Async task is appears to be blocking

[stan-stately]

I'm trying to run a really simple test:

require "async"
describe "async" do
  it "tests async" do
    task = Async do
      sleep(100)
    end
    task.stop
    puts "done"
  end
end

This should return instantly right? why does the test take 100sec to run? i'm sorry if this is really obvious

im on:

• ruby: 3.3.4
• async: 2.21.1
• io-event: 1.7.4

[ioquatix]

A top level async task is blocking as there is no way the sleep can execute while continuing to execute the code outside the event loop.

You should run your entire test inside an event, e.g.

require "async"
describe "async" do
  it "tests async" do
    Async do
      task = Async do
        sleep(100)
      end
      task.stop
      puts "done"
    end
  end
end

If you are using Sus you can use sus-fixtures-async and write it like this:

require "async"
require "sus/fixtures/async"

describe "async" do
  include Sus::Fixtures::Async::ReactorContext
  it "tests async" do
    task = Async do
      sleep(100)
    end
    task.stop
    puts "done"
  end
end

The reactor context also adds a 60s timeout to the code to ensure your tests aren't hanging.

[stan-stately]

I see. i missed that in the docs: When invoked at the top level, will create and run a reactor, and invoke the block as an asynchronous task. Will block until the reactor finishes running.

unrelated but @ioquatix thats literally the fastest non-automated response i've ever seen on github 👏

I really appreciate it