code: function getFileTree () {
    const fileTree = {}
  
    debug('config linterSuffix: %o', linterSuffix)
  
    Object.keys(linterSuffix).forEach(linterName => {
      fileTree[linterName] = []
    })
  
    return fileTree
  }
docs: 获取 fileTree
  
  @returns {object} empty file tree