added the new button for restarting the practice proctored exam.

 This is only visible in the error case scenario

edx_proctoring/api.py

@@ -213,16 +213,22 @@ def create_exam_attempt(exam_id, user_id, taking_as_proctored=False):
     one exam_attempt per user per exam. Multiple attempts by user will be archived
     in a separate table
     """
-    if ProctoredExamStudentAttempt.objects.get_exam_attempt(exam_id, user_id):
-        err_msg = (
-            'Cannot create new exam attempt for exam_id = {exam_id} and '
-            'user_id = {user_id} because it already exists!'
-        ).format(exam_id=exam_id, user_id=user_id)
-
-        raise StudentExamAttemptAlreadyExistsException(err_msg)
-
     # for now the student is allowed the exam default
+
     exam = get_exam_by_id(exam_id)
+    existing_attempt = ProctoredExamStudentAttempt.objects.get_exam_attempt(exam_id, user_id)
+    if existing_attempt:
+        if existing_attempt.is_sample_attempt:
+            # Archive the existing attempt by deleting it.
+            existing_attempt.delete_exam_attempt()
+        else:
+            err_msg = (
+                'Cannot create new exam attempt for exam_id = {exam_id} and '
+                'user_id = {user_id} because it already exists!'
+            ).format(exam_id=exam_id, user_id=user_id)
+
+            raise StudentExamAttemptAlreadyExistsException(err_msg)
+
     allowed_time_limit_mins = exam['time_limit_mins']
 
     # add in the allowed additional time
@@ -506,9 +512,13 @@ def get_student_view(user_id, course_id, content_id,
         'credit_state' in context and
         context['credit_state']
     )
+
     if check_mode:
+        # Return None (show exam content) for non verified users unless it's a practice exam
+        # where both honor and verified users are shown the proctoring screen.
         if context['credit_state']['enrollment_mode'] != 'verified':
-            return None
+            if not (context['is_practice_exam'] and context['credit_state']['enrollment_mode'] == 'honor'):
+                return None
 
     student_view_template = None
 
@@ -602,6 +612,7 @@ def get_student_view(user_id, course_id, content_id,
             'total_time': total_time,
             'exam_id': exam_id,
             'progress_page_url': progress_page_url,
+            'is_sample_attempt': attempt['is_sample_attempt'] if attempt else False,
             'enter_exam_endpoint': reverse('edx_proctoring.proctored_exam.attempt.collection'),
             'exam_started_poll_url': reverse(
                 'edx_proctoring.proctored_exam.attempt',

edx_proctoring/templates/proctoring/rerun_practice_attempt.html

+{% load i18n %}
+<p>{% blocktrans %}   You can also retake the exam.  {% endblocktrans %}</p>
+<button type="button" name="submit-proctored-exam" class="start-timed-exam" data-ajax-url="{{enter_exam_endpoint}}" data-exam-id="{{exam_id}}" data-attempt-proctored=true data-start-immediately=false >
+    {% blocktrans %}
+      Re-run the Exam
+    {% endblocktrans %}
+</button>
+<script type="text/javascript">
+  $('.start-timed-exam').click(
+    function(event) {
+      var action_url = $(this).data('ajax-url');
+      var exam_id = $(this).data('exam-id');
+      var attempt_proctored = $(this).data('attempt-proctored');
+      var start_immediately = $(this).data('start-immediately');
+      if (typeof action_url === "undefined" ) {
+        return false;
+      }
+      $.post(
+        action_url,
+        {
+          "exam_id": exam_id,
+          "attempt_proctored": attempt_proctored,
+          "start_clock": start_immediately
+        },
+        function(data) {
+          // reload the page, because we've unlocked it
+          location.reload();
+        }
+      );
+    }
+  );
+</script>
\ No newline at end of file

edx_proctoring/templates/proctoring/seq_proctored_exam_error.html

@@ -4,3 +4,6 @@
         {% trans "Your exam has been marked as failed due to an error." %}
     </div>
 </div>
+{% if is_sample_attempt %}
+    {% include 'proctoring/rerun_practice_attempt.html' %}
+{% endif %}
\ No newline at end of file

edx_proctoring/tests/test_api.py

@@ -169,6 +169,7 @@ class ProctoredExamApiTests(LoggedInTestCase):
             user_id=self.user_id,
             external_id=self.external_id,
             started_at=started_at if started_at else datetime.now(pytz.UTC),
+            is_sample_attempt=True,
             status=ProctoredExamStudentAttemptStatus.started,
             allowed_time_limit_mins=10
         )
@@ -368,6 +369,14 @@ class ProctoredExamApiTests(LoggedInTestCase):
         with self.assertRaises(StudentExamAttemptAlreadyExistsException):
             create_exam_attempt(proctored_exam_student_attempt.proctored_exam.id, self.user_id)
 
+    def test_recreate_a_practice_exam_attempt(self):  # pylint: disable=invalid-name
+        """
+        Taking the practice exam several times should not cause an exception.
+        """
+        practice_exam_student_attempt = self._create_started_practice_exam_attempt()
+        new_attempt_id = create_exam_attempt(practice_exam_student_attempt.proctored_exam.id, self.user_id)
+        self.assertGreater(practice_exam_student_attempt, new_attempt_id, "New attempt not created.")
+
     def test_get_exam_attempt(self):
         """
         Test to get the existing exam attempt.
@@ -560,9 +569,30 @@ class ProctoredExamApiTests(LoggedInTestCase):
         self.assertIn('data-exam-id="%d"' % self.proctored_exam_id, rendered_response)
         self.assertIn(self.start_an_exam_msg % self.exam_name, rendered_response)
 
-    def test_get_honot_view(self):
+    def test_get_honor_view_with_practice_exam(self):  # pylint: disable=invalid-name
         """
-        Test for get_student_view promting when the student is enrolled in non-verified
+        Test for get_student_view prompting when the student is enrolled in non-verified
+        track for a practice exam, this should return not None
+        """
+        rendered_response = get_student_view(
+            user_id=self.user_id,
+            course_id=self.course_id,
+            content_id=self.content_id,
+            context={
+                'is_proctored': True,
+                'display_name': self.exam_name,
+                'default_time_limit_mins': 90,
+                'credit_state': {
+                    'enrollment_mode': 'honor'
+                },
+                'is_practice_exam': True
+            }
+        )
+        self.assertIsNotNone(rendered_response)
+
+    def test_get_honor_view(self):
+        """
+        Test for get_student_view prompting when the student is enrolled in non-verified
         track, this should return None
         """
         rendered_response = get_student_view(
@@ -575,7 +605,8 @@ class ProctoredExamApiTests(LoggedInTestCase):
                 'default_time_limit_mins': 90,
                 'credit_state': {
                     'enrollment_mode': 'honor'
-                }
+                },
+                'is_practice_exam': False
             }
         )
         self.assertIsNone(rendered_response)