Merge pull request #1473 from Polymer/0.8-behaviors-first

use `hasOwnProperty` to avoid overwriting prototype methods when mixing in behaviors (+test)
Polymer · Apr 30, 2015 · bcd2923 · bcd2923
2 parents db6ebd5 + 260dfdd
commit bcd2923
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Showing 4 changed files with 33 additions and 15 deletions.
diff --git a/src/micro/behaviors.html b/src/micro/behaviors.html
@@ -43,17 +43,13 @@
     behaviors: [],
 
     _prepBehaviors: function() {
-      this._flattenBehaviors();
-      this._prepBehavior(this);
-      this.behaviors.forEach(function(b) {
-        this._mixinBehavior(b);
-        this._prepBehavior(b);
-      }, this);
+      this.behaviors = this._flattenBehaviorsList(this.behaviors);
+      this._prepAllBehaviors();
     },
 
-    _flattenBehaviors: function() {
+    _flattenBehaviorsList: function(behaviors) {
       var flat = [];
-      this.behaviors.forEach(function(b) {
+      behaviors.forEach(function(b) {
         if (!b) {
           console.warn('Polymer: undefined behavior in [' + this.is + ']');
         } else if (b instanceof Array) {
@@ -62,7 +58,15 @@
           flat.push(b);
         }
       }, this);
-      this.behaviors = flat;
+      return flat;
+    },
+
+    _prepAllBehaviors: function() {
+      this.behaviors.forEach(function(b) {
+        this._mixinBehavior(b);
+        this._prepBehavior(b);
+      }, this);
+      this._prepBehavior(this);
     },
 
     _mixinBehavior: function(b) {
@@ -82,7 +86,9 @@
           case 'ready':
             break;
           default:
-            this.copyOwnProperty(n, b, this);
+            if (!this.hasOwnProperty(n)) {
+              this.copyOwnProperty(n, b, this);
+            }
             break;
         }
       }, this);

diff --git a/test/runner.html b/test/runner.html
@@ -20,6 +20,7 @@
       'unit/micro.html',
       'unit/attributes.html',
       'unit/async.html',
+      'unit/behaviors.html',
       'unit/template.html',
       'unit/ready.html',
       'unit/ready-shadow.html',
@@ -40,8 +41,7 @@
       'unit/x-style.html',
       'unit/dynamic-import.html',
       'unit/x-repeat.html',
-      'unit/x-if.html',
-      'unit/behaviors.html'
+      'unit/x-if.html'
     ]);
   </script>
 </body>

diff --git a/test/unit/behaviors-elements.html b/test/unit/behaviors-elements.html
@@ -40,6 +40,9 @@
 
     _changeHandler: function(e) {
       this.__change = e.detail.value;
+    },
+
+    _toOverride: function() {
     }
 
   };
@@ -71,9 +74,11 @@
 
     ready: function() {
       this.__readyB = true;
-    }
+    },
+
+    _toOverride: function() {}
 
-  }
+  };
 
 </script>
 
@@ -97,6 +102,8 @@
 
   <script>
 
+    Polymer._toOverride = function() {};
+
     Polymer({
 
       behaviors: [
@@ -117,7 +124,9 @@
 
       _fooChanged: function(foo) {
         this.__foo = foo;
-      }
+      },
+
+     _toOverride: Polymer._toOverride
 
     });
 

diff --git a/test/unit/behaviors.html b/test/unit/behaviors.html
@@ -103,6 +103,9 @@
     assert.equal(typeof el._setHasOptionsB, 'function');
   });
 
+  test('behavior overrides are last', function() {
+    assert.equal(el._toOverride, Polymer._toOverride);
+  });
 });
 
 </script>