my $report = do($tree_file) || die "failed to load the report tree\n=> $@\n";

my $is_string = re('^(\s|\w|\d)*$');
my $is_module_name = re('^(([a-zA-Z0-9_]+)\:\:([a-zA-Z0-9_]+))+$');

cmp_deeply(
    $report,
    all(
        isa("ARRAY"), 
        array_each(
            subhashof({
                report_type      => $is_string,
                report_module    => $is_module_name,
                graphing_modules => isa("HASH"),
                question_groups  => all(
                    isa("ARRAY"), 
                    array_each(
                        subhashof({
                            question_group   => $is_string,
                            report_module    => $is_module_name,
                            graphing_modules => isa("HASH"),
                            questions        => all(
                                                isa("ARRAY"),
                                                array_each(re('^\d+$'))
                                                ) # all
                        }) # subhashof
                    ) # array_each
                ) # all
            }) # subhashof
        ) # array_each
    ) # all
); # cmp_deeply