Fix tests

Author: eliotwrobson

src/pytest_pl_grader/plugin.py

@@ -150,8 +150,8 @@ def sandbox(request: pytest.FixtureRequest, data_json: dict[str, Any] | None) ->
             # TODO make this not an assert?
             assert output_level == GradingOutputLevel.FullTraceback
 
-            exception_traceback = response.get("execution_traceback", "")
-            fail_message += f"{os.linesep * 2}Traceback:{os.linesep}{exception_traceback}"
+            if exception_traceback := response.get("execution_traceback", ""):
+                fail_message += f"{os.linesep * 2}{exception_traceback}"
 
             pytest.fail(fail_message, pytrace=False)
 

tests/scenario_root/test_quiz_2_1/expected_outcome.json

@@ -22,7 +22,7 @@
       },
       {
         "max_points": 6,
-        "message": "Student code execution failed with an exception:\nRuntimeError",
+        "message": "Student code execution failed with an exception: RuntimeError",
         "name": "Test analyze_vibration function",
         "outcome": "error",
         "points_frac": 0.0,
@@ -31,7 +31,7 @@
       },
       {
         "max_points": 6,
-        "message": "Student code execution failed with an exception:\nRuntimeError",
+        "message": "Student code execution failed with an exception: RuntimeError",
         "name": "Test analyze_vibration function",
         "outcome": "error",
         "points_frac": 0.0,