Support str and datetime on expires parameter on the set_cookie method

starlette/responses.py

@@ -4,6 +4,7 @@
 import stat
 import sys
 import typing
+from datetime import datetime, timezone
 from email.utils import formatdate
 from functools import partial
 from mimetypes import guess_type as mimetypes_guess_type
@@ -35,6 +36,12 @@ def guess_type(
     return mimetypes_guess_type(url, strict)
 
 
+# Format based on MDN HTTP documentation on Set-Cookie and Date format
+# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie
+# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Date
+COOKIE_DATETIME_FORMAT = "%a, %d %b %Y %H:%M:%S GMT"
+
+
 class Response:
     media_type = None
     charset = "utf-8"
@@ -105,7 +112,7 @@ def set_cookie(
         key: str,
         value: str = "",
         max_age: typing.Optional[int] = None,
-        expires: typing.Optional[int] = None,
+        expires: typing.Optional[typing.Union[datetime, int]] = None,
         path: str = "/",
         domain: typing.Optional[str] = None,
         secure: bool = False,
@@ -117,7 +124,10 @@ def set_cookie(
         if max_age is not None:
             cookie[key]["max-age"] = max_age
         if expires is not None:
-            cookie[key]["expires"] = expires
+            if isinstance(expires, datetime):
+                cookie[key]["expires"] = expires.strftime(COOKIE_DATETIME_FORMAT)
+            else:
+                cookie[key]["expires"] = expires
         if path is not None:
             cookie[key]["path"] = path
         if domain is not None:
@@ -148,7 +158,7 @@ def delete_cookie(
         self.set_cookie(
             key,
             max_age=0,
-            expires=0,
+            expires=datetime.now(timezone.utc),
             path=path,
             domain=domain,
             secure=secure,

tests/test_responses.py

@@ -1,4 +1,7 @@
 import os
+import re
+from datetime import datetime, timedelta, timezone
+from http.cookies import SimpleCookie
 
 import anyio
 import pytest
@@ -309,6 +312,61 @@ async def app(scope, receive, send):
     assert response.text == "Hello, world!"
 
 
+def test_set_cookie_with_expire_datetime(test_client_factory):
+    async def app(scope, receive, send):
+        response = Response("Hello, world!", media_type="text/plain")
+        now = datetime.now(timezone.utc)
+        expires = now + timedelta(minutes=1)
+        response.set_cookie(
+            "mycookie",
+            "myvalue",
+            max_age=10,
+            expires=expires,
+            path="/",
+            domain="localhost",
+            secure=True,
+            httponly=True,
+            samesite="none",
+        )
+        await response(scope, receive, send)
+
+    client = test_client_factory(app)
+    response = client.get("/")
+    cookie: SimpleCookie = SimpleCookie(response.headers.get("set-cookie"))
+
+    assert cookie["mycookie"]
+
+
+def test_set_cookie_expire_format(test_client_factory):
+    async def app(scope, receive, send):
+        response = Response("Hello, world!", media_type="text/plain")
+        now = datetime.now(timezone.utc)
+        expires = now + timedelta(minutes=1)
+        response.set_cookie(
+            "mycookie",
+            "myvalue",
+            max_age=10,
+            expires=expires,
+            path="/",
+            domain="localhost",
+            secure=True,
+            httponly=True,
+            samesite="none",
+        )
+        await response(scope, receive, send)
+
+    client = test_client_factory(app)
+    response = client.get("/")
+    cookie: SimpleCookie = SimpleCookie(response.headers.get("set-cookie"))
+
+    expires = cookie["mycookie"]["expires"]
+
+    # Date format spec from
+    # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Date
+    pattern = r"\w{3}, \d{2} \w{3} \d{4} \d{2}:\d{2}:\d{2}"
+    assert re.search(pattern, expires)
+
+
 def test_delete_cookie(test_client_factory):
     async def app(scope, receive, send):
         request = Request(scope, receive)