More.pm

sub validate_thing { _validate_subtest_wrapper(\&_validate_thing_guts, @_) }
sub validate_class { _validate_subtest_wrapper(\&_validate_class_guts, @_) }
sub validate_role  { _validate_subtest_wrapper(\&_validate_role_guts,  @_) }

sub _validate_subtest_wrapper {
    my ($func, $thing, %args) = @_;

    # note incrementing by 2 because of our upper curried function
    local $Test::Builder::Level = $Test::Builder::Level + 2;

    # run tests w/o a subtest wrapper...
    return $func->($thing => %args)
        unless $args{-subtest};

    # ...or with one.
    return $tb->subtest(delete $args{-subtest} => sub { $func->($thing => %args) });
}