@webdiscus/pug-loader/src/Filter.js

Pug loader renders Pug files into HTML or compiles them into a template function.

const fs = require('fs');
const path = require('path');
const {
  filterNotFoundException,
  filterLoadException,
  filterInitException,
  loadNodeModuleException,
} = require('./Exeptions');

const filtersPath = path.join(__dirname, 'filters');

class Filter {
  /**
   * Load embedded pug filters.
   *
   * @param {{}} options Loader options.
   */
  static loadFilters(options) {
    if (!options.embedFilters) return;

    if (!options.filters) options.filters = {};

    const embedFilters = options.embedFilters;
    const loadedFilters = options.filters;

    for (const filterName in options.embedFilters) {
      const options = embedFilters[filterName];

      if (options) {
        let filterPath = path.resolve(filtersPath, filterName + '.js');
        let filter;

        try {
          filter = require(filterPath);
        } catch (error) {
          const message = error.toString();
          const posEOL = message.indexOf('\n');
          const messageFirstLine = message.slice(0, posEOL);

          if (messageFirstLine.indexOf('Cannot find module') >= 0) {
            if (messageFirstLine.indexOf(filterPath) > 0) {
              const entries = fs.readdirSync(filtersPath, { withFileTypes: true });
              const files = entries
                .filter((file) => !file.isDirectory())
                .map((file) => path.basename(file.name, '.js'));

              filterNotFoundException(filterName, files.join(', '));
            } else {
              const [, module] = /Cannot find module '(.*?)' from/.exec(messageFirstLine);

              loadNodeModuleException(module);
            }
          }

          filterLoadException(filterName, filterPath, error);
        }

        try {
          // filter module may have the `init(options)` method
          if (filter.init != null) {
            filter.init(options);
          }
          loadedFilters[filterName] = filter.apply.bind(filter);
        } catch (error) {
          filterInitException(filterName, error);
        }
      }
    }
  }
}

module.exports = Filter;