Simplify (request.cookies.)getlist function (#2838)

* Remove the default argument to all uses of `getlist` in Sanic in case none are found. Previously it defaulted to returning `None`. Instead return an empty list which is sensible and avoids ambiguity with return types.

* Keep default param

* squash

* format

---------

Co-authored-by: L. Kärkkäinen <Tronic@users.noreply.github.com>
Co-authored-by: Adam Hopkins <adam@amhopkins.com>

Author: Tronic

sanic/cookies/request.py

@@ -155,8 +155,8 @@ def get(self, name: str, default: Optional[Any] = None) -> Optional[Any]:
             return super().get(name, default)
 
     def getlist(
-        self, name: str, default: Optional[Any] = None
-    ) -> Optional[Any]:
+        self, name: str, default: Optional[List[Any]] = None
+    ) -> List[Any]:
         try:
             return self._get_prefixed_cookie(name)
         except KeyError:

sanic/request/parameters.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Any, Optional
+from typing import Any, List, Optional
 
 
 class RequestParameters(dict):
@@ -19,15 +19,15 @@ def get(self, name: str, default: Optional[Any] = None) -> Optional[Any]:
         return super().get(name, [default])[0]
 
     def getlist(
-        self, name: str, default: Optional[Any] = None
-    ) -> Optional[Any]:
+        self, name: str, default: Optional[List[Any]] = None
+    ) -> List[Any]:
         """Return the entire list
 
         Args:
             name (str): The name of the parameter
-            default (Optional[Any], optional): The default value. Defaults to None.
+            default (Optional[List[Any]], optional): The default value. Defaults to None.
 
         Returns:
-            Optional[Any]: The entire list
+            list[Any]: The entire list of values or [] if not found
         """  # noqa: E501
-        return super().get(name, default)
+        return super().get(name, default) or []

tests/test_cookies.py

@@ -24,9 +24,7 @@ def test_request_cookies():
     assert c.getlist("foo") == ["one", "two"]
     assert c.getlist("abc") == ["xyz"]
     assert c.getlist("") == ["bare", "bare2"]
-    assert (
-        c.getlist("bare") is None
-    )  # [] might be sensible but we got None for now
+    assert c.getlist("bare") == []
 
 
 # ------------------------------------------------------------ #
@@ -461,10 +459,11 @@ async def handler(request: Request):
                     "four": request.cookies.get("four", "fallback"),
                 },
                 "getlist": {
-                    "one": request.cookies.getlist("one", ["fallback"]),
-                    "two": request.cookies.getlist("two", ["fallback"]),
-                    "three": request.cookies.getlist("three", ["fallback"]),
-                    "four": request.cookies.getlist("four", ["fallback"]),
+                    "one": request.cookies.getlist("one"),
+                    "two": request.cookies.getlist("two"),
+                    "three": request.cookies.getlist("three"),
+                    "four": request.cookies.getlist("four"),
+                    "five": request.cookies.getlist("five", ["fallback"]),
                 },
                 "getattr": {
                     "one": request.cookies.one,
@@ -500,7 +499,8 @@ async def handler(request: Request):
             "one": ["1"],
             "two": ["2"],
             "three": ["3"],
-            "four": ["fallback"],
+            "four": [],
+            "five": ["fallback"],
         },
         "getattr": {
             "one": "1",