Merge pull request #1819 from edx/anton/fix-lti-scores

Fix LTI max_score method.

common/lib/xmodule/xmodule/lti_module.py

@@ -89,7 +89,13 @@ class LTIFields(object):
     custom_parameters = List(help="Custom parameters (vbid, book_location, etc..)", scope=Scope.settings)
     open_in_a_new_page = Boolean(help="Should LTI be opened in new page?", default=True, scope=Scope.settings)
     graded = Boolean(help="Grades will be considered in overall score.", default=False, scope=Scope.settings)
-    weight = Float(help="Weight for student grades.", default=1.0, scope=Scope.settings)
+    weight = Float(
+        help="Weight for student grades.",
+        default=1.0,
+        scope=Scope.settings,
+        values={"min": 0},
+    )
+    has_score = Boolean(help="Does this LTI module have score?", default=False, scope=Scope.settings)
 
 
 class LTIModule(LTIFields, XModule):
@@ -376,7 +382,7 @@ def oauth_params(self, custom_parameters, client_key, client_secret):
         return params
 
     def max_score(self):
-        return self.weight
+        return self.weight if self.has_score else None
 
 
     @XBlock.handler
@@ -582,6 +588,5 @@ class LTIDescriptor(LTIFields, MetadataOnlyEditingDescriptor, EmptyDataRawDescri
     """
     Descriptor for LTI Xmodule.
     """
-    has_score = True
     module_class = LTIModule
     grade_handler = module_attr('grade_handler')

common/lib/xmodule/xmodule/tests/test_lti_unit.py

@@ -194,6 +194,7 @@ def test_good_request(self):
         Response from Tool Provider is correct.
         """
         self.xmodule.verify_oauth_body_sign = Mock()
+        self.xmodule.has_score = True
         request = Request(self.environ)
         request.body = self.get_request_body()
         response = self.xmodule.grade_handler(request, '')
@@ -249,3 +250,16 @@ def test_verify_oauth_body_sign(self):
     def test_client_key_secret(self):
         pass
 
+    def test_max_score(self):
+        self.xmodule.weight = 100.0
+
+        self.xmodule.graded = True
+        self.assertEqual(self.xmodule.max_score(), None)
+
+        self.xmodule.has_score = True
+        self.assertEqual(self.xmodule.max_score(), 100.0)
+
+        self.xmodule.graded = False
+        self.assertEqual(self.xmodule.max_score(), 100.0)
+
+

lms/djangoapps/courseware/features/lti.feature

@@ -44,8 +44,8 @@ Feature: LMS.LTI component
   Scenario: Graded LTI component in LMS is correctly works
   Given the course has correct LTI credentials
   And the course has an LTI component with correct fields:
-  | open_in_a_new_page | weight | is_graded |
-  | False              | 10     | True      |
+  | open_in_a_new_page | weight | is_graded | has_score |
+  | False              | 10     | True      | True |
   And I submit answer to LTI question
   And I click on the "Progress" tab
   Then I see text "Problem Scores: 5/10"