PLAT-1198 Fix flaky navigation buttons test

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

@@ -115,8 +115,17 @@ class CoursewarePage(CoursePage):
         Arguments:
             sequential_position (int): position in sequential bar
         """
+        def is_at_new_position():
+            """
+            Returns whether the specified tab has become active. It is defensive
+            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
+
         sequential_position_css = '#sequence-list #tab_{0}'.format(sequential_position - 1)
         self.q(css=sequential_position_css).first.click()
+        EmptyPromise(is_at_new_position, "Position navigation fulfilled").fulfill()
 
     @property
     def sequential_position(self):

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

@@ -436,7 +436,6 @@ class CoursewareMultipleVerticalsTest(UniqueCourseTest, EventsTestMixin):
         self.courseware_page.visit()
         self.course_nav = CourseNavPage(self.browser)
 
-    @flaky  # TODO: fix this, see TNL-5762
     def test_navigation_buttons(self):
         # start in first section
         self.assert_navigation_state('Test Section 1', 'Test Subsection 1,1', 0, next_enabled=True, prev_enabled=False)