Invert method's naming

Signed-off-by: Rémy Coutable <remy@rymai.me>

app/services/members/destroy_service.rb

@@ -17,7 +17,7 @@ module Members
       member = find_member!(scope)
-      raise Gitlab::Access::AccessDeniedError if cannot_destroy_member?(member)
+      raise Gitlab::Access::AccessDeniedError unless can_destroy_member?(member)
       AuthorizedDestroyService.new(member, current_user).execute
     end
@@ -35,8 +35,8 @@ module Members
       end
     end
-    def cannot_destroy_member?(member)
-      !member || !can?(current_user, action_member_permission(:destroy, member), member)
+    def can_destroy_member?(member)
+      member && can?(current_user, action_member_permission(:destroy, member), member)
     end
   end
 end

spec/requests/api/access_requests_spec.rb

@@ -213,7 +213,7 @@ describe API::AccessRequests, api: true  do
           end.to change { source.requesters.count }.by(-1)
         end
-        context 'user_id matches a member' do
+        context 'user_id matches a member, not an access requester' do
           it 'returns 404' do
             expect do
               delete api("/#{source_type.pluralize}/#{source.id}/access_requests/#{developer.id}", master)