Merge pull request #2986 from colingm/native-data-view

Add nativeDataView check to isDataView

karma.conf-sauce.js

@@ -63,6 +63,7 @@ module.exports = function(config) {
     files: [
       'test/vendor/qunit-extras.js',
       'test/qunit-setup.js',
+      'test/overrides.js',
       'underscore-umd.js',
       'test/*.js'
     ],

karma.conf.js

@@ -15,6 +15,7 @@ module.exports = function(config) {
     // list of files / patterns to load in the browser
     files: [
       'test/qunit-setup.js',
+      'test/overrides.js',
       'underscore-umd.js',
       'test/*.js'
     ],

modules/_stringTagBug.js

@@ -4,7 +4,10 @@ import hasObjectTag from './_hasObjectTag.js';
 // In IE 10 - Edge 13, `DataView` has string tag `'[object Object]'`.
 // In IE 11, the most common among them, this problem also applies to
 // `Map`, `WeakMap` and `Set`.
-export var hasStringTagBug = (
-      supportsDataView && hasObjectTag(new DataView(new ArrayBuffer(8)))
+// Also, there are cases where an application can override the native
+// `DataView` object, in cases like that we can't use the constructor
+// safely and should just rely on alternate `DataView` checks
+export var hasDataViewBug = (
+      supportsDataView && (!/\[native code\]/.test(String(DataView)) || hasObjectTag(new DataView(new ArrayBuffer(8))))
     ),
     isIE11 = (typeof Map !== 'undefined' && hasObjectTag(new Map));

modules/isDataView.js

@@ -1,14 +1,16 @@
 import tagTester from './_tagTester.js';
 import isFunction from './isFunction.js';
 import isArrayBuffer from './isArrayBuffer.js';
-import { hasStringTagBug } from './_stringTagBug.js';
+import { hasDataViewBug } from './_stringTagBug.js';
 
 var isDataView = tagTester('DataView');
 
 // In IE 10 - Edge 13, we need a different heuristic
 // to determine whether an object is a `DataView`.
-function ie10IsDataView(obj) {
+// Also, in cases where the native `DataView` is
+// overriden we can't rely on the tag itself.
+function alternateIsDataView(obj) {
   return obj != null && isFunction(obj.getInt8) && isArrayBuffer(obj.buffer);
 }
 
-export default (hasStringTagBug ? ie10IsDataView : isDataView);
+export default (hasDataViewBug ? alternateIsDataView : isDataView);

modules/isEqual.js

@@ -3,7 +3,7 @@ import { toString, SymbolProto } from './_setup.js';
 import getByteLength from './_getByteLength.js';
 import isTypedArray from './isTypedArray.js';
 import isFunction from './isFunction.js';
-import { hasStringTagBug }  from './_stringTagBug.js';
+import { hasDataViewBug }  from './_stringTagBug.js';
 import isDataView from './isDataView.js';
 import keys from './keys.js';
 import has from './_has.js';
@@ -36,7 +36,7 @@ function deepEq(a, b, aStack, bStack) {
   var className = toString.call(a);
   if (className !== toString.call(b)) return false;
   // Work around a bug in IE 10 - Edge 13.
-  if (hasStringTagBug && className == '[object Object]' && isDataView(a)) {
+  if (hasDataViewBug && className == '[object Object]' && isDataView(a)) {
     if (!isDataView(b)) return false;
     className = tagDataView;
   }

test/index.html

@@ -9,6 +9,7 @@
   <div id="qunit"></div>
   <div id="exports" style="display: none"></div>
   <script src="vendor/qunit.js"></script>
+  <script src="overrides.js"></script>
   <script src="../underscore-umd.js"></script>
   <script src="qunit-setup.js"></script>
   <script src="collections.js"></script>

test/objects.js

@@ -5,6 +5,9 @@
 
   var testElement = typeof document === 'object' ? document.createElement('div') : void 0;
 
+  // Some browsers support typed arrays but not DataView and some applications could override DataView
+  var DataViewImpl = typeof NativeDataView !== 'undefined' ? NativeDataView : typeof DataView !== 'undefined' ? DataView : undefined;
+
   QUnit.test('keys', function(assert) {
     assert.deepEqual(_.keys({one: 1, two: 2}), ['one', 'two'], 'can extract the keys from an object');
     // the test above is not safe because it relies on for-in enumeration order
@@ -610,11 +613,11 @@
       assert.notOk(_.isEqual(view1, view2), 'same buffer with different offset is not equal');
 
       // Some older browsers support typed arrays but not DataView.
-      if (typeof DataView !== 'undefined') {
-        assert.ok(_.isEqual(new DataView(u8.buffer), new DataView(u8b.buffer)), 'Identical DataViews are equal');
-        assert.ok(_.isEqual(new DataView(u8.buffer), new DataView(i8.buffer)), 'Identical DataViews of different typed arrays are equal');
-        assert.notOk(_.isEqual(new DataView(u8.buffer), new DataView(u16.buffer)), 'Different DataViews with different length are not equal');
-        assert.notOk(_.isEqual(new DataView(u8.buffer), new DataView(u16one.buffer)), 'Different DataViews with different byte data are not equal');
+      if (DataViewImpl) {
+        assert.ok(_.isEqual(new DataViewImpl(u8.buffer), new DataViewImpl(u8b.buffer)), 'Identical DataViews are equal');
+        assert.ok(_.isEqual(new DataViewImpl(u8.buffer), new DataViewImpl(i8.buffer)), 'Identical DataViews of different typed arrays are equal');
+        assert.notOk(_.isEqual(new DataViewImpl(u8.buffer), new DataViewImpl(u16.buffer)), 'Different DataViews with different length are not equal');
+        assert.notOk(_.isEqual(new DataViewImpl(u8.buffer), new DataViewImpl(u16one.buffer)), 'Different DataViews with different byte data are not equal');
       }
     }
   });
@@ -931,8 +934,8 @@
         'a TypedArray': new Uint8Array(buffer)
       };
       // Some older browsers support typed arrays but not DataView.
-      if (typeof DataView !== 'undefined') {
-        checkValues['a DataView'] = new DataView(buffer);
+      if (DataViewImpl) {
+        checkValues['a DataView'] = new DataViewImpl(buffer);
       }
       var types = ['an ArrayBuffer', 'a DataView', 'a TypedArray'];
       _.each(types, function(type) {

test/overrides.js

@@ -0,0 +1,12 @@
+(function() {
+  function overrideDataView() {
+    NativeDataView = DataView;
+    DataView = {};
+  }
+
+  // Only override browser functions roughly 1/3rd of the time
+  var runOverrides = Math.floor(Math.random() * 3) === 0;
+  if (runOverrides) {
+    overrideDataView();
+  }
+})();

underscore-node-f.cjs

@@ -143,20 +143,25 @@ var hasObjectTag = tagTester('Object');
 // In IE 10 - Edge 13, `DataView` has string tag `'[object Object]'`.
 // In IE 11, the most common among them, this problem also applies to
 // `Map`, `WeakMap` and `Set`.
-var hasStringTagBug = (
-      supportsDataView && hasObjectTag(new DataView(new ArrayBuffer(8)))
+// Also, there are cases where an application can override the native
+// `DataView` object, in cases like that we can't use the constructor
+// safely and should just rely on alternate `DataView` checks
+var hasDataViewBug = (
+      supportsDataView && (!/\[native code\]/.test(String(DataView)) || hasObjectTag(new DataView(new ArrayBuffer(8))))
     ),
     isIE11 = (typeof Map !== 'undefined' && hasObjectTag(new Map));
 
 var isDataView = tagTester('DataView');
 
 // In IE 10 - Edge 13, we need a different heuristic
 // to determine whether an object is a `DataView`.
-function ie10IsDataView(obj) {
+// Also, in cases where the native `DataView` is
+// overriden we can't rely on the tag itself.
+function alternateIsDataView(obj) {
   return obj != null && isFunction$1(obj.getInt8) && isArrayBuffer(obj.buffer);
 }
 
-var isDataView$1 = (hasStringTagBug ? ie10IsDataView : isDataView);
+var isDataView$1 = (hasDataViewBug ? alternateIsDataView : isDataView);
 
 // Is a given value an array?
 // Delegates to ECMA5's native `Array.isArray`.
@@ -369,7 +374,7 @@ function deepEq(a, b, aStack, bStack) {
   var className = toString.call(a);
   if (className !== toString.call(b)) return false;
   // Work around a bug in IE 10 - Edge 13.
-  if (hasStringTagBug && className == '[object Object]' && isDataView$1(a)) {
+  if (hasDataViewBug && className == '[object Object]' && isDataView$1(a)) {
     if (!isDataView$1(b)) return false;
     className = tagDataView;
   }