UNPKG

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a package manager for JavaScript

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// check to see if a bin is allowed to be overwritten // either rejects or resolves to nothing. return value not relevant. const isWindows = require('./is-windows.js') const binTarget = require('./bin-target.js') const {resolve, dirname} = require('path') const readCmdShim = require('read-cmd-shim') const fs = require('fs') const {promisify} = require('util') const readlink = promisify(fs.readlink) const checkBin = async ({bin, path, top, global, force}) => { // always ok to clobber when forced // always ok to clobber local bins, or when forced if (force || !global || !top) return // ok, need to make sure, then const target = resolve(binTarget({path, top}), bin) path = resolve(path) return isWindows ? checkShim({target, path}) : checkLink({target, path}) } // only enoent is allowed. anything else is a problem. const handleReadLinkError = async ({er, target}) => er.code === 'ENOENT' ? null : failEEXIST({target}) const checkLink = async ({target, path}) => { const current = await readlink(target) .catch(er => handleReadLinkError({er, target})) if (!current) return const resolved = resolve(dirname(target), current) if (resolved.toLowerCase().indexOf(path.toLowerCase()) !== 0) return failEEXIST({target}) } const handleReadCmdShimError = ({er, target}) => er.code === 'ENOENT' ? null : failEEXIST({target}) const failEEXIST = ({target}) => Promise.reject(Object.assign(new Error('EEXIST: file already exists'), { path: target, code: 'EEXIST', })) const checkShim = async ({target, path}) => { const shims = [ target, target + '.cmd', target + '.ps1', ] await Promise.all(shims.map(async target => { const current = await readCmdShim(target) .catch(er => handleReadCmdShimError({er, target})) if (!current) return const resolved = resolve(dirname(target), current.replace(/\\/g, '/')) if (resolved.toLowerCase().indexOf(path.toLowerCase()) !== 0) return failEEXIST({target}) })) } module.exports = checkBin