Support serializing with the by_alias arg set (#10)

Enables us to define custom aliases for the fields in the Pydantic model, and have the @api decorator serialize the model using those aliases.

django_api_decorator/decorators.py

@@ -31,6 +31,7 @@ def api(
     response_status: int = 200,
     atomic: bool | None = None,
     auth_check: Callable[[HttpRequest], bool] | None = None,
+    serialize_by_alias: bool = False,
 ) -> Callable[[Callable[P, T]], Callable[P, HttpResponse]]:
     """
     Defines an API view. This handles validation of query parameters, parsing of
@@ -49,6 +50,10 @@ def api(
         HTTP status code to use if the view _does not_ return an
         Response object, but rather just the data we should return.
 
+    * serialize_by_alias:
+        Is passed as the by_alias argument to TypeAdapter.dump_json(), making
+        the model use the aliases defined in model_config when serializing.
+
     The request body parsing is done by inspecting the view parameter types. If
     the view has a body parameter, we will try to decode the payload to that
     type. Currently Django Rest Framework serializers and pydantic models are are
@@ -182,7 +187,7 @@ def inner(request: HttpRequest, *args: Any, **kwargs: Any) -> HttpResponse:
                 )
 
             # Encode the response from the view to json and create a response object.
-            payload = response_adapter.dump_json(response)
+            payload = response_adapter.dump_json(response, by_alias=serialize_by_alias)
             return HttpResponse(
                 payload, status=response_status, content_type="application/json"
             )

tests/test_response_encoding.py

@@ -1,32 +1,51 @@
 import random
+import re
 
 import pytest
 from django.http import HttpRequest, JsonResponse
 from django.test.client import Client
 from django.urls import path
-from pydantic import BaseModel
+from pydantic import BaseModel, ConfigDict
 from typing_extensions import TypedDict
 
 from django_api_decorator.decorators import api
 from django_api_decorator.openapi import generate_api_spec
 
 
 class MyTypedDict(TypedDict):
-    a: int
+    an_integer: int
 
 
 class MyPydanticModel(BaseModel):
-    a: int
+    an_integer: int
+
+
+def camel_case(string: str) -> str:
+    """
+    Convert string from snake_case to camelCase
+    """
+
+    _pascal_case = re.sub(r"(?:^|_)(.)", lambda m: m.group(1).upper(), string)
+    return _pascal_case[0].lower() + _pascal_case[1:]
+
+
+class MyCamelCasePydanticModel(BaseModel):
+    model_config = ConfigDict(
+        alias_generator=camel_case,
+        populate_by_name=True,
+    )
+
+    an_integer: int
 
 
 @api(method="GET")
 def view_json_response(r: HttpRequest) -> JsonResponse:
-    return JsonResponse({"a": 1})
+    return JsonResponse({"an_integer": 1})
 
 
 @api(method="GET")
 def view_typed_dict(r: HttpRequest) -> MyTypedDict:
-    return {"a": 1}
+    return {"an_integer": 1}
 
 
 @api(method="GET")
@@ -41,7 +60,12 @@ def view_bool(r: HttpRequest) -> bool:
 
 @api(method="GET")
 def view_pydantic_model(r: HttpRequest) -> MyPydanticModel:
-    return MyPydanticModel(a=1)
+    return MyPydanticModel(an_integer=1)
+
+
+@api(method="GET", serialize_by_alias=True)
+def view_camel_case_pydantic_model(r: HttpRequest) -> MyCamelCasePydanticModel:
+    return MyCamelCasePydanticModel(an_integer=1)
 
 
 @api(method="GET")
@@ -55,18 +79,20 @@ def view_union(r: HttpRequest) -> int | str:
     path("int", view_int),
     path("bool", view_bool),
     path("pydantic-model", view_pydantic_model),
+    path("pydantic-camel-case-model", view_camel_case_pydantic_model),
     path("union", view_union),
 ]
 
 
 @pytest.mark.parametrize(
     "url,expected_response",
     [
-        ("/json-response", b'{"a": 1}'),
-        ("/typed-dict", b'{"a":1}'),
+        ("/json-response", b'{"an_integer": 1}'),
+        ("/typed-dict", b'{"an_integer":1}'),
         ("/int", b"1"),
         ("/bool", b"false"),
-        ("/pydantic-model", b'{"a":1}'),
+        ("/pydantic-model", b'{"an_integer":1}'),
+        ("/pydantic-camel-case-model", b'{"anInteger":1}'),
     ],
 )
 @pytest.mark.urls(__name__)
@@ -105,6 +131,26 @@ def test_schema() -> None:
                     },
                 }
             },
+            "/pydantic-camel-case-model": {
+                "get": {
+                    "operationId": "view_camel_case_pydantic_model",
+                    "description": "",
+                    "tags": ["test_response_encoding"],
+                    "parameters": [],
+                    "responses": {
+                        200: {
+                            "description": "",
+                            "content": {
+                                "application/json": {
+                                    "schema": {
+                                        "$ref": "#/components/schemas/MyCamelCasePydanticModel"  # noqa: E501
+                                    }
+                                }
+                            },
+                        }
+                    },
+                }
+            },
             "/pydantic-model": {
                 "get": {
                     "operationId": "view_pydantic_model",
@@ -189,15 +235,27 @@ def test_schema() -> None:
         },
         "components": {
             "schemas": {
+                "MyCamelCasePydanticModel": {
+                    "properties": {
+                        "anInteger": {"title": "Aninteger", "type": "integer"}
+                    },
+                    "required": ["anInteger"],
+                    "title": "MyCamelCasePydanticModel",
+                    "type": "object",
+                },
                 "MyPydanticModel": {
-                    "properties": {"a": {"title": "A", "type": "integer"}},
-                    "required": ["a"],
+                    "properties": {
+                        "an_integer": {"title": "An Integer", "type": "integer"}
+                    },
+                    "required": ["an_integer"],
                     "title": "MyPydanticModel",
                     "type": "object",
                 },
                 "MyTypedDict": {
-                    "properties": {"a": {"title": "A", "type": "integer"}},
-                    "required": ["a"],
+                    "properties": {
+                        "an_integer": {"title": "An Integer", "type": "integer"}
+                    },
+                    "required": ["an_integer"],
                     "title": "MyTypedDict",
                     "type": "object",
                 },