void _process_requirements()

in fboss/cli/fboss2/CLI11/App.hpp [2087:2210]

• 100 lines of code
• 48 McCabe index (conditional complexity)

    void _process_requirements() {
        // check excludes
        bool excluded{false};
        std::string excluder;
        for(auto &opt : exclude_options_) {
            if(opt->count() > 0) {
                excluded = true;
                excluder = opt->get_name();
            }
        }
        for(auto &subc : exclude_subcommands_) {
            if(subc->count_all() > 0) {
                excluded = true;
                excluder = subc->get_display_name();
            }
        }
        if(excluded) {
            if(count_all() > 0) {
                throw ExcludesError(get_display_name(), excluder);
            }
            // if we are excluded but didn't receive anything, just return
            return;
        }

        // check excludes
        bool missing_needed{false};
        std::string missing_need;
        for(auto &opt : need_options_) {
            if(opt->count() == 0) {
                missing_needed = true;
                missing_need = opt->get_name();
            }
        }
        for(auto &subc : need_subcommands_) {
            if(subc->count_all() == 0) {
                missing_needed = true;
                missing_need = subc->get_display_name();
            }
        }
        if(missing_needed) {
            if(count_all() > 0) {
                throw RequiresError(get_display_name(), missing_need);
            }
            // if we missing something but didn't have any options, just return
            return;
        }

        std::size_t used_options = 0;
        for(const Option_p &opt : options_) {

            if(opt->count() != 0) {
                ++used_options;
            }
            // Required but empty
            if(opt->get_required() && opt->count() == 0) {
                throw RequiredError(opt->get_name());
            }
            // Requires
            for(const Option *opt_req : opt->needs_)
                if(opt->count() > 0 && opt_req->count() == 0)
                    throw RequiresError(opt->get_name(), opt_req->get_name());
            // Excludes
            for(const Option *opt_ex : opt->excludes_)
                if(opt->count() > 0 && opt_ex->count() != 0)
                    throw ExcludesError(opt->get_name(), opt_ex->get_name());
        }
        // check for the required number of subcommands
        if(require_subcommand_min_ > 0) {
            auto selected_subcommands = get_subcommands();
            if(require_subcommand_min_ > selected_subcommands.size())
                throw RequiredError::Subcommand(require_subcommand_min_);
        }

        // Max error cannot occur, the extra subcommand will parse as an ExtrasError or a remaining item.

        // run this loop to check how many unnamed subcommands were actually used since they are considered options
        // from the perspective of an App
        for(App_p &sub : subcommands_) {
            if(sub->disabled_)
                continue;
            if(sub->name_.empty() && sub->count_all() > 0) {
                ++used_options;
            }
        }

        if(require_option_min_ > used_options || (require_option_max_ > 0 && require_option_max_ < used_options)) {
            auto option_list = detail::join(options_, [](const Option_p &ptr) { return ptr->get_name(false, true); });
            if(option_list.compare(0, 10, "-h,--help,") == 0) {
                option_list.erase(0, 10);
            }
            auto subc_list = get_subcommands([](App *app) { return ((app->get_name().empty()) && (!app->disabled_)); });
            if(!subc_list.empty()) {
                option_list += "," + detail::join(subc_list, [](const App *app) { return app->get_display_name(); });
            }
            throw RequiredError::Option(require_option_min_, require_option_max_, used_options, option_list);
        }

        // now process the requirements for subcommands if needed
        for(App_p &sub : subcommands_) {
            if(sub->disabled_)
                continue;
            if(sub->name_.empty() && sub->required_ == false) {
                if(sub->count_all() == 0) {
                    if(require_option_min_ > 0 && require_option_min_ <= used_options) {
                        continue;
                        // if we have met the requirement and there is nothing in this option group skip checking
                        // requirements
                    }
                    if(require_option_max_ > 0 && used_options >= require_option_min_) {
                        continue;
                        // if we have met the requirement and there is nothing in this option group skip checking
                        // requirements
                    }
                }
            }
            if(sub->count() > 0 || sub->name_.empty()) {
                sub->_process_requirements();
            }

            if(sub->required_ && sub->count_all() == 0) {
                throw(CLI::RequiredError(sub->get_display_name()));
            }
        }
    }