1 var core = require('./core');
2 var fs = require('fs');
3 var path = require('path');
4 var caller = require('./caller.js');
5 var nodeModulesPaths = require('./node-modules-paths.js');
6 var splitRe = process.platform === 'win32' ? /[\/\\]/ : /\//;
8 module.exports = function resolve (x, opts, cb) {
9 if (typeof opts === 'function') {
14 if (typeof x !== 'string') {
15 return process.nextTick(function () {
16 cb(new Error('path must be a string'));
20 var isFile = opts.isFile || function (file, cb) {
21 fs.stat(file, function (err, stat) {
22 if (err && err.code === 'ENOENT') cb(null, false)
24 else cb(null, stat.isFile() || stat.isFIFO())
27 var readFile = opts.readFile || fs.readFile;
29 var extensions = opts.extensions || [ '.js' ];
30 var y = opts.basedir || path.dirname(caller());
32 opts.paths = opts.paths || [];
34 if (/^(?:\.\.?(?:\/|$)|\/|([A-Za-z]:)?[\\\/])/.test(x)) {
35 var res = path.resolve(y, x);
36 if (x === '..') res += '/';
37 if (/\/$/.test(x) && res === y) {
38 loadAsDirectory(res, opts.package, onfile);
40 else loadAsFile(res, opts.package, onfile);
42 else loadNodeModules(x, y, function (err, n, pkg) {
44 else if (n) cb(null, n, pkg)
45 else if (core[x]) return cb(null, x);
46 else cb(new Error("Cannot find module '" + x + "' from '" + y + "'"))
49 function onfile (err, m, pkg) {
51 else if (m) cb(null, m, pkg)
52 else loadAsDirectory(res, function (err, d, pkg) {
54 else if (d) cb(null, d, pkg)
55 else cb(new Error("Cannot find module '" + x + "' from '" + y + "'"))
59 function loadAsFile (x, pkg, cb) {
60 if (typeof pkg === 'function') {
65 var exts = [''].concat(extensions);
68 function load (exts, x, pkg) {
69 if (exts.length === 0) return cb(null, undefined, pkg);
70 var file = x + exts[0];
72 if (pkg) onpkg(null, pkg)
73 else loadpkg(path.dirname(file), onpkg);
75 function onpkg (err, pkg_, dir) {
77 if (err) return cb(err)
78 if (dir && pkg && opts.pathFilter) {
79 var rfile = path.relative(dir, file);
80 var rel = rfile.slice(0, rfile.length - exts[0].length);
81 var r = opts.pathFilter(pkg, x, rel);
83 [''].concat(extensions.slice()),
90 function onex (err, ex) {
92 else if (!ex) load(exts.slice(1), x, pkg)
93 else cb(null, file, pkg)
98 function loadpkg (dir, cb) {
99 if (dir === '' || dir === '/') return cb(null);
100 if (process.platform === 'win32' && /^\w:[\\\/]*$/.test(dir)) {
103 if (/[\\\/]node_modules[\\\/]*$/.test(dir)) return cb(null);
105 var pkgfile = path.join(dir, 'package.json');
106 isFile(pkgfile, function (err, ex) {
107 // on err, ex is false
108 if (!ex) return loadpkg(
109 path.dirname(dir), cb
112 readFile(pkgfile, function (err, body) {
114 try { var pkg = JSON.parse(body) }
117 if (pkg && opts.packageFilter) {
118 pkg = opts.packageFilter(pkg, pkgfile);
125 function loadAsDirectory (x, fpkg, cb) {
126 if (typeof fpkg === 'function') {
131 var pkgfile = path.join(x, '/package.json');
132 isFile(pkgfile, function (err, ex) {
133 if (err) return cb(err);
134 if (!ex) return loadAsFile(path.join(x, '/index'), fpkg, cb);
136 readFile(pkgfile, function (err, body) {
137 if (err) return cb(err);
139 var pkg = JSON.parse(body);
143 if (opts.packageFilter) {
144 pkg = opts.packageFilter(pkg, pkgfile);
148 if (pkg.main === '.' || pkg.main === './'){
151 loadAsFile(path.resolve(x, pkg.main), pkg, function (err, m, pkg) {
152 if (err) return cb(err);
153 if (m) return cb(null, m, pkg);
154 if (!pkg) return loadAsFile(path.join(x, '/index'), pkg, cb);
156 var dir = path.resolve(x, pkg.main);
157 loadAsDirectory(dir, pkg, function (err, n, pkg) {
158 if (err) return cb(err);
159 if (n) return cb(null, n, pkg);
160 loadAsFile(path.join(x, '/index'), pkg, cb);
166 loadAsFile(path.join(x, '/index'), pkg, cb);
171 function loadNodeModules (x, start, cb) {
172 (function process (dirs) {
173 if (dirs.length === 0) return cb(null, undefined);
176 var file = path.join(dir, '/', x);
177 loadAsFile(file, undefined, onfile);
179 function onfile (err, m, pkg) {
180 if (err) return cb(err);
181 if (m) return cb(null, m, pkg);
182 loadAsDirectory(path.join(dir, '/', x), undefined, ondir);
185 function ondir (err, n, pkg) {
186 if (err) return cb(err);
187 if (n) return cb(null, n, pkg);
188 process(dirs.slice(1));
190 })(nodeModulesPaths(start, opts));