Async::Notification has trouble when signalling with a plain hash object

[tadman]

The keyword argument causes the hash to be interpreted incorrectly by Ruby:

require 'async'
require 'async/notification'

Async do
  notification = Async::Notification.new

  hash = {
    async: true
  }

  notification.signal(hash)
  # => ArgumentError: unknown keyword: :async
end

It may be better to go all keyword args, like signal(value:, task:) to avoid ambiguity here, though that would be a breaking change.

[ioquatix]

This will be fixed in Ruby 3 and is just an unfortunate issue of Ruby 2.x - I'll see if there is anything we can do to fix this, but I've run into this issue before with other libraries. It's one of the motivating factors to remove the implicit conversion of a hash to options.

[ioquatix]

Matz has confirmed the decision for Ruby 3.0 however it might be possible to work on 2.x by using empty options, **{}.

notification.signal(hash, **{})

This should be backwards and forwards compatible.