Added more stubbed methods for dummy event object.

Author: kirk-sayre-work

boilerplate.js

@@ -50,6 +50,12 @@ const dummyEvent = {
  key: 97, // "a"
 
  stopPropagation: function() {},
+ preventDefault: function() {},
+ composedPath: function() {
+ return {
+ includes: function() { return false; },
+ };
+ },
 };
 
 // Handle Blobs. All Blob methods in the real Blob class for dumping