feat: is_self permission

Author: SKairinos

codeforlife/permissions/__init__.py

@@ -7,4 +7,5 @@
 
 from .allow_none import AllowNone
 from .is_cron_request_from_google import IsCronRequestFromGoogle
+from .is_self import IsSelf
 from .operators import AND, NOT, OR, Permission

codeforlife/permissions/is_self.py

@@ -0,0 +1,42 @@
+"""
+© Ocado Group
+Created on 08/02/2024 at 11:19:37(+00:00).
+"""
+
+import typing as t
+
+from rest_framework.permissions import IsAuthenticated
+
+
+class IsSelf(IsAuthenticated):
+    """Request's user must be the selected user."""
+
+    def __init__(
+        self,
+        lookup_field: str = "pk",
+        lookup_url_kwarg: t.Optional[str] = None,
+    ):
+        """Initialize permission.
+
+        Args:
+            lookup_field: The field used to uniquely identify a user.
+            lookup_url_kwarg: The key for the url arg used to lookup the user.
+        """
+
+        super().__init__()
+        self.lookup_field = lookup_field
+        self.lookup_url_kwarg = lookup_url_kwarg or lookup_field
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, self.__class__)
+            and self.lookup_field == other.lookup_field
+            and self.lookup_url_kwarg == other.lookup_url_kwarg
+        )
+
+    def has_permission(self, request, view):
+        return (
+            super().has_permission(request, view)
+            and getattr(request.user, self.lookup_field)
+            == view.kwargs[self.lookup_url_kwarg]
+        )