perl.p6

unit module Test::Output;

my class IO::Capture::Single is IO::Handle {
    has @.contents;
    method print (*@what) { @.contents.push: @what.join: ''; }
    method print-nl       { self.print($.nl-out);            }
    method Str (*@what)   { return @.contents.join: '';      }
}

sub output-is (&code, Regex $expected, $test-name = 'output matches' )
    is export
{
    my $out = IO::Capture::Single.new;
    my $err = IO::Capture::Single.new;
    {
        my $*OUT = $out;
        my $*ERR = $err;
        &code();
    }
    say "Output is $out";
    say "STDERR is $err";

    return :out(~$out), :err(~$err);
}