From 78ea8a2107010629dd997baf3740fae438c41e3a Mon Sep 17 00:00:00 2001
From: Hiten Shah <hnshah@gmail.com>
Date: Tue, 24 Mar 2026 12:56:25 -0700
Subject: [PATCH] refactor: Move type-only imports into TYPE_CHECKING blocks

Move imports that are only used for type annotations into TYPE_CHECKING
blocks to prevent unnecessary runtime imports and potential circular
import issues.

Changes:
- fastapi/openapi/utils.py: Response
- tests/test_dependency_contextmanager.py: StreamingResponse
- tests/test_route_scope.py: APIRoute

Detected via: ruff check . --select TC002
---
 fastapi/openapi/utils.py                | 6 ++++--
 tests/test_dependency_contextmanager.py | 5 ++++-
 tests/test_route_scope.py               | 5 ++++-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/fastapi/openapi/utils.py b/fastapi/openapi/utils.py
index 8f1852b0cc..a501ca12bd 100644
--- a/fastapi/openapi/utils.py
+++ b/fastapi/openapi/utils.py
@@ -3,7 +3,7 @@ import http.client
 import inspect
 import warnings
 from collections.abc import Sequence
-from typing import Any, Literal, cast
+from typing import Any, Literal, cast, TYPE_CHECKING
 
 from fastapi import routing
 from fastapi._compat import (
@@ -27,7 +27,6 @@ from fastapi.exceptions import FastAPIDeprecationWarning
 from fastapi.openapi.constants import METHODS_WITH_BODY, REF_PREFIX
 from fastapi.openapi.models import OpenAPI
 from fastapi.params import Body, ParamTypes
-from fastapi.responses import Response
 from fastapi.sse import _SSE_EVENT_SCHEMA
 from fastapi.types import ModelNameMap
 from fastapi.utils import (
@@ -39,6 +38,9 @@ from pydantic import BaseModel
 from starlette.responses import JSONResponse
 from starlette.routing import BaseRoute
 
+if TYPE_CHECKING:
+    from fastapi.responses import Response
+
 validation_error_definition = {
     "title": "ValidationError",
     "type": "object",
diff --git a/tests/test_dependency_contextmanager.py b/tests/test_dependency_contextmanager.py
index 5a89934741..b7c7a627b4 100644
--- a/tests/test_dependency_contextmanager.py
+++ b/tests/test_dependency_contextmanager.py
@@ -2,8 +2,11 @@ import json
 
 import pytest
 from fastapi import BackgroundTasks, Depends, FastAPI
-from fastapi.responses import StreamingResponse
 from fastapi.testclient import TestClient
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from fastapi.responses import StreamingResponse
 
 app = FastAPI()
 state = {
diff --git a/tests/test_route_scope.py b/tests/test_route_scope.py
index 792ea66c3a..1e69f38cb1 100644
--- a/tests/test_route_scope.py
+++ b/tests/test_route_scope.py
@@ -1,7 +1,10 @@
 import pytest
 from fastapi import FastAPI, Request, WebSocket, WebSocketDisconnect
-from fastapi.routing import APIRoute, APIWebSocketRoute
 from fastapi.testclient import TestClient
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from fastapi.routing import APIRoute, APIWebSocketRoute
 
 app = FastAPI()