index.js

class FileSystem {
  constructor () {
    this.tree = {}
    this.binaries = {}
  }

  add ({ type, name, path = '/'}) {
    if (! (type && name))
      throw Error('missing required parameters')

    if (!/\/$/.test(path)) path += '/'
    this.tree[ path ] = { type, name, path: path + name }
  }

  move ({ origin, destination }) {
    if (! (origin && destination))
      throw Error('missing required parameters')
    origin = origin.replace(/\/$/, '')
    destination = destination.replace(/\/$/, '')
    let paths = []
    for (let p in this.tree)
      if (-1 != p.indexOf(origin)) paths.push(p)
    paths.forEach(path => {
      const newPath = path.replace(origin, destination)
      this.tree[ newPath ] = this.tree[ path ]
      delete this.tree[ path ]
    })
  }

  write ({ path, content }) {
    if (! (path && content))
      throw Error('missing required parameters')
    this.binaries[ path ] = content
  }

  delete ({ path }) {
    if (! path)
      throw Error('missing required parameters')
    let paths = []
    for (let p in this.tree)
      if (-1 != p.indexOf(path)) paths.push(p)
    paths.forEach(path => {
      delete this.tree[ path ]
      delete this.binaries[ path ]
    })
  }
}

let fs = new FileSystem()

fs.add({ type: 'Drive', name: 'js' })
fs.add({ type: 'Folder', name: 'jquery', path: '/js' })
fs.move({ origin: '/js', destination: '/source' })
fs.add({ type: 'File', name: 'index.js', path: '/js/jquery/' })
fs.write({ path: '/js/jquery/index.js', content: 'console.log("hello world")' })