perl compile test(roughly equivalent 'perl -c')

compile.pl

package Hoge;
our $a = 1;
1;

package main;
use strict;
use warnings;
use Test::More;

our $a = 1;

my $bad_code_string =<<'BAD'
use strict;
use warnings;

BEGIN {
    print "bad begin Hello\n";
    $main::a = 2;
    $Hoge::a = 2;
}

sub hoge {
    pri n t 'Hello';
}
n
1;

BAD
;


my $good_code_string =<<'GOOD'
print "Hello\n";
GOOD
;

=pod check

  influence caller namespace on callee BEGIN/CHECK blocks except %main::.

  all included namespace influence perl internal. perl process stop...
  my $namespace = join ', ', map {'%'.$_} (grep /::$/, keys %main::);

=cut
sub check {
    my $code_str = shift @_ || 'print 1;';
    local (*STDOUT, *STDERR);
    my ($stdout, $stderr) = ('', '');
    open *STDOUT, '>', \$stdout;
    open *STDERR, '>', \$stderr;

    # simple implement for expect %main::
    # local (%main::);
    # my $ret = eval "sub {$code_str}";

    # expect included module. bad failed...
    # my $namespace = join ', ', map {'%'.$_} (grep /::$/, keys %main::);
    my $namespace = '%main::';
    my $code_ref = eval("local ($namespace);".
                   '(sub {my ($tmp) = @_; eval "sub {$tmp}"})->('.
                   "<<'CODE_STR_SEPARATER'
$code_str
CODE_STR_SEPARATER
);");
    my $ret = ($code_ref)? 1: 0;
    unless ($ret) {
        # require Data::Dumper; local $Data::Dumper::Deparse = 1;
        diag(explain((map {"code: $_\n"} split /\n/, $code_str),
                     (map {"stdout: $_\n"} split /\n/, $stdout),
                     (map {"stderr: $_\n"} split /\n/, $stderr),
                     # (map {"deparse: $_\n"} split /\n/, Dumper $code_ref)
                    ));
    }
    $ret;
}

ok (!check($bad_code_string), 'bad code check');
ok (check($good_code_string), 'good code check');
ok ($main::a == 1 && $Hoge::a == 2, 'influence check except %main::')
  or diag("\$main::a: $main::a, \$Hoge::a: $Hoge::a");

done_testing;

あとでコアモジュールのSafeを使ってみるかも