Temporarily disable capa name masking

There is a bug I need to fix when a student re-visits a problem that they
had solved previously without masking enabled, their old state does not
load correclty.

It's simplest to turn off masking now, and re-enable it with the whole fix.

The change here is a small deletion to remove the masking=True logic, and more
lengthy changes to adjust the tests.

common/lib/capa/capa/responsetypes.py

@@ -780,19 +780,7 @@ class MultipleChoiceResponse(LoncapaResponse):
         for response in self.xml.xpath("choicegroup"):
             # Is Masking enabled? -- check for shuffle or answer-pool features
             ans_str = response.get("answer-pool")
-            if response.get("shuffle") == "true" or (ans_str is not None and ans_str != "0"):
-                self._has_mask = True  # pylint: disable=W0201
-                self._mask_dict = {}   # pylint: disable=W0201
-                # We do not want the random mask names to be the same
-                # for all responses in a problem (sharing the one seed),
-                # like mask_2 in view-source turns out to always be the correct choice.
-                # But it must be repeatable and a function of the seed.
-                # Therefore we add the _1 number from the .id to the seed.
-                seed_delta = int(self.id[self.id.rindex("_") + 1:])
-                rng = random.Random(self.context["seed"] + seed_delta)
-                # e.g. mask_ids = [3, 1, 0, 2]
-                mask_ids = range(len(response))
-                rng.shuffle(mask_ids)
+            # Masking (self._has_mask) is off, to be re-enabled with a future PR.
             rtype = response.get('type')
             if rtype not in ["MultipleChoice"]:
                 # force choicegroup to be MultipleChoice if not valid
@@ -853,11 +841,11 @@ class MultipleChoiceResponse(LoncapaResponse):
         """
         Returns a list of the choice names in the order displayed to the user,
         using the regular (non-masked) names.
-        Fails with LoncapaProblemError if called on a response that is not masking.
         """
+        # With masking disabled, this computation remains interesting to see
+        # the displayed order, even though there is no unmasking.
         choices = self.xml.xpath('choicegroup/choice')
-        # We let the unmask_name() raise the error for us if this response is not masking.
-        return [self.unmask_name(choice.get("name")) for choice in choices]
+        return [choice.get("name") for choice in choices]
 
     def do_shuffle(self, tree, problem):
         """

common/lib/capa/capa/tests/test_answer_pool.py

@@ -59,7 +59,7 @@ class CapaAnswerPoolTest(unittest.TestCase):
         self.assertEqual(the_html, problem.get_html(), 'should be able to call get_html() twice')
         # Check about masking
         response = problem.responders.values()[0]
-        self.assertTrue(response.has_mask())
+        self.assertFalse(response.has_mask())
         self.assertTrue(response.has_answerpool())
         self.assertEqual(response.unmask_order(), ['choice_3', 'choice_5', 'choice_1', 'choice_4'])
 
@@ -71,7 +71,7 @@ class CapaAnswerPoolTest(unittest.TestCase):
         self.assertRegexpMatches(the_html, r"<div>\{.*'1_solution_1'.*\}</div>")
         # Check about masking
         response = problem.responders.values()[0]
-        self.assertTrue(hasattr(response, 'has_mask'))
+        self.assertFalse(response.has_mask())
         self.assertTrue(hasattr(response, 'has_answerpool'))
         self.assertEqual(response.unmask_order(), ['choice_0', 'choice_4', 'choice_3', 'choice_2'])
 
@@ -280,7 +280,7 @@ class CapaAnswerPoolTest(unittest.TestCase):
         self.assertRegexpMatches(the_html, r"<div>.*\[.*'correct-2'.*'wrong-1'.*'wrong-2'.*.*'wrong-3'.*'wrong-4'.*\].*</div>")
         self.assertRegexpMatches(the_html, r"<div>\{.*'1_solution_2'.*\}</div>")
         response = problem.responders.values()[0]
-        self.assertTrue(response.has_mask())
+        self.assertFalse(response.has_mask())
         self.assertEqual(response.unmask_order(), ['choice_5', 'choice_0', 'choice_1', 'choice_3', 'choice_4'])
 
     def test_answer_pool_2_multiplechoiceresponses_seed1(self):

common/lib/capa/capa/tests/test_shuffle.py

@@ -34,7 +34,7 @@ class CapaShuffleTest(unittest.TestCase):
         self.assertRegexpMatches(the_html, r"<div>.*\[.*'Banana'.*'Apple'.*'Chocolate'.*'Donut'.*\].*</div>")
         # Check that choice name masking is enabled and that unmasking works
         response = problem.responders.values()[0]
-        self.assertTrue(response.has_mask())
+        self.assertFalse(response.has_mask())
         self.assertEqual(response.unmask_order(), ['choice_1', 'choice_0', 'choice_2', 'choice_3'])
         self.assertEqual(the_html, problem.get_html(), 'should be able to call get_html() twice')
 
@@ -55,7 +55,7 @@ class CapaShuffleTest(unittest.TestCase):
         # B A C D
         # Check that the custom name= names come through
         response = problem.responders.values()[0]
-        self.assertTrue(response.has_mask())
+        self.assertFalse(response.has_mask())
         self.assertTrue(response.has_shuffle())
         self.assertEqual(response.unmask_order(), ['choice_0', 'choice_aaa', 'choice_1', 'choice_ddd'])
 
@@ -90,10 +90,9 @@ class CapaShuffleTest(unittest.TestCase):
         the_html = problem.get_html()
         self.assertRegexpMatches(the_html, r"<div>.*\[.*'Apple'.*\].*</div>")
         response = problem.responders.values()[0]
-        self.assertTrue(response.has_mask())
+        self.assertFalse(response.has_mask())
         self.assertTrue(response.has_shuffle())
         self.assertEqual(response.unmask_order(), ['choice_0'])
-        self.assertEqual(response.unmask_name('mask_0'), 'choice_0')
 
     def test_shuffle_6_choices(self):
         xml_str = textwrap.dedent("""
@@ -279,9 +278,8 @@ class CapaShuffleTest(unittest.TestCase):
                                        r"<div>.*\[.*'C'.*'A'.*'D'.*'B'.*\].*</div>")
         # Look at the responses in their authored order
         responses = sorted(problem.responders.values(), key=lambda resp: int(resp.id[resp.id.rindex('_') + 1:]))
-        self.assertTrue(responses[0].has_mask())
+        self.assertFalse(responses[0].has_mask())
         self.assertTrue(responses[0].has_shuffle())
-        self.assertTrue(hasattr(responses[1], 'has_mask'))
         self.assertTrue(responses[1].has_shuffle())
         self.assertEqual(responses[0].unmask_order(), ['choice_1', 'choice_0', 'choice_2', 'choice_3'])
         self.assertEqual(responses[1].unmask_order(), ['choice_2', 'choice_0', 'choice_3', 'choice_1'])

common/lib/capa/capa/tests/test_targeted_feedback.py

@@ -586,7 +586,7 @@ class CapaTargetedFeedbackTest(unittest.TestCase):
     def test_targeted_feedback_multiple_answer_2(self):
         problem = new_loncapa_problem(load_fixture('targeted_feedback_multiple.xml'))
         problem.done = True
-        problem.student_answers = {'1_2_1': 'choice_0', '1_3_1': 'mask_1'}  # Q1 wrong, Q2 correct
+        problem.student_answers = {'1_2_1': 'choice_0', '1_3_1': 'choice_2'}  # Q1 wrong, Q2 correct
         the_html = problem.get_html()
         without_new_lines = the_html.replace("\n", "")
         # Q1 has feedback1 and Q2 has feedbackC

common/lib/xmodule/xmodule/tests/test_capa_module.py

@@ -1454,17 +1454,17 @@ class CapaModuleTest(unittest.TestCase):
         """
         module = CapaFactory.create(xml=self.common_shuffle_xml)
         with patch.object(module.runtime, 'track_function') as mock_track_function:
-            get_request_dict = {CapaFactory.input_key(): 'mask_1'}  # the correct choice
+            get_request_dict = {CapaFactory.input_key(): 'choice_3'}  # the correct choice
             module.check_problem(get_request_dict)
             mock_call = mock_track_function.mock_calls[0]
             event_info = mock_call[1][1]
-            # 'answers' key modified to use unmasked name
             self.assertEqual(event_info['answers'][CapaFactory.answer_key()], 'choice_3')
             # 'permutation' key added to record how problem was shown
             self.assertEquals(event_info['permutation'][CapaFactory.answer_key()],
                               ('shuffle', ['choice_3', 'choice_1', 'choice_2', 'choice_0']))
             self.assertEquals(event_info['success'], 'correct')
 
+    @unittest.skip("masking temporarily disabled")
     def test_save_unmask(self):
         """On problem save, unmasked data should appear on track_function."""
         module = CapaFactory.create(xml=self.common_shuffle_xml)
@@ -1476,6 +1476,7 @@ class CapaModuleTest(unittest.TestCase):
             self.assertEquals(event_info['answers'][CapaFactory.answer_key()], 'choice_2')
             self.assertIsNotNone(event_info['permutation'][CapaFactory.answer_key()])
 
+    @unittest.skip("masking temporarily disabled")
     def test_reset_unmask(self):
         """On problem reset, unmask names should appear track_function."""
         module = CapaFactory.create(xml=self.common_shuffle_xml)
@@ -1490,6 +1491,7 @@ class CapaModuleTest(unittest.TestCase):
             self.assertEquals(event_info['old_state']['student_answers'][CapaFactory.answer_key()], 'choice_2')
             self.assertIsNotNone(event_info['permutation'][CapaFactory.answer_key()])
 
+    @unittest.skip("masking temporarily disabled")
     def test_rescore_unmask(self):
         """On problem rescore, unmasked names should appear on track_function."""
         module = CapaFactory.create(xml=self.common_shuffle_xml)
@@ -1520,12 +1522,10 @@ class CapaModuleTest(unittest.TestCase):
         """)
         module = CapaFactory.create(xml=xml)
         with patch.object(module.runtime, 'track_function') as mock_track_function:
-            get_request_dict = {CapaFactory.input_key(): 'mask_0'}
+            get_request_dict = {CapaFactory.input_key(): 'choice_2'}  # mask_X form when masking enabled
             module.check_problem(get_request_dict)
             mock_call = mock_track_function.mock_calls[0]
             event_info = mock_call[1][1]
-            print event_info
-            # 'answers' key modified to use unmasked name
             self.assertEqual(event_info['answers'][CapaFactory.answer_key()], 'choice_2')
             # 'permutation' key added to record how problem was shown
             self.assertEquals(event_info['permutation'][CapaFactory.answer_key()],