code: function read(fp, opts, fn) {
    opts = opts || {};
    opts.encoding = opts.encoding || 'utf8';
  
    if (opts.read) {
      return opts.read(fp, opts);
    } else if (fn) {
      return fn(fp, opts);
    }
  
    if (endsWith(fp, '.js')) {
      return tryRequire(fp);
    } else {
      var str = tryCatch(fs.readFileSync, fp, opts);
      if (endsWith(fp, '.json')) {
        return tryCatch(JSON.parse, str);
      }
      return str;
    }
  }
docs: Read or require the given file with `opts`