Cant reset Mnesia or a DynamicSupervisor in ExUnit setup for each test

Questions / Help
1

Hello friends, this is my cleaner of Mnesia and Job terminator inside one of my test module, and I try to summarize the codes in another step.

My whole code:

  setup do
    Code.ensure_loaded?(PluginWorker)
    :ok = :mnesia.start()
    :mnesia.create_schema([node()])
    :mnesia.create_table(Queue, Queue.database_config())
    :mnesia.create_table(Event, Event.database_config())
    :ok = :mnesia.wait_for_tables([Queue, Event], 5000)
    :persistent_term.put(:event_status, "ready")
    MishkaInstaller.subscribe("event")

    Queue.new(%{
      worker: PluginWorker,
      error: %{type: :continuously, max_try: 5, delay: 0}
    })

    on_exit(fn ->
      :ok = MishkaInstaller.unsubscribe("event")
      :ok = MishkaInstaller.unsubscribe("queue:job")
      Job.terminate_worker(PluginWorker)
      Queue.delete(worker: PluginWorker)
      {:atomic, :ok} = :mnesia.clear_table(Queue)
      {:atomic, :ok} = :mnesia.clear_table(Event)
      :ok = :mnesia.delete_schema([node()])
      :stopped = :mnesia.stop()
    end)

    :ok
  end

As I summarize this I have 2 lines; the first one create inside Mnesia and the other terminate the job which is a PartitionSupervisor -> DynamicSupervisor

 Queue.new(%{
      worker: PluginWorker,
      error: %{type: :continuously, max_try: 5, delay: 0}
    })

#####
Job.terminate_worker(PluginWorker)

Now what is my problem; it terminates the job pid and returns the ok response, but again when I want to create I can see the job is not terminated!!

This is my terminate function

  def terminate(pid) do
    DynamicSupervisor.terminate_child(
      {:via, PartitionSupervisor, {MishkaJobWorkerSupervisor, self()}},
      pid
    )
  end

I can not be able to reset all things for each test what you suggest me for this?

by the way, I forced to change all dirty way of my mnesia to transaction to lock the data when is writing!! but the problem is my DynamicSupervisor.

Thank you in advance

2

Regarding resetting mnesia: This is how I run test with mnesia in ecto_qlc ecto_qlc/test/support/data_case.ex at main · Schultzer/ecto_qlc · GitHub I usually create a temp directory for the data. But I guess you could always test in memory with a random name for your schema, and lastly, you might be able to wrap the test in a transaction, akin to how ecto sandbox works.

1 Like
3

Thank you. I already thought about this and other things you said, but my first problem is that I can’t kill all the children of dynamic-supervisor or a child in unit test, unfortunately :face_with_spiral_eyes:.

this part of my code has error in unit test

Unfortunately, I didn’t think about this from the beginning due to my lack of experience in mnesia, and in the same way, I use mnesia internally, which is very dependent on the module I am using, and it is very difficult to change it with random names. All codes must be rewritten from scratch

4

You would need to stop it first ExUnit.Callbacks — ExUnit v1.16.3 and then exit the pids Process — Elixir v1.17.0-rc.1

1 Like
5

Yes, I am using it, but it creates another problem for me :)) for example I lost Phoenix PubSub in my tests. I am trying re-write whole my project.
I think that I directed my project forward very badly, and even if these problems are solved now, they may increase in the future.

6

I want to say thank you I got some idea from your code and mix with my code and fix the problem, for now!