Fix problem with defining rules

[KES777]

Fixes: #75

I suppose problem is here:
https://github.com/Perl-Toolchain-Gang/Test-Harness/blob/master/lib/App/Prove.pm#L371-L383

This code returns:

  rules => {
    par => [
      {
        seq => xx/start.t,
      },
      xx/t*,
      {
        seq => xx/finish.t,
      },
    ],
  },

For prove --jobs=5 xx/*.t --rules='seq=xx/start.t' --rules='par=xx/t*' --rules='seq=xx/finish.t command.

Though I am ok that tests are run in parallel by default. This line of code $args{rules} = { par => [@rules] }; breaks this state in documentation:

The option may be specified multiple times, and the order matters.

https://metacpan.org/dist/Test-Harness/view/bin/prove#-rules

Solution

With this fix I am able to achieve this behavior: https://perldoc.perl.org/TAP::Parser::Scheduler#Rules-examples

# Run some  startup tests in sequence, then some parallel tests then some
# teardown tests in sequence.
{
    seq => [
        { seq => 't/startup/*.t' },
        { par => ['t/a/*.t','t/b/*.t','t/c/*.t'], }
        { seq => 't/shutdown/*.t' },
    ],
},

For prove --jobs=5 xx/*.t --rules='seq=xx/start.t' --rules='par=xx/t*' --rules='seq=xx/finish.t command when options are read the structure look correct:

DBG> $args{rules}
{
  seq => [
    {
      seq => xx/start.t,
    },
    {
      par => xx/t*,
    },
    {
      seq => xx/finish.t,
    },
  ],
}

And the test t/start.t run before everything, xx/t* in parallel after it. When finished the t/finish.t is run.

[Leont]

I think this makes sense. I have to double-check if there aren't any use-cases that would break with this change but if so they aren't immediately obvious to me.