From a9f71bd1ef3f87d97aada7ea049343254dbdb5bd Mon Sep 17 00:00:00 2001
From: Kevin Schaaf <kschaaf@google.com>
Date: Wed, 10 Jan 2018 11:34:48 -0800
Subject: [PATCH] Ensure path notifications from templatized instances don't
 throw. Fixes #3422

---
 lib/utils/templatize.html |  9 +++++++++
 test/unit/templatize.html | 11 +++++++++++
 2 files changed, 20 insertions(+)

diff --git a/lib/utils/templatize.html b/lib/utils/templatize.html
index dbd69d4505..d8a2ac296c 100644
--- a/lib/utils/templatize.html
+++ b/lib/utils/templatize.html
@@ -225,6 +225,15 @@
         }
         return model;
       }
+
+      /**
+       * Stub of HTMLElement's `dispatchEvent`, so that effects that may
+       * dispatch events safely no-op.
+       *
+       * @param event {Event} Event to dispatch
+       */
+       dispatchEvent(event) {
+      }
     }
 
     /** @type {!DataTemplate} */
diff --git a/test/unit/templatize.html b/test/unit/templatize.html
index b0cc8af595..7a405c4792 100644
--- a/test/unit/templatize.html
+++ b/test/unit/templatize.html
@@ -355,6 +355,17 @@
       assert.equal(div.textContent, 'text');
     });
  
+    test('notifies path data changes', function() {
+      const template = document.getElementById('standalone').cloneNode(true);
+      const Template = Polymer.Templatize.templatize(template);
+      const inst = new Template();
+      const div = inst.root.firstElementChild;
+      inst.setProperties({prop: {foo: true}});
+      assert.equal(div.prop.foo, true);
+      inst.set('prop.foo', false);
+      assert.equal(div.prop.foo, false);
+    });
+ 
   });
 
 </script>