Async steps

[oellul]

Just a thought.. what if Cucumber supported the option to run certain steps asynchronously? Take the following scenario:

Given a running game
And 3 players have joined
When player 1 plays 1 round
And player 2 plays 2 rounds
And player 3 plays 3 rounds
Then the leaderboard should look like: ...

In a scenario like this each player does not necessarily need to wait for the others to play their rounds. The ability to make certain steps async could significantly improve test execution time, especially in larger test suites.

[davidjgoss]

I think you could do this today without any changes to Cucumber.

If you think of your step When player {int} plays {int} round(s) as being an action that starts the round(s), but doesn't wait for it/them to finish, you're already most of the way there.

Then the leaderboard should look like: can still do its thing - assert on the outcome.

You need a few other things:

• Something to wait for all the async rounds to finish. This could be a separate explicit step like When all rounds have finished, or could be done quietly early in the existing Then step - I'd tend toward the former for clarity but both are valid. Watch for default timeouts.
• Something to check if there were any errors when running those async rounds, and fail the scenario if there were. See above for where - it could also go in an After hook but if there's been an error you probably want to fail fast rather than go ahead with a doomed assertion.
• Something to manage the scenario-level state. This is probably the "world" depending on your flavour of Cucumber.

I'm mentioning doing and awaiting all this async stuff in a very hand-wavy way, mostly because I don't know your tech stack. But I can see roughly what it looks like in my head in JavaScript for example.

Hope this helps.

[oellul]

Thanks for your suggestion. This looks like a solid approach.

I'm also considering a different approach, a bit less pleasing on the eye in Cucumber terms, but which will help keep all the waits, error handling, etc in a single step. Something like this..

When the following players play rounds concurrently:
  | player | rounds |
  | 1      | 1      |
  | 2      | 2      |
  | 3      | 3      |

[davidjgoss]

Yeah that’s totally valid too