Ensure that Set#keys is the same object as Set#values.

Per https://people.mozilla.org/~jorendorff/es6-draft.html#sec-set.prototype.keys
paulmillr · Nov 20, 2014 · c955ed7 · c955ed7
1 parent 151113e
commit c955ed7
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Showing 2 changed files with 9 additions and 6 deletions.
diff --git a/es6-shim.js b/es6-shim.js
@@ -1943,11 +1943,6 @@
             return this['[[SetData]]'].clear();
           },
 
-          keys: function () {
-            ensureMap(this);
-            return this['[[SetData]]'].keys();
-          },
-
           values: function () {
             ensureMap(this);
             return this['[[SetData]]'].values();
@@ -1967,6 +1962,7 @@
             });
           }
         });
+        defineProperty(SetShim, 'keys', SetShim.values, true);
         addIterator(SetShim.prototype, function () { return this.values(); });
 
         return SetShim;
@@ -2004,6 +2000,9 @@
         globals.Set = collectionShims.Set;
       }
     }
+    if (globals.Set.prototype.keys !== globals.Set.prototype.values) {
+      defineProperty(globals.Set.prototype, 'keys', globals.Set.prototype.values, true);
+    }
     // Shim incomplete iterator implementations.
     addIterator(Object.getPrototypeOf((new globals.Map()).keys()));
     addIterator(Object.getPrototypeOf((new globals.Set()).keys()));

diff --git a/test/collections.js b/test/collections.js
@@ -461,10 +461,14 @@ describe('Collections', function () {
       expect(typeof Set).to.equal('function');
     });
 
-    it('should have the right arity', function () {
+    it('has the right arity', function () {
       expect(Set.length).to.equal(1);
     });
 
+    it('has #keys which is the same object as #values', function () {
+      expect(Set.prototype.keys).to.equal(Set.prototype.values);
+    });
+
     it('returns the set from #add() for chaining', function () {
       expect(set.add({})).to.equal(set);
     });