You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

224 lines
5.8 KiB

'use strict'
var BuiltinModule = require('module')
// Guard against poorly mocked module constructors
var Module = module.constructor.length > 1
? module.constructor
: BuiltinModule
var nodePath = require('path')
var modulePaths = []
var moduleAliases = {}
var moduleAliasNames = []
var oldNodeModulePaths = Module._nodeModulePaths
Module._nodeModulePaths = function (from) {
var paths = oldNodeModulePaths.call(this, from)
// Only include the module path for top-level modules
// that were not installed:
if (from.indexOf('node_modules') === -1) {
paths = modulePaths.concat(paths)
}
return paths
}
var oldResolveFilename = Module._resolveFilename
Module._resolveFilename = function (request, parentModule, isMain, options) {
for (var i = moduleAliasNames.length; i-- > 0;) {
var alias = moduleAliasNames[i]
if (isPathMatchesAlias(request, alias)) {
var aliasTarget = moduleAliases[alias]
// Custom function handler
if (typeof moduleAliases[alias] === 'function') {
var fromPath = parentModule.filename
aliasTarget = moduleAliases[alias](fromPath, request, alias)
if (!aliasTarget || typeof aliasTarget !== 'string') {
throw new Error('[module-alias] Expecting custom handler function to return path.')
}
}
request = nodePath.join(aliasTarget, request.substr(alias.length))
// Only use the first match
break
}
}
return oldResolveFilename.call(this, request, parentModule, isMain, options)
}
function isPathMatchesAlias (path, alias) {
// Matching /^alias(\/|$)/
if (path.indexOf(alias) === 0) {
if (path.length === alias.length) return true
if (path[alias.length] === '/') return true
}
return false
}
function addPathHelper (path, targetArray) {
path = nodePath.normalize(path)
if (targetArray && targetArray.indexOf(path) === -1) {
targetArray.unshift(path)
}
}
function removePathHelper (path, targetArray) {
if (targetArray) {
var index = targetArray.indexOf(path)
if (index !== -1) {
targetArray.splice(index, 1)
}
}
}
function addPath (path) {
var parent
path = nodePath.normalize(path)
if (modulePaths.indexOf(path) === -1) {
modulePaths.push(path)
// Enable the search path for the current top-level module
var mainModule = getMainModule()
if (mainModule) {
addPathHelper(path, mainModule.paths)
}
parent = module.parent
// Also modify the paths of the module that was used to load the
// app-module-paths module and all of it's parents
while (parent && parent !== mainModule) {
addPathHelper(path, parent.paths)
parent = parent.parent
}
}
}
function addAliases (aliases) {
for (var alias in aliases) {
addAlias(alias, aliases[alias])
}
}
function addAlias (alias, target) {
moduleAliases[alias] = target
// Cost of sorting is lower here than during resolution
moduleAliasNames = Object.keys(moduleAliases)
moduleAliasNames.sort()
}
/**
* Reset any changes maded (resets all registered aliases
* and custom module directories)
* The function is undocumented and for testing purposes only
*/
function reset () {
var mainModule = getMainModule()
// Reset all changes in paths caused by addPath function
modulePaths.forEach(function (path) {
if (mainModule) {
removePathHelper(path, mainModule.paths)
}
// Delete from require.cache if the module has been required before.
// This is required for node >= 11
Object.getOwnPropertyNames(require.cache).forEach(function (name) {
if (name.indexOf(path) !== -1) {
delete require.cache[name]
}
})
var parent = module.parent
while (parent && parent !== mainModule) {
removePathHelper(path, parent.paths)
parent = parent.parent
}
})
modulePaths = []
moduleAliases = {}
moduleAliasNames = []
}
/**
* Import aliases from package.json
* @param {object} options
*/
function init (options) {
if (typeof options === 'string') {
options = { base: options }
}
options = options || {}
var candidatePackagePaths
if (options.base) {
candidatePackagePaths = [nodePath.resolve(options.base.replace(/\/package\.json$/, ''))]
} else {
// There is probably 99% chance that the project root directory in located
// above the node_modules directory,
// Or that package.json is in the node process' current working directory (when
// running a package manager script, e.g. `yarn start` / `npm run start`)
candidatePackagePaths = [nodePath.join(__dirname, '../..'), process.cwd()]
}
var npmPackage
var base
for (var i in candidatePackagePaths) {
try {
base = candidatePackagePaths[i]
npmPackage = require(nodePath.join(base, 'package.json'))
break
} catch (e) {
// noop
}
}
if (typeof npmPackage !== 'object') {
var pathString = candidatePackagePaths.join(',\n')
throw new Error('Unable to find package.json in any of:\n[' + pathString + ']')
}
//
// Import aliases
//
var aliases = npmPackage._moduleAliases || {}
for (var alias in aliases) {
if (aliases[alias][0] !== '/') {
aliases[alias] = nodePath.join(base, aliases[alias])
}
}
addAliases(aliases)
//
// Register custom module directories (like node_modules)
//
if (npmPackage._moduleDirectories instanceof Array) {
npmPackage._moduleDirectories.forEach(function (dir) {
if (dir === 'node_modules') return
var modulePath = nodePath.join(base, dir)
addPath(modulePath)
})
}
}
function getMainModule () {
return require.main._simulateRepl ? undefined : require.main
}
module.exports = init
module.exports.addPath = addPath
module.exports.addAlias = addAlias
module.exports.addAliases = addAliases
module.exports.isPathMatchesAlias = isPathMatchesAlias
module.exports.reset = reset