Handle null nextDescription in describeElement (#1378)

* Handle null nextDescription in describeElement

Co-authored-by: Lucas Halfpenny <lucashalfpenny@gmail.com>

* Add a regression test for genElement handling elements with no tagName

Co-authored-by: Lucas Halfpenny <lucashalfpenny@gmail.com>

* lint fix

---------

Co-authored-by: Lucas Halfpenny <lucashalfpenny@gmail.com>
Co-authored-by: Walt Jones <walt.jones@rollbar.com>

Author: 3 people

src/browser/domUtility.js

@@ -34,7 +34,7 @@ function treeToArray(elem) {
   var nextDescription;
   for (var height = 0; elem && height < MAX_HEIGHT; height++) {
     nextDescription = describeElement(elem);
-    if (nextDescription.tagName === 'html') {
+    if (!nextDescription || nextDescription.tagName === 'html') {
       break;
     }
     out.unshift(nextDescription);

test/browser.domUtility.test.ts

@@ -118,6 +118,11 @@ describe('treeToArray', function () {
     const arr = d.treeToArray(e1);
     expect(arr.length).to.eql(5);
   });
+  it('should handle elements without tag names', function () {
+    const e1 = genElement(null);
+    const arr = d.treeToArray(e1);
+    expect(arr).to.eql([]);
+  });
   it('should put the innermost element last', function () {
     const e1 = genElement('div', 'id1');
     const e2 = genElement('div', 'id2', 'a b');