PLAT-1198 Reduce risk of losing navigation events

common/test/acceptance/pages/lms/courseware.py

@@ -131,7 +131,10 @@ class CoursewarePage(CoursePage):
             against the case where the page is still being loaded.
             """
             active_tab = self._active_sequence_tab
-            return active_tab and int(active_tab.attrs('data-element')[0]) == sequential_position
+            try:
+                return active_tab and int(active_tab.attrs('data-element')[0]) == sequential_position
+            except IndexError:
+                return False
 
         sequential_position_css = '#sequence-list #tab_{0}'.format(sequential_position - 1)
         self.q(css=sequential_position_css).first.click()
@@ -181,7 +184,10 @@ class CoursewarePage(CoursePage):
             against the case where the page is still being loaded.
             """
             active_tab = self._active_sequence_tab
-            return active_tab and previous_tab_id != active_tab.attrs('data-id')[0]
+            try:
+                return active_tab and previous_tab_id != active_tab.attrs('data-id')[0]
+            except IndexError:
+                return False
 
         self.q(
             css='.{} > .sequence-nav-button.{}'.format(top_or_bottom_class, next_or_previous_class)

common/test/acceptance/tests/lms/test_lms_courseware.py

@@ -5,7 +5,6 @@ End-to-end tests for the LMS.
 
 import json
 from datetime import datetime, timedelta
-from unittest import skip
 
 import ddt
 from flaky import flaky
@@ -441,7 +440,7 @@ class CoursewareMultipleVerticalsTest(CoursewareMultipleVerticalsTestBase):
     Test courseware with multiple verticals
     """
 
-    @skip('Disable temporarily to get course bookmarks out')
+    @flaky  # PLAT-1198; should be fixed, but verify that failures stop before removing
     def test_navigation_buttons(self):
         self.courseware_page.visit()