Redirect response (#39)

* Minor Request cleanups

* Black formatting

* Add RedirectResponse

* Black formatting

* Clean up test_redirect_response test case

README.md

@@ -134,6 +134,26 @@ class App:
         await response(receive, send)
 ```
 
+### RedirectResponse
+
+Returns an HTTP redirect. Uses a 302 status code by default.
+
+```python
+from starlette import PlainTextResponse, RedirectResponse
+
+
+class App:
+    def __init__(self, scope):
+        self.scope = scope
+
+    async def __call__(self, receive, send):
+        if self.scope['path'] != '/':
+            response = RedirectResponse(url='/')
+        else:
+            response = PlainTextResponse('Hello, world!')
+        await response(receive, send)
+```
+
 ### StreamingResponse
 
 Takes an async generator and streams the response body.

starlette/__init__.py

@@ -3,6 +3,7 @@ from starlette.response import (
     FileResponse,
     HTMLResponse,
     JSONResponse,
+    RedirectResponse,
     Response,
     PlainTextResponse,
     StreamingResponse,
@@ -17,9 +18,10 @@ __all__ = (
     "HTMLResponse",
     "JSONResponse",
     "PlainTextResponse",
+    "RedirectResponse",
     "Response",
     "StreamingResponse",
     "Request",
     "TestClient",
 )
-__version__ = "0.1.16"
+__version__ = "0.1.17"

starlette/datastructures.py

@@ -49,6 +49,10 @@ class URL(str):
     def port(self):
         return self.components.port
 
+    def replace(self, **kwargs):
+        components = self.components._replace(**kwargs)
+        return URL(components.geturl())
+
 
 # Type annotations for valid `__init__` values to QueryParams and Headers.
 StrPairs = typing.Sequence[typing.Tuple[str, str]]

starlette/response.py

@@ -3,6 +3,7 @@ from email.utils import formatdate
 from mimetypes import guess_type
 from starlette.datastructures import MutableHeaders
 from starlette.types import Receive, Send
+from urllib.parse import quote_plus
 import aiofiles
 import json
 import hashlib
@@ -98,6 +99,12 @@ class JSONResponse(Response):
         return json.dumps(content, **self.options).encode("utf-8")
 
 
+class RedirectResponse(Response):
+    def __init__(self, url: str, status_code: int = 302, headers: dict = None) -> None:
+        super().__init__(content=b"", status_code=status_code, headers=headers)
+        self.headers["location"] = quote_plus(url, safe=":/#?&=@[]!$&'()*+,;")
+
+
 class StreamingResponse(Response):
     def __init__(
         self,

tests/test_datastructures.py

@@ -13,6 +13,9 @@ def test_url():
     assert u.query == "abc=123"
     assert u.params == ""
     assert u.fragment == "anchor"
+    new = u.replace(scheme="http")
+    assert new == "http://example.org:123/path/to/somewhere?abc=123#anchor"
+    assert new.scheme == "http"
 
 
 def test_headers():

tests/test_response.py

@@ -1,4 +1,10 @@
-from starlette import FileResponse, Response, StreamingResponse, TestClient
+from starlette.response import (
+    FileResponse,
+    RedirectResponse,
+    Response,
+    StreamingResponse,
+)
+from starlette.testclient import TestClient
 import asyncio
 import os
 
@@ -29,6 +35,23 @@ def test_bytes_response():
     assert response.content == b"xxxxx"
 
 
+def test_redirect_response():
+    def app(scope):
+        async def asgi(receive, send):
+            if scope["path"] == "/":
+                response = Response("hello, world", media_type="text/plain")
+            else:
+                response = RedirectResponse("/")
+            await response(receive, send)
+
+        return asgi
+
+    client = TestClient(app)
+    response = client.get("/redirect")
+    assert response.text == "hello, world"
+    assert response.url == "http://testserver/"
+
+
 def test_streaming_response():
     def app(scope):
         async def numbers(minimum, maximum):