use FindBin '$Bin'; use lib $Bin; use TestYAML tests => 8; use YAML::XS qw(Dump Load); my $data = { foo => undef }; foreach my $t_data ( $data, Load(Dump($data)) ) { ok( exists($t_data->{foo}), "foo exists" ); is( $t_data->{foo}, undef, "value is undef" ); ok( eval { my $x = \$t_data->{foo}; 1 }, "can reference foo without error" ); is_deeply($t_data, $data, "is deeply"); }