Fix deepEqual on Safari 9 due to Safari enumeration bug.

test/unit/notify-path.html

@@ -19,6 +19,21 @@
 
 <script>
 
+// Safari 9 has a horrible bug related to array enumeration after defining
+// a non-enumerable property on it (we do for `.splices`); for now we work
+// around chai's deepEqual implementation that enumerates array keys using
+// `for in` in the specific case the bug causes an assert failure
+function arraysEqual(a, b) {
+  for (var i=0; i<a.length; i++) {
+    if (a[i] !== b[i]) {
+      throw new Error('expected ' + a + ' to equal ' + b);
+    }
+  }
+  if (a.length != b.length) {
+    throw new Error('expected ' + a + ' to equal ' + b);
+  }
+}
+
 suite('basic path bindings', function() {
 
   var el;
@@ -1303,7 +1318,7 @@
     };
     el.set('array.0', -1);
     // Verify array contents
-    assert.deepEqual(el.array, [-1, 99, 2, 3]);
+    arraysEqual(el.array, [-1, 99, 2, 3]);
   });
 
 });