Re: Testing What Was Printed

[James E Keenan]

David Cantrell wrote:
Jim Keenan wrote:
Using the standard Test::More framework, is it
possible to test whether what was printed to a
filehandle matches a predetermined string or list of
strings?

Would IO::Capture be of help here?
And here are the fruits of my application of IO::Capture:  a module with 
three subroutines which have proven useful in the project I'm working on 
for my day job.

The full module is here: 
http://mysite.verizon.net/jkeen/perl/modules/misc/TestAuxiliary-0.01.tar.gz

Here is the SYNOPSIS, which includes simple examples of each function:
    use Test::More qw(no_plan);
    use IO::Capture::Stdout;
    use TestAuxiliary qw(
        verify_number_lines
        verify_number_matches
        get_matches
     );
    $capture = IO::Capture::Stdout->new();
    $capture->start();
    print_greek();
    $capture->stop();
    is(verify_number_lines($capture), 4,
        "number of screen lines printed is correct");
    my @week = (
        [ qw| Monday     Lundi    Lunes     | ],
        [ qw| Tuesday    Mardi    Martes    | ],
        [ qw| Wednesday  Mercredi Miercoles | ],
        [ qw| Thursday   Jeudi    Jueves    | ],
        [ qw| Friday     Vendredi Viernes   | ],
        [ qw| Saturday   Samedi   Sabado    | ],
        [ qw| Sunday     Dimanche Domingo   | ],
    );
    $capture->start();
    print_week([EMAIL PROTECTED]);
    $capture->stop();
    my $regex = qr/English:.*?French:.*?Spanish:/s;
    is(verify_number_matches($capture, $regex), 7,
        "correct number of forms printed to screen");
    $regex = qr/French:\s+(.*?)\n/s;
    my @predicted = qw| Lundi Mardi Mercredi Jeudi
        Vendredi Samedi Dimanche |;
    ok(eq_array([EMAIL PROTECTED], get_matches($capture, $regex)),
        "all predicted matches found");
    sub print_greek {
        local $_;
        print "$_\n" for (qw| alpha beta gamma delta |);
        return 1;
    }
    sub print_week {
        my $weekref = shift;
        my @week = @{$weekref};
        for (my $day=0; $day<=$#week; $day++) {
            print "English:  $week[$day][0]\n";
            print "French:   $week[$day][1]\n";
            print "Spanish:  $week[$day][2]\n";
            print "\n";
        }
        return 1;
    }
If you like these, or if you have similar subroutines which can extend 
the functionality of IO::Capture::Stdout, please let me know.  Perhaps 
we can work this up into a full-scale CPAN module or subclass of 
IO::Capture.

Thank you very much.
jimk