code: function settingsToRegExp(settings, baseRegExp, defaultRegExp) {
          var regExpString = "";
  
          if (settings instanceof Array && settings.length > 0) {
  
              // Append base settings to user settings. The base
              // settings are builtin and cannot be overridden.
              if (baseRegExp) {
                  settings.push("/" + baseRegExp.source + "/");
              }
  
              // convert each string, with optional wildcards to an equivalent
              // string in a regular expression.
              settings.forEach(function (value, index) {
  
                  if (typeof value === "string") {
                      var isRegExp = value[0] === '/' && value[value.length - 1] === '/';
  
                      if (isRegExp) {
                          value = value.substring(1, value.length - 1);
                      } else {
                          value = StringUtils.regexEscape(value);
  
                          // convert user input wildcard, "*" or "?", to a regular
                          // expression. We can just replace the escaped "*" or "?"
                          // since we know it is a wildcard.
                          value = value.replace("\\?", ".?");
                          value = value.replace("\\*", ".*");
  
                          // Add "^" and "$" to prevent matching in the middle of strings.
                          value = "^" + value + "$";
                      }
  
                      if (index > 0) {
                          regExpString += "|";
                      }
  
                      regExpString = regExpString.concat(value);
                  }
              });
          }
  
          if (!regExpString) {
              var defaultParts = [];
              if (baseRegExp) {
                  defaultParts.push(baseRegExp.source);
              }
              if (defaultRegExp) {
                  defaultParts.push(defaultRegExp.source);
              }
              if (defaultParts.length > 0) {
                  regExpString  = defaultParts.join("|");
              } else {
                  return null;
              }
          }
  
          return new RegExp(regExpString);
      }
docs: Convert an array of strings with optional wildcards, to an equivalent
  regular expression.
  
  @param {Array.<string|RegExp>} settings from the file (note: this may be mutated by this function)
  @param {?RegExp} baseRegExp - base regular expression that is always used
  @param {?RegExp} defaultRegExp - additional regular expression that is only used if the user has not configured settings
  @return {RegExp} Regular expression that captures the array of string
  with optional wildcards.