Custom permissions messages don't work with logical operators

[MrCordeiro]

I was having trouble implementing a custom error message for classes that use logical operators. For example:

class MyViewSet(ModelViewSet):
    permission_classes = [IsAdminUser | IsRequestUser]

class IsAdminUser(BasePermission):
    message = "What me? Admin? No, no, no. I'm just the janitor."

    def has_permission(self, request, view):
        ...

Will yield the following response data: {'detail': ErrorDetail(string='You do not have permission to perform this action.', code='permission_denied')}

This is because the OperationHolderMixin lacks a message attribute for the check_permissions method to pass forward.

Does it make sense to add logic that determine how logical permissions should deal with with custom messages of their children? For example:

• if one failed permission class has a message attribute and the other doesn't, use that message;
• if two failed permission classes have a message attribute, use the first one.