Allow support for exclusion/inclusion of none and unset fields in OpenAPI schema

fastapi/applications.py

@@ -84,6 +84,8 @@ def __init__(
         generate_unique_id_function: Callable[[routing.APIRoute], str] = Default(
             generate_unique_id
         ),
+        openapi_schema_exclude_unset: bool = False,
+        openapi_schema_exclude_none: bool = True,
         **extra: Any,
     ) -> None:
         self._debug: bool = debug
@@ -105,6 +107,8 @@ def __init__(
         self.extra = extra
         self.openapi_version = "3.0.2"
         self.openapi_schema: Optional[Dict[str, Any]] = None
+        self.openapi_schema_exclude_unset = openapi_schema_exclude_unset
+        self.openapi_schema_exclude_none = openapi_schema_exclude_none
         if self.openapi_url:
             assert self.title, "A title must be provided for OpenAPI, e.g.: 'My API'"
             assert self.version, "A version must be provided for OpenAPI, e.g.: '2.1.0'"
@@ -208,6 +212,8 @@ def openapi(self) -> Dict[str, Any]:
                 routes=self.routes,
                 tags=self.openapi_tags,
                 servers=self.servers,
+                exclude_unset=self.openapi_schema_exclude_unset,
+                exclude_none=self.openapi_schema_exclude_none,
             )
         return self.openapi_schema
 

fastapi/openapi/utils.py

@@ -402,6 +402,8 @@ def get_openapi(
     terms_of_service: Optional[str] = None,
     contact: Optional[Dict[str, Union[str, Any]]] = None,
     license_info: Optional[Dict[str, Union[str, Any]]] = None,
+    exclude_unset: bool = False,
+    exclude_none: bool = True,
 ) -> Dict[str, Any]:
     info: Dict[str, Any] = {"title": title, "version": version}
     if description:
@@ -445,4 +447,9 @@ def get_openapi(
     output["paths"] = paths
     if tags:
         output["tags"] = tags
-    return jsonable_encoder(OpenAPI(**output), by_alias=True, exclude_none=True)  # type: ignore
+    return jsonable_encoder(  # type: ignore
+        OpenAPI(**output),
+        by_alias=True,
+        exclude_unset=exclude_unset,
+        exclude_none=exclude_none,
+    )

tests/test_get_openapi_schema.py

@@ -0,0 +1,57 @@
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+app = FastAPI(
+    openapi_schema_exclude_unset=True,
+    openapi_schema_exclude_none=False,
+)
+
+
+@app.get(
+    "/items",
+    responses={
+        200: {"content": {"application/json": {"example": {"id": None, "value": 50}}}}
+    },
+)
+def get_items():
+    return {"id": "foo", "value": 50}
+
+
+client = TestClient(app)
+
+
+openapi_schema = {
+    "openapi": "3.0.2",
+    "info": {"title": "FastAPI", "version": "0.1.0"},
+    "paths": {
+        "/items": {
+            "get": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {},
+                                "example": {"id": None, "value": 50},
+                            }
+                        },
+                    }
+                },
+                "summary": "Get Items",
+                "operationId": "get_items_items_get",
+            }
+        }
+    },
+}
+
+
+def test_openapi_schema():
+    response = client.get("/openapi.json")
+    assert response.status_code == 200, response.text
+    assert response.json() == openapi_schema
+
+
+def test_default_get_items():
+    response = client.get("/items")
+    assert response.status_code == 200, response.text
+    assert response.json() == {"id": "foo", "value": 50}