code: function existsCaseSensitive(filePath) {
      let dirPath = filePath
  
      while (dirPath !== "" && !ROOT.test(dirPath)) {
          const fileName = path.basename(dirPath)
          dirPath = path.dirname(dirPath)
  
          if (fs.readdirSync(dirPath).indexOf(fileName) === -1) {
              return false
          }
      }
  
      return true
  }
docs: Check whether the file exists or not.
  @param {string} filePath The file path to check.
  @returns {boolean} `true` if the file exists.