Plugin API for greater speed

[aslakhellesoy]

Using Aruba to test a CLI with somewhat slow startup incurs a slow suite of scenarios. For example, this is true for JRuby-based CLIs. This includes Cucumber itself.

Aruba has well-known inputs and outputs:

• command
• command line arguments
• STDIN
• STDOUT
• STDERR
• exit status

We could make this a contract:

class Driver
  def run(cmd, args, stdin, stdout, stderr)
    # run it all
    return status
  end
end

Aruba would ship with a default driver, which forks a process like it currently does

However, people could supply their own driver following the same contract, which would be custom for the app under test, and would run it in the same ruby process.

I got this idea from cucumber/common#432 where @mattwynne and @os97673 were discussing a slow test suite for Cucumber on JRuby.

[mattwynne]

I like this. Like a Rack adapter but for console apps.

@tooky @os97673 this could help speed up Cucumber's test suite a lot.

[os97673]

@mattwynne I've noticed this ticket but postponed it in my list since to make it useful for us I need to figure out how to run JRuby program inside the same JVM (not sure if this is possible). This will take some time for me thus I'm concentrating on 1.3.0 now.

[aslakhellesoy]

@os97673 the whole point of this feature is that we wouldn't have to launch a new (j)ruby interpreter from the command line at all. We'd just call some sort of main method within the same ruby process as the one aruba is running in.

[os97673]

I see. So the purpose is even more radical change than I have expected :) Need to think about it.

[aslakhellesoy]

Fixed in 0.5.2!