I prefer concise, easily read test cases: 
use Test::More qw(no_plan);

my @items = map {pin()} 1..1000;
my @bad   = grep { ! /\A\d{4}\z/ } @items;
is_deeply(\@bad,[],"All pins are 4 digits");

[download]
BTW - your test case would allow newlines after the digits.

In reply to Re: Testing Random Code by imp
in thread Testing Random Code by Ovid

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