Sending module output to STDOUT in test

[loris]

Dear Monks,

I have a test using Test::More which is failing. I would like to debug the relevant subroutine in my module by inserting a print to see what is going on.

How do can I see the output when I run the test with, say, prove?

Thanks,

loris

[choroba]

When running tests, standard output is used to communicate the test results. You can still use the standard error:

print STDERR "You can see this in prove\n";

Or, don't run your test through prove, but run it directly.

t/01-basic.t

Standard output is not captured in this case.

[Solo]

If you're willing to use STDERR, you'd just need to prove --merge ...

If you really want to send to STDOUT instead of STDERR, you could use something like Test::Trap to capture STDOUT to send to diag().

use Test::More;
use Test::Trap;
 
my @r = trap { some_code(@some_parameters) };
diag($trap->stdout);

[neilwatson]

Try warn instead of print. It's like print STDERR, but prettier and more succinct. You don't want to use STDOUT.

warn "Something went wrong.";

[salva]

Also, Test::More provides a diag sub just for that.

[choroba]

Yes, but... you can use diag in the test file, but not in the library the test file is testing.

[tangent]

For really fine-grained control you might want to check out Log4Perl (I have recently become a convert). There's a tutorial by the author too: Retire your debugger, log smartly with Log::Log4perl

[loris]

Good point. Actually my newer modules all do use Log::Log4Perl, but I happened to have to tweak an old one and was to lazy to set logging up.

Cheers,

loris