Seperate SchemaGenerator from Application

starlette/schemas.py

@@ -1,6 +1,7 @@
 import inspect
 import typing
 
+from starlette.requests import Request
 from starlette.responses import Response
 from starlette.routing import BaseRoute, Route
 
@@ -74,6 +75,11 @@ class BaseSchemaGenerator:
         docstring = func_or_method.__doc__
         return yaml.safe_load(docstring) if docstring else {}
 
+    def OpenAPIResponse(self, request: Request) -> Response:
+        routes = request.app.routes
+        schema = self.get_schema(routes=routes)
+        return OpenAPIResponse(schema)
+
 
 class SchemaGenerator(BaseSchemaGenerator):
     def __init__(self, base_schema: dict) -> None:

tests/test_schemas.py

@@ -3,11 +3,12 @@ from starlette.endpoints import HTTPEndpoint
 from starlette.schemas import OpenAPIResponse, SchemaGenerator
 from starlette.testclient import TestClient
 
-app = Starlette()
-app.schema_generator = SchemaGenerator(
+schemas = SchemaGenerator(
     {"openapi": "3.0.0", "info": {"title": "Example API", "version": "1.0"}}
 )
 
+app = Starlette()
+
 
 @app.websocket_route("/ws")
 def ws(session):
@@ -64,11 +65,12 @@ class OrganisationsEndpoint(HTTPEndpoint):
 
 @app.route("/schema", methods=["GET"], include_in_schema=False)
 def schema(request):
-    return OpenAPIResponse(app.schema)
+    return schemas.OpenAPIResponse(request=request)
 
 
 def test_schema_generation():
-    assert app.schema == {
+    schema = schemas.get_schema(routes=app.routes)
+    assert schema == {
         "openapi": "3.0.0",
         "info": {"title": "Example API", "version": "1.0"},
         "paths": {
@@ -109,6 +111,11 @@ def test_schema_generation():
     }
 
 
+def test_schema_generation_legacy():
+    app.schema_generator = schemas
+    assert app.schema == schemas.get_schema(routes=app.routes)
+
+
 EXPECTED_SCHEMA = """
 info:
   title: Example API