G'day tizatron,

Given that you're really just testing output from your script, Test::Output seems like a good choice; however, although you've loaded that module, you haven't used any of its functionality.

When I read "return $heredoc;", I wondered what this was for (it seemed pointless). I do see that you've questioned this yourself: "I had to add a return() to the usage function to get that test to pass ...". If your tests identify logic errors (or similar) in the code you're testing, then do fix the code; however, don't add questionable code just to make the tests pass.

Here's an example of how you might go about interspersing Test::More and Test::Output tests.

Sample production script (pm_script_testing.pl):

#!/usr/bin/env perl

use strict;
use warnings;

usage() unless @ARGV;

print scalar(@ARGV), ": @ARGV\n";

sub usage {
    warn "Argument required!\n";
    exit;
}
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Sample test script (pm_script_testing.t):

#!/usr/bin/env perl

use strict;
use warnings;

use Test::More tests => 4;
use Test::Output;

stderr_is { qx{perl -c pm_script_testing.pl} }
            "pm_script_testing.pl syntax OK\n", 'Test Syntax';

stderr_is { qx{pm_script_testing.pl} }
            "Argument required!\n", 'Test Zero Arguments';
            
is(qx{pm_script_testing.pl 123}, "1: 123\n", 'Test One Argument');

stdout_is { system qw{pm_script_testing.pl 123 qwe} }
            "2: 123 qwe\n", 'Test Two Arguments';
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Output:

$ pm_script_testing.t
1..4
ok 1 - Test Syntax
ok 2 - Test Zero Arguments
ok 3 - Test One Argument
ok 4 - Test Two Arguments
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If you haven't done so already, you may benefit from reading Test::Tutorial.