Clean up chat channels when deleting users (#6225)

app/services/users/delete_activity.rb

@@ -8,7 +8,7 @@ module Users
       user.follows.delete_all
       Follow.where(followable_id: user.id, followable_type: "User").delete_all
       user.messages.delete_all
-      user.chat_channel_memberships.delete_all
+      Users::CleanupChatChannels.call(user)
       user.mentions.delete_all
       user.badge_achievements.delete_all
       user.github_repos.delete_all

spec/services/users/delete_spec.rb

@@ -86,4 +86,20 @@ RSpec.describe Users::Delete, type: :service do
       end
     end
   end
+
+  context "when cleaning up chat channels" do
+    let_it_be(:other_user) { create(:user) }
+
+    it "deletes the user's private chat channels" do
+      chat_channel = ChatChannel.create_with_users([user, other_user])
+      described_class.call(user)
+      expect(ChatChannel.find_by(id: chat_channel.id)).to be_nil
+    end
+
+    it "does not delete the user's open channels" do
+      chat_channel = ChatChannel.create_with_users([user, other_user], "open")
+      described_class.call(user)
+      expect(ChatChannel.find_by(id: chat_channel.id)).not_to be_nil
+    end
+  end
 end