From 5399ab793189b5aa7ccc15ed31c849b4e25e8aeb Mon Sep 17 00:00:00 2001
From: Chris Muthig <camuthig@gmail.com>
Date: Sat, 11 May 2024 16:36:42 -0600
Subject: [PATCH] Use serialization aliases for responses in OpenAPI schema

When generating JSON schemas from the Pydantic types, the `mode` must be
set in order for the corret aliases to be used. The default is to
generate the schema for validation mode, which means that for building
response schemas, the mode needs to be explicitly set to serialization.
---
 ninja/openapi/schema.py      |  6 +++++-
 tests/test_openapi_schema.py | 26 ++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/ninja/openapi/schema.py b/ninja/openapi/schema.py
index 72226e770..cf3eee0b4 100644
--- a/ninja/openapi/schema.py
+++ b/ninja/openapi/schema.py
@@ -4,6 +4,8 @@
 from http.client import responses
 from typing import TYPE_CHECKING, Any, Dict, Generator, List, Optional, Set, Tuple
 
+from pydantic.json_schema import JsonSchemaMode
+
 from ninja.constants import NOT_SET
 from ninja.operation import Operation
 from ninja.params.models import TModel, TModels
@@ -207,6 +209,7 @@ def _create_schema_from_model(
         model: TModel,
         by_alias: bool = True,
         remove_level: bool = True,
+        mode: JsonSchemaMode = "validation",
     ) -> Tuple[DictStrAny, bool]:
         if hasattr(model, "__ninja_flatten_map__"):
             schema = self._flatten_schema(model)
@@ -215,6 +218,7 @@ def _create_schema_from_model(
                 ref_template=REF_TEMPLATE,
                 by_alias=by_alias,
                 schema_generator=NinjaGenerateJsonSchema,
+                mode=mode,
             ).copy()
 
         # move Schemas from definitions
@@ -284,7 +288,7 @@ def responses(self, operation: Operation) -> Dict[int, DictStrAny]:
             if model not in [None, NOT_SET]:
                 # ::TODO:: test this: by_alias == True
                 schema = self._create_schema_from_model(
-                    model, by_alias=operation.by_alias
+                    model, by_alias=operation.by_alias, mode="serialization"
                 )[0]
                 details[status]["content"] = {
                     self.api.renderer.media_type: {"schema": schema}
diff --git a/tests/test_openapi_schema.py b/tests/test_openapi_schema.py
index aec67f472..e4d683bb4 100644
--- a/tests/test_openapi_schema.py
+++ b/tests/test_openapi_schema.py
@@ -942,3 +942,29 @@ def get_employees(request):
     paged_employee_out = schema["components"]["schemas"]["PagedEmployeeOut"]
     # a default value shouldn't be specified automatically
     assert "default" not in paged_employee_out["properties"]["data"]
+
+
+def test_renders_responses_with_serialization_alias():
+    api = NinjaAPI(renderer=TestRenderer)
+
+    class ResponseWithSerializationAlias(Schema):
+        my_field: str = Field(..., serialization_alias="myFieldName")
+
+    @api.get(
+        "/test-with-serialization-alias/",
+        response=ResponseWithSerializationAlias,
+        by_alias=True,
+    )
+    def method_test_with_serialization_alias(
+        request,
+    ):
+        return ResponseWithSerializationAlias(my_field="Field Value")
+
+    schema = api.get_openapi_schema()
+
+    assert (
+        "myFieldName"
+        in schema["components"]["schemas"]["ResponseWithSerializationAlias"][
+            "properties"
+        ]
+    )