package abcd;

use strict;
use warnings;
$|++;

sub log {
    my $method = shift;
    my $time = localtime(time);
    my $args = @_
        ? (' ' . join(', ', @_) . ' ')
        : '';
    warn "$time: $method($args)\n";
}

-----------------
# t/001_log.t
#    - verify log() works

use strict;
use warnings;

$|++;

use Test::More;
use IO::Scalar;

plan tests => 4;

my $CLASS = 'abcd';
use_ok( $CLASS );

my $log;
close STDERR;
tie *STDERR, 'IO::Scalar', \$log;

my $ref = \&abcd::log;

$log = '';
$ref->( 'foo' );
like( "$log", qr!^\w{3} \w{3} \d\d \d\d:\d\d:\d\d \d{4}: foo\(\)\n$! );

$log = '';
$ref->( 'foo', 'bar' );
like( "$log", qr!^\w{3} \w{3} \d\d \d\d:\d\d:\d\d \d{4}: foo\( bar \)\n$! );

$log = '';
$ref->( 'foo', 'bar', 'baz' );
like( "$log", qr!^\w{3} \w{3} \d\d \d\d:\d\d:\d\d \d{4}: foo\( bar, baz \)\n$! )
;