refactor: removes deprecated calls to runtime.xqueue from code and tests

* Uses the XQueueService object from the ModuleSystem in the LoncapaSystem
  instead of the dict of xqueue-related values.
* Adds a StubXQueueService for testing.

common/lib/capa/capa/inputtypes.py

@@ -994,9 +994,9 @@ class MatlabInput(CodeInput):
         response = data['submission']
 
         # construct xqueue headers
-        qinterface = self.capa_system.xqueue['interface']
+        qinterface = self.capa_system.xqueue.interface
         qtime = datetime.utcnow().strftime(xqueue_interface.dateformat)
-        callback_url = self.capa_system.xqueue['construct_callback']('ungraded_response')
+        callback_url = self.capa_system.xqueue.construct_callback('ungraded_response')
         anonymous_student_id = self.capa_system.anonymous_student_id
         # TODO: Why is this using self.capa_system.seed when we have self.seed???
         queuekey = xqueue_interface.make_hashkey(str(self.capa_system.seed) + qtime +

common/lib/capa/capa/responsetypes.py

@@ -2586,14 +2586,14 @@ class CodeResponse(LoncapaResponse):
     """
     Grade student code using an external queueing server, called 'xqueue'.
 
-    Expects 'xqueue' dict in LoncapaSystem with the following keys that are
+    Expects 'xqueue' dict in LoncapaSystem with the following properties that are
     needed by CodeResponse::
 
-        capa_system.xqueue = {
-            'interface': XQueueInterface object.
-            'construct_callback': Per-StudentModule callback URL constructor,
+        capa_system.xqueue = object with properties:
+            interface: XQueueInterface object.
+            construct_callback: Per-StudentModule callback URL constructor,
                 defaults to using 'score_update' as the correct dispatch (function).
-            'default_queuename': Default queue name to submit request (string).
+            default_queuename: Default queue name to submit request (string).
         }
 
     External requests are only submitted for student submission grading, not
@@ -2623,7 +2623,7 @@ class CodeResponse(LoncapaResponse):
 
         # We do not support xqueue within Studio.
         if self.capa_system.xqueue is not None:
-            default_queuename = self.capa_system.xqueue['default_queuename']
+            default_queuename = self.capa_system.xqueue.default_queuename
         else:
             default_queuename = None
         self.queue_name = xml.get('queuename', default_queuename)
@@ -2684,7 +2684,7 @@ class CodeResponse(LoncapaResponse):
         # Prepare xqueue request
         #------------------------------------------------------------
 
-        qinterface = self.capa_system.xqueue['interface']
+        qinterface = self.capa_system.xqueue.interface
         qtime = datetime.strftime(datetime.now(UTC), xqueue_interface.dateformat)
 
         anonymous_student_id = self.capa_system.anonymous_student_id
@@ -2693,7 +2693,7 @@ class CodeResponse(LoncapaResponse):
         queuekey = xqueue_interface.make_hashkey(
             str(self.capa_system.seed) + qtime + anonymous_student_id + self.answer_id
         )
-        callback_url = self.capa_system.xqueue['construct_callback']()
+        callback_url = self.capa_system.xqueue.construct_callback()
         xheader = xqueue_interface.make_xheader(
             lms_callback_url=callback_url,
             lms_key=queuekey,

common/lib/capa/capa/tests/helpers.py

@@ -44,12 +44,19 @@ def tst_render_template(template, context):  # pylint: disable=unused-argument
     return '<div>{0}</div>'.format(saxutils.escape(repr(context)))
 
 
-def calledback_url(dispatch='score_update'):
-    """A callback url method to use in tests."""
-    return dispatch
+class StubXQueueService:
+    """
+    Stubs out the XQueueService for Capa problem tests.
+    """
+    def __init__(self):
+        self.interface = MagicMock()
+        self.interface.send_to_queue.return_value = (0, 'Success!')
+        self.default_queuename = 'testqueue'
+        self.waittime = 10
 
-xqueue_interface = MagicMock()  # pylint: disable=invalid-name
-xqueue_interface.send_to_queue.return_value = (0, 'Success!')
+    def construct_callback(self, dispatch='score_update'):
+        """A callback url method to use in tests."""
+        return dispatch
 
 
 def test_capa_system(render_template=None):
@@ -72,12 +79,7 @@ def test_capa_system(render_template=None):
         seed=0,
         STATIC_URL='/dummy-static/',
         STATUS_CLASS=Status,
-        xqueue={
-            'interface': xqueue_interface,
-            'construct_callback': calledback_url,
-            'default_queuename': 'testqueue',
-            'waittime': 10
-        },
+        xqueue=StubXQueueService(),
     )
     return the_system
 

common/lib/capa/capa/tests/test_inputtypes.py

@@ -643,9 +643,7 @@ class MatlabTest(unittest.TestCase):
     def test_plot_data(self):
         data = {'submission': 'x = 1234;'}
         response = self.the_input.handle_ajax("plot", data)
-
-        test_capa_system().xqueue['interface'].send_to_queue.assert_called_with(header=ANY, body=ANY)
-
+        self.the_input.capa_system.xqueue.interface.send_to_queue.assert_called_with(header=ANY, body=ANY)
         assert response['success']
         assert self.the_input.input_state['queuekey'] is not None
         assert self.the_input.input_state['queuestate'] == 'queued'
@@ -653,7 +651,7 @@ class MatlabTest(unittest.TestCase):
     def test_plot_data_failure(self):
         data = {'submission': 'x = 1234;'}
         error_message = 'Error message!'
-        test_capa_system().xqueue['interface'].send_to_queue.return_value = (1, error_message)
+        self.the_input.capa_system.xqueue.interface.send_to_queue.return_value = (1, error_message)
         response = self.the_input.handle_ajax("plot", data)
         assert not response['success']
         assert response['message'] == error_message
@@ -740,7 +738,7 @@ class MatlabTest(unittest.TestCase):
         data = {'submission': 'x = 1234;'}
         response = the_input.handle_ajax("plot", data)  # lint-amnesty, pylint: disable=unused-variable
 
-        body = system.xqueue['interface'].send_to_queue.call_args[1]['body']
+        body = system.xqueue.interface.send_to_queue.call_args[1]['body']
         payload = json.loads(body)
         assert 'test_api_key' == payload['token']
         assert '2' == payload['endpoint_version']

common/lib/xmodule/xmodule/capa_module.py

@@ -827,7 +827,7 @@ class ProblemBlock(
             render_template=self.runtime.service(self, 'mako').render_template,
             seed=seed,  # Why do we do this if we have self.seed?
             STATIC_URL=self.runtime.STATIC_URL,
-            xqueue=self.runtime.xqueue,
+            xqueue=self.runtime.service(self, 'xqueue'),
             matlab_api_key=self.matlab_api_key
         )
 
@@ -1746,7 +1746,8 @@ class ProblemBlock(
         if self.lcp.is_queued():
             prev_submit_time = self.lcp.get_recentmost_queuetime()
 
-            waittime_between_requests = self.runtime.xqueue['waittime']
+            xqueue_service = self.runtime.service(self, 'xqueue')
+            waittime_between_requests = xqueue_service.waittime if xqueue_service else 0
             if (current_time - prev_submit_time).total_seconds() < waittime_between_requests:
                 msg = _("You must wait at least {wait} seconds between submissions.").format(
                     wait=waittime_between_requests)