Added del cookie and default path

docs/cookies.md

@@ -32,12 +32,39 @@ async def test(request):
     return response
 ```
 
+## Deleting cookies
+
+Cookies can be removed semantically or explicitly.
+
+```python
+from sanic.response import text
+
+@app.route("/cookie")
+async def test(request):
+    response = text("Time to eat some cookies muahaha")
+    
+    # This cookie will be set to expire in 0 seconds
+    del response.cookies['kill_me']
+    
+    # This cookie will self destruct in 5 seconds
+    response.cookies['short_life'] = 'Glad to be here'
+    response.cookies['short_life']['max-age'] = 5
+    del response.cookies['favorite_color']
+    
+    # This cookie will remain unchanged
+    response.cookies['favorite_color'] = 'blue'
+    response.cookies['favorite_color'] = 'pink'
+    del response.cookies['favorite_color']
+    
+    return response
+```
+
 Response cookies can be set like dictionary values and have the following
 parameters available:
 
 - `expires` (datetime): The time for the cookie to expire on the
                         client's browser.
-- `path` (string): The subset of URLs to which this cookie applies.
+- `path` (string): The subset of URLs to which this cookie applies.  Defaults to 0.
 - `comment` (string): A comment (metadata).
 - `domain` (string): Specifies the domain for which the cookie is valid. An
            explicitly specified domain must always start with a dot.

sanic/cookies.py

@@ -42,8 +42,9 @@ class CookieJar(dict):
     """
     CookieJar dynamically writes headers as cookies are added and removed
     It gets around the limitation of one header per name by using the
-    MultiHeader class to provide a unique key that encodes to Set-Cookie
+    MultiHeader class to provide a unique key that encodes to Set-Cookie.
     """
+
     def __init__(self, headers):
         super().__init__()
         self.headers = headers
@@ -54,6 +55,7 @@ class CookieJar(dict):
         cookie_header = self.cookie_headers.get(key)
         if not cookie_header:
             cookie = Cookie(key, value)
+            cookie['path'] = '/'
             cookie_header = MultiHeader("Set-Cookie")
             self.cookie_headers[key] = cookie_header
             self.headers[cookie_header] = cookie
@@ -62,8 +64,14 @@ class CookieJar(dict):
             self[key].value = value
 
     def __delitem__(self, key):
-        del self.cookie_headers[key]
+        if key not in self.cookie_headers:
-        return super().__delitem__(key)
+            self[key] = ''
+            self[key]['max-age'] = 0
+        else:
+            cookie_header = self.cookie_headers[key]
+            del self.headers[cookie_header]
+            del self.cookie_headers[key]
+            return super().__delitem__(key)
 
 
 class Cookie(dict):

tests/test_cookies.py

@@ -3,6 +3,7 @@ from http.cookies import SimpleCookie
 from sanic import Sanic
 from sanic.response import json, text
 from sanic.utils import sanic_endpoint_test
+import pytest
 
 
 # ------------------------------------------------------------ #
@@ -54,4 +55,23 @@ def test_cookie_options():
     response_cookies.load(response.headers.get('Set-Cookie', {}))
 
     assert response_cookies['test'].value == 'at you'
-    assert response_cookies['test']['httponly'] == True
+    assert response_cookies['test']['httponly'] == True
+
+def test_cookie_deletion():
+    app = Sanic('test_text')
+
+    @app.route('/')
+    def handler(request):
+        response = text("OK")
+        del response.cookies['i_want_to_die']
+        response.cookies['i_never_existed'] = 'testing'
+        del response.cookies['i_never_existed']
+        return response
+
+    request, response = sanic_endpoint_test(app)
+    response_cookies = SimpleCookie()
+    response_cookies.load(response.headers.get('Set-Cookie', {}))
+
+    assert int(response_cookies['i_want_to_die']['max-age']) == 0
+    with pytest.raises(KeyError):
+        hold_my_beer = response.cookies['i_never_existed']