File Explorer

1const { resolve, dirname, sep } = require('path')2const { lstat } = require('fs/promises')3const throwNonEnoent = er => {4  if (er.code !== 'ENOENT') {5    throw er6  }7}8 9const cmdShim = require('cmd-shim')10const readCmdShim = require('read-cmd-shim')11 12const fixBin = require('./fix-bin.js')13 14// even in --force mode, we never create a shim over a shim we've15// already created.  you can have multiple packages in a tree trying16// to contend for the same bin, which creates a race condition and17// nondeterminism.18const seen = new Set()19 20const failEEXIST = ({ to, from }) =>21  Promise.reject(Object.assign(new Error('EEXIST: file already exists'), {22    path: to,23    dest: from,24    code: 'EEXIST',25  }))26 27const handleReadCmdShimError = ({ er, from, to }) =>28  er.code === 'ENOENT' ? null29  : er.code === 'ENOTASHIM' ? failEEXIST({ from, to })30  : Promise.reject(er)31 32const SKIP = Symbol('skip - missing or already installed')33const shimBin = ({ path, to, from, absFrom, force }) => {34  const shims = [35    to,36    to + '.cmd',37    to + '.ps1',38  ]39 40  for (const shim of shims) {41    if (seen.has(shim)) {42      return true43    }44    seen.add(shim)45  }46 47  return Promise.all([48    ...shims,49    absFrom,50  ].map(f => lstat(f).catch(throwNonEnoent))).then((stats) => {51    const [, , , stFrom] = stats52    if (!stFrom) {53      return SKIP54    }55 56    if (force) {57      return false58    }59 60    return Promise.all(shims.map((s, i) => [s, stats[i]]).map(([s, st]) => {61      if (!st) {62        return false63      }64      return readCmdShim(s)65        .then(target => {66          target = resolve(dirname(to), target)67          const base = resolve(path)68          if (target !== base && !target.startsWith(base + sep)) {69            return failEEXIST({ from, to, path })70          }71          return false72        }, er => handleReadCmdShimError({ er, from, to }))73    }))74  })75    .then(skip => skip !== SKIP && doShim(absFrom, to))76}77 78const doShim = (absFrom, to) =>79  cmdShim(absFrom, to).then(() => fixBin(absFrom))80 81const resetSeen = () => {82  for (const p of seen) {83    seen.delete(p)84  }85}86 87module.exports = Object.assign(shimBin, { resetSeen })88