Advice on test startup times

[jc00ke]

First off, thanks for veil! It's pretty much exactly what I need for this project.

One sticky point is that Quantum adds a significant delay to starting up the app when in test mode. I'm seeing upwards of 5s just to boot Quantum up. I'm wondering if you have any suggestions as to how to alleviate that?

[zanderxyz]

Hi Jesse,

I can think of a workaround but it's a bit messy, there must be a better way. I'll raise an issue and ask the Quantum contributors.

My workaround would involve:

1. Update the Veil mix file to only load Quantum if in :dev or :prod.
   {:quantum, "~> 2.3", only: [:dev, :prod]},
   This change by itself will cause mix test to crash as Quantum.Scheduler can no longer be found.

2. Create a dummy Quantum.Scheduler module that is empty and only load it if in :test environment:
   {:quantum, path: "/your_path/quantum", only: :test} mix test` will still crash because the Veil app is trying to start it's Scheduler and failing.

3. Add config :veil, :environment, Mix.env() to your config.exs
   Just so the app knows what environment it's in when it is running.

4. Update the veil.ex file inside the Veil repo to only start the Veil Scheduler if not in :test environment:

# delete worker(Veil.Scheduler, []), from row 13

# change the supervisor start function on row 46 to:
Supervisor.start_link(add_scheduler(children), opts)

# add this lower down
defp add_scheduler(children) do
    import Supervisor.Spec, only: [worker: 2]

    if Application.get_env(:veil, :environment) != :test do
      [worker(Veil.Scheduler, []) | children]
    else
      children
    end
  end

This should work - if you're desperate you can try now. But I think there must be a better way.

Will get back to you.

[zanderxyz]

The issue I raised:
quantum-elixir/quantum-core#385

[zanderxyz]

Hang on, I have a much simpler solution - just steps 3 and 4 above should work for this. I will see if it works on my side first.

[zanderxyz]

Simpler solution doesn't work unfortunately, as swarm still gets started by Quantum. The longer one should though, if you are desperate.

[jc00ke]

Thanks for looking into this @zanderxyz! I'm not that desperate... yet, but would love to figure out a way to gracefully handle this.

[zanderxyz]

@jc00ke Limited traction in my search so far. For now I have pushed an update as v0.2.1 that doesn't start the Veil scheduler in the test environment. Should give a partial, if not full, speedup.

Give it a try and let me know?

[jc00ke]

Yes! Updating and setting config :veil, :environment, Mix.env() shaved off the 5s startup time. Thank you!