feat: ModelSerializerTestCase

codeforlife/tests/__init__.py

@@ -6,4 +6,5 @@
 """
 
 from .cron import CronTestCase
+from .model_serializer import ModelSerializerTestCase
 from .model_view_set import ModelViewSetTestCase

codeforlife/tests/model_serializer.py

@@ -0,0 +1,63 @@
+"""
+© Ocado Group
+Created on 30/01/2024 at 18:06:31(+00:00).
+
+Base test case for all model serializers.
+"""
+
+import typing as t
+
+from django.db.models import Model
+from django.test import TestCase
+from rest_framework.serializers import ValidationError
+
+from ..serializers import ModelSerializer
+
+AnyModel = t.TypeVar("AnyModel", bound=Model)
+
+
+class ModelSerializerTestCase(TestCase, t.Generic[AnyModel]):
+    """Base for all model serializer test cases."""
+
+    model_serializer_class: t.Type[ModelSerializer[AnyModel]]
+
+    @classmethod
+    def get_model_class(cls) -> t.Type[AnyModel]:
+        """Get the model view set's class.
+
+        Returns:
+            The model view set's class.
+        """
+
+        # pylint: disable-next=no-member
+        return t.get_args(cls.__orig_bases__[0])[  # type: ignore[attr-defined]
+            0
+        ]
+
+    def assert_raises_validation_error(self, code: str, *args, **kwargs):
+        """Assert code block raises a validation error.
+
+        Args:
+            code: The validation code to assert.
+
+        Returns:
+            The assert-raises context which will auto-assert the code.
+        """
+
+        context = self.assertRaises(ValidationError, *args, **kwargs)
+
+        class ContextWrapper:
+            """Wrap context to assert code on exit."""
+
+            def __init__(self, context):
+                self.context = context
+
+            def __enter__(self, *args, **kwargs):
+                return self.context.__enter__(*args, **kwargs)
+
+            def __exit__(self, *args, **kwargs):
+                value = self.context.__exit__(*args, **kwargs)
+                assert self.context.exception.detail[0].code == code
+                return value
+
+        return ContextWrapper(context)