code: function getResultSeverity(messages) {
    if (!messages) {
      return 0;
    }
  
    return messages
      .map(it => it.severity)
      .reduce((maxSeverity, severity) => Math.max(maxSeverity, severity), 0);
  }
docs: Calculates the severity of a eslint.linter.verify result
  @param {Array} messages ESLint's verify() result array
  @see: http://eslint.org/docs/developer-guide/nodejs-api#linter
  
  @returns {Number} accumulatedSeverity The total severity from of the list of results
  0 indicates all-clear
  1 indicates a warning-level result
  > 1 indicates an error-level result