🐛(backend) fix blackboard LTI roles parsing

Parsing LTI roles sent by blackboard was broken.

Fixes #2676

CHANGELOG.md

@@ -8,6 +8,10 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Fixed
+
+- Fix blackboard LTI roles parsing
+
 ## [5.5.2] - 2024-12-19
 
 ### Added

src/backend/marsha/core/lti/__init__.py

@@ -265,7 +265,7 @@ def roles(self):
         """
         roles = self.request.POST.get("roles", "")
         # remove LIS roles prefix
-        roles = re.sub(r"^urn:lti:instrole:ims/lis/", "", roles)
+        roles = re.sub(r"urn:lti:(inst)?role:ims/lis/", "", roles)
         # Remove all spaces from the string and extra trailing or leading commas
         roles = re.sub(r"[\s+]", "", roles).strip(",")
         # Return a set of the roles mentioned in the request

src/backend/marsha/core/tests/lti/tests.py

@@ -97,15 +97,16 @@ def test_lti_video_instructor(self):
             ", staff",  # a leading comma should be ignored
             "staff,",  # a trailing comma should be ignored
             "urn:lti:instrole:ims/lis/Instructor",  # the LIS role identifier should be recognized
+            "urn:lti:role:ims/lis/Instructor,urn:lti:instrole:ims/lis/Faculty",
         ]:
             request = self.factory.post("/", {"roles": roles_string})
             lti = LTI(request, uuid.uuid4())
-            self.assertTrue(lti.is_instructor)
+            self.assertTrue(lti.is_instructor, roles_string)
 
         for roles_string in ["", "instructori", "student", "administrator,student"]:
             request = self.factory.post("/", {"roles": roles_string})
             lti = LTI(request, uuid.uuid4())
-            self.assertFalse(lti.is_instructor)
+            self.assertFalse(lti.is_instructor, roles_string)
 
     @mock.patch.object(lti_module, "verify_request_common", return_value=True)
     def test_lti_passport_unknown(self, mock_verify):