Test::Time

Use Test::Scheduler to use on your tests, not only Promises, but sleep, now and time.

    my $started = now;
    $*SCHEDULER = mock-time :auto-advance;

    sleep 10;
    say "did it passed { now - $started } seconds?";
    unmock-time;

    say "No, just passed { now - $started } seconds!";

    #`{{{
    Output:
        did it passed 10.0016178 seconds?
        No, just passed 0.07388266 seconds!
    }}}

Or you can use $*SCHEDULER.advance-by: 10 as you would when using Test::Scheduler