloneableTags[objectTag] = cloneableTags[regexpTag] =
+  cloneableTags[numberTag] = cloneableTags[objectTag] =
-  cloneableTags[setTag] = cloneableTags[stringTag] =
+  cloneableTags[regexpTag] = cloneableTags[setTag] =
-  cloneableTags[symbolTag] = cloneableTags[uint8Tag] =
+  cloneableTags[stringTag] = cloneableTags[symbolTag] =
-  cloneableTags[uint8ClampedTag] = cloneableTags[uint16Tag] =
+  cloneableTags[uint8Tag] = cloneableTags[uint8ClampedTag] =
-  cloneableTags[uint32Tag] = true;
+  cloneableTags[uint16Tag] = cloneableTags[uint32Tag] = true;
   cloneableTags[errorTag] = cloneableTags[funcTag] =
   cloneableTags[weakMapTag] = false;
 
@@ -3969,6 +3971,19 @@
       return result;
     }
 
+    /**
+     * Creates a clone of `dataView`.
+     *
+     * @private
+     * @param {Object} dataView The data view to clone.
+     * @param {boolean} [isDeep] Specify a deep clone.
+     * @returns {Object} Returns the cloned data view.
+     */
+    function cloneDataView(dataView, isDeep) {
+      var buffer = isDeep ? cloneArrayBuffer(dataView.buffer) : dataView.buffer;
+      return new dataView.constructor(buffer, dataView.byteOffset, dataView.byteLength);
+    }
+
     /**
      * Creates a clone of `map`.
      *
@@ -4909,6 +4924,14 @@
      */
     function equalByTag(object, other, tag, equalFunc, customizer, bitmask, stack) {
       switch (tag) {
+        case dataViewTag:
+          if ((object.byteLength != other.byteLength) ||
+              (object.byteOffset != other.byteOffset)) {
+            return false;
+          }
+          object = object.buffer;
+          other = other.buffer;
+
         case arrayBufferTag:
           if ((object.byteLength != other.byteLength) ||
               !equalFunc(new Uint8Array(object), new Uint8Array(other))) {
@@ -5363,6 +5386,9 @@
         case dateTag:
           return new Ctor(+object);
 
+        case dataViewTag:
+          return cloneDataView(object, isDeep);
+
         case float32Tag: case float64Tag:
         case int8Tag: case int16Tag: case int32Tag:
         case uint8Tag: case uint8ClampedTag: case uint16Tag: case uint32Tag:

test/test.js

@@ -62,6 +62,7 @@
 
   var ArrayBuffer = root.ArrayBuffer,
       Buffer = root.Buffer,
+      DataView = root.DataView,
       Promise = root.Promise,
       Map = root.Map,
       Set = root.Set,
@@ -179,6 +180,9 @@
     'Uint32Array'
   ];
 
+  /** Used to check whether methods support array views. */
+  var arrayViews = typedArrays.concat('DataView');
+
   /** The file path of the lodash file to test. */
   var filePath = (function() {
     var min = 2,
@@ -606,7 +610,7 @@
       "    'weakSet': root.WeakSet ? new root.WeakSet : undefined",
       '  };',
       '',
-      "  ['" + typedArrays.join("', '") + "'].forEach(function(type) {",
+      "  ['" + arrayViews.join("', '") + "'].forEach(function(type) {",
       '    var Ctor = root[type]',
       '    object[type.toLowerCase()] = Ctor ? new Ctor(new ArrayBuffer(24)) : undefined;',
       '  });',
@@ -655,7 +659,7 @@
       "  'weakSet': root.WeakSet ? new root.WeakSet : undefined",
       '};',
       '',
-      "_.each(['" + typedArrays.join("', '") + "'], function(type) {",
+      "_.each(['" + arrayViews.join("', '") + "'], function(type) {",
       '  var Ctor = root[type];',
       '  object[type.toLowerCase()] = Ctor ? new Ctor(new ArrayBuffer(24)) : undefined;',
       '});',
@@ -2884,8 +2888,8 @@
         }
       });
 
-      lodashStable.each(typedArrays, function(type) {
+      lodashStable.each(arrayViews, function(type) {
-        QUnit.test('`_.' + methodName + '` should clone ' + type + ' arrays', function(assert) {
+        QUnit.test('`_.' + methodName + '` should clone ' + type + ' values', function(assert) {
           assert.expect(10);
 
           var Ctor = root[type];
@@ -2893,14 +2897,14 @@
           lodashStable.times(2, function(index) {
             if (Ctor) {
               var buffer = new ArrayBuffer(24),
-                  array = index ? new Ctor(buffer, 8, 1) : new Ctor(buffer),
+                  view = index ? new Ctor(buffer, 8, 1) : new Ctor(buffer),
-                  actual = func(array);
+                  actual = func(view);
 
-              assert.deepEqual(actual, array);
+              assert.deepEqual(actual, view);
-              assert.notStrictEqual(actual, array);
+              assert.notStrictEqual(actual, view);
-              assert.strictEqual(actual.buffer === array.buffer, !isDeep);
+              assert.strictEqual(actual.buffer === view.buffer, !isDeep);
-              assert.strictEqual(actual.byteOffset, array.byteOffset);
+              assert.strictEqual(actual.byteOffset, view.byteOffset);
-              assert.strictEqual(actual.length, array.length);
+              assert.strictEqual(actual.length, view.length);
             }
             else {
               skipAssert(assert, 5);
@@ -9210,6 +9214,29 @@
       }
     });
 
+    QUnit.test('should compare array views', function(assert) {
+      assert.expect(1);
+
+      var pairs = lodashStable.map(arrayViews, function(type, index) {
+        var otherType = arrayViews[(index + 1) % arrayViews.length],
+            CtorA = root[type] || function(n) { this.n = n; },
+            CtorB = root[otherType] || function(n) { this.n = n; },
+            bufferA = root[type] ? new ArrayBuffer(8) : 8,
+            bufferB = root[otherType] ? new ArrayBuffer(8) : 8,
+            bufferC = root[otherType] ? new ArrayBuffer(16) : 16;
+
+        return [new CtorA(bufferA), new CtorA(bufferA), new CtorB(bufferB), new CtorB(bufferC)];
+      });
+
+      var expected = lodashStable.map(pairs, lodashStable.constant([true, false, false]));
+
+      var actual = lodashStable.map(pairs, function(pair) {
+        return [_.isEqual(pair[0], pair[1]), _.isEqual(pair[0], pair[2]), _.isEqual(pair[2], pair[3])];
+      });
+
+      assert.deepEqual(actual, expected);
+    });
+
     QUnit.test('should compare date objects', function(assert) {
       assert.expect(4);
 
@@ -9390,29 +9417,6 @@
       }
     });
 
-    QUnit.test('should compare typed arrays', function(assert) {
-      assert.expect(1);
-
-      var pairs = lodashStable.map(typedArrays, function(type, index) {
-        var otherType = typedArrays[(index + 1) % typedArrays.length],
-            CtorA = root[type] || function(n) { this.n = n; },
-            CtorB = root[otherType] || function(n) { this.n = n; },
-            bufferA = root[type] ? new ArrayBuffer(8) : 8,
-            bufferB = root[otherType] ? new ArrayBuffer(8) : 8,
-            bufferC = root[otherType] ? new ArrayBuffer(16) : 16;
-
-        return [new CtorA(bufferA), new CtorA(bufferA), new CtorB(bufferB), new CtorB(bufferC)];
-      });
-
-      var expected = lodashStable.map(pairs, lodashStable.constant([true, false, false]));
-
-      var actual = lodashStable.map(pairs, function(pair) {
-        return [_.isEqual(pair[0], pair[1]), _.isEqual(pair[0], pair[2]), _.isEqual(pair[2], pair[3])];
-      });
-
-      assert.deepEqual(actual, expected);
-    });
-
     QUnit.test('should work as an iteratee for `_.every`', function(assert) {
       assert.expect(1);
 
@@ -9825,14 +9829,14 @@
       assert.strictEqual(_.isFunction(generator), typeof generator == 'function');
     });
 
-    QUnit.test('should return `true` for typed array constructors', function(assert) {
+    QUnit.test('should return `true` for array view constructors', function(assert) {
       assert.expect(1);
 
-      var expected = lodashStable.map(typedArrays, function(type) {
+      var expected = lodashStable.map(arrayViews, function(type) {
         return objToString.call(root[type]) == funcTag;
       });
 
-      var actual = lodashStable.map(typedArrays, function(type) {
+      var actual = lodashStable.map(arrayViews, function(type) {
         return _.isFunction(root[type]);
       });