Added parsing of atol and rtol when they are not numbers

app/evaluation.py

@@ -24,6 +24,18 @@ def evaluation_function(response, answer, params) -> dict:
     rtol = params.get("rtol", 0)
     atol = params.get("atol", 0)
 
+    if isinstance(rtol, str):
+        try:
+            rtol = float(rtol)
+        except Exception as e:
+            raise Exception("Relative tolerance must be given as a number.") from e
+
+    if isinstance(atol, str):
+        try:
+            atol = float(atol)
+        except Exception as e:
+            raise Exception("Absolute tolerance must be given as a number.") from e
+
     is_correct = None
     real_diff = None
 

app/evaluation_tests.py

@@ -244,5 +244,65 @@ def test_response_is_not_number(self):
         self.assertEqual(response.get("is_correct"), False)
         self.assertEqual("Please enter a number." in response.get("feedback"), True)
 
+    def test_atol_is_parseable_string(self):
+        body = {
+            "response": 2,
+            "answer": 2.1,
+            "params": {
+                "atol": "0.2"
+            },
+        }
+
+        response = evaluation_function(body['response'], body['answer'],
+                                       body.get('params', {}))
+        self.assertEqual(response.get("is_correct"), True)
+
+    def test_atol_is_not_parseable_string(self):
+        body = {
+            "response": 2,
+            "answer": 2.1,
+            "params": {
+                "atol": "nonsense"
+            },
+        }
+
+        self.assertRaises(
+            Exception,
+            evaluation_function,
+            body["response"],
+            body["answer"],
+            body["params"],
+        )
+
+    def test_rtol_is_parseable_string(self):
+        body = {
+            "response": 2,
+            "answer": 2.1,
+            "params": {
+                "rtol": "0.1"
+            },
+        }
+
+        response = evaluation_function(body['response'], body['answer'],
+                                       body.get('params', {}))
+        self.assertEqual(response.get("is_correct"), True)
+
+    def test_rtol_is_not_parseable_string(self):
+        body = {
+            "response": 2,
+            "answer": 2.1,
+            "params": {
+                "rtol": "nonsense"
+            },
+        }
+
+        self.assertRaises(
+            Exception,
+            evaluation_function,
+            body["response"],
+            body["answer"],
+            body["params"],
+        )
+
 if __name__ == "__main__":
     unittest.main()