Merge pull request #148 from rubycdp/fix-145

Fix 145

Author: route

lib/capybara/cuprite/javascripts/index.js

@@ -41,7 +41,7 @@ class Cuprite {
   parents(node) {
     let nodes = [];
     let parent = node.parentNode;
-    while (parent != document) {
+    while (parent != document && parent !== null) {
       nodes.push(parent);
       parent = parent.parentNode;
     }
@@ -97,7 +97,7 @@ class Cuprite {
   path(node) {
     let nodes = [node];
     let parent = node.parentNode;
-    while (parent !== document) {
+    while (parent !== document && parent !== null) {
       nodes.unshift(parent);
       parent = parent.parentNode;
     }