docs: function lintFile (linter, fileName) {
    const fileContents = fs.readFileSync(fileName, {encoding: 'utf8'}).toString()
    const report = linter.validate(fileContents)
    const errors = report.error.count
    const warnings = report.warn.count
  
    if (errors || warnings) {
      this.printFilePath(fileName)
  
      report.error.data.forEach(logItem.bind(this))
      report.warn.data.forEach(logItem.bind(this))
  
      console.log('') // logging empty line
    }
  
    return report
  }