Improve test coverage for exception handler

Author: gripep

drf_simple_api_errors/exception_handler.py

@@ -44,6 +44,8 @@ def exception_handler(exc: Exception, context: ExceptionHandlerContext) -> Respo
     # This is because it's not good practice to expose the details of
     # unhandled exceptions to the client.
     if not isinstance(exc, exceptions.APIException):
+        # Raise a ServerError exception instead of returning None, because
+        # we can control the response format this way.
         logger.info("Server error (500) from unexpected exception.", exc_info=True)
         return ServerError
 

drf_simple_api_errors/formatter.py

@@ -101,12 +101,10 @@ def format_exc(exc: exceptions.APIException) -> APIErrorResponseDict:
     # Create the API error response based on the exception detail...
     if isinstance(exc_detail, dict):
         return _format_exc_detail_dict(data, exc_detail)
-    elif isinstance(exc_detail, list):
-        # If the exception detail is a list, we will return all the errors
-        # in a single list.
-        return _format_exc_detail_list(data, exc_detail)
     else:
-        return data.to_dict()
+        # If the exception detail in not a dict, it must be a list, and
+        # we will return all the errors in a single list.
+        return _format_exc_detail_list(data, exc_detail)
 
 
 def _format_exc_detail_dict(

tests/test_exception_handler.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+from drf_simple_api_errors import exceptions
 from drf_simple_api_errors.exception_handler import exception_handler
 from tests.utils import render_response
 
@@ -399,3 +400,12 @@ def test_drf_throttled(self, mocker, wait, expected_detail):
             "invalid_params": None,
         }
         assert render_response(response.data) == expected_response
+
+    def test_unexpected_exception(self, mocker):
+        """
+        Test the exception handler for unexpected exceptions.
+        This should return a 500 Internal Server Error response.
+        """
+        exc = Exception("Unexpected error")
+        response = exception_handler(exc, mocker.Mock())
+        assert response is exceptions.ServerError

tests/test_formatter.py

@@ -207,21 +207,32 @@ def test_exc_detail_is_dict_with_non_field_errors_formats(self, mocker, exc_deta
         assert data["invalid_params"] is None
 
     @pytest.mark.parametrize(
-        "exc_detail",
+        "exc_detail, expected_detail",
         [
-            "This is a non-field error.",
-            ["This is a non-field error."],
+            ("This is a non-field error.", ["This is a non-field error."]),
+            (["This is a non-field error."], ["This is a non-field error."]),
+            (
+                ["This is a non-field error.", "Another error."],
+                ["This is a non-field error.", "Another error."],
+            ),
+            (
+                [
+                    "This is a non-field error.",
+                    ["Another error.", "Yet another error."],
+                ],
+                ["This is a non-field error.", "Another error.", "Yet another error."],
+            ),
         ],
     )
-    def test_exc_detail_is_list_formats(self, exc_detail):
+    def test_exc_detail_is_list_formats(self, exc_detail, expected_detail):
         """
         Test that when the exception detail is a list or a string,
         the detail is set to the error messages list and invalid_params is `None`.
         """
         exc = drf_exceptions.ValidationError(exc_detail)
 
         data = formatter.format_exc(exc)
-        assert data["detail"] == ["This is a non-field error."]
+        assert data["detail"] == expected_detail
         assert data["invalid_params"] is None
 
     def test_format_exc_detail_is_list_error_when_unexpected_type(self):

tests/test_utils.py

@@ -14,6 +14,9 @@ class TestCamelize:
             ("first_name", "firstName"),
             ("family_tree_name", "familyTreeName"),
             ("very_long_last_name_and_first_name", "veryLongLastNameAndFirstName"),
+            # This is a special case where the underscore is at the start
+            # and should be removed, and the next character should be capitalized.
+            ("_special", "Special"),
         ],
     )
     def test_with_camelize_settings_true(self, mocker, field_input, expected_output):
@@ -33,6 +36,7 @@ def test_with_camelize_settings_true(self, mocker, field_input, expected_output)
                 "very_long_last_name_and_first_name",
                 "very_long_last_name_and_first_name",
             ),
+            ("_special", "_special"),
         ],
     )
     def test_with_camelize_settings_false(self, field_input, expected_output):