async.js 7.84 KB
Newer Older
liang ce committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229
var core = require('./core');
var fs = require('fs');
var path = require('path');
var caller = require('./caller.js');
var nodeModulesPaths = require('./node-modules-paths.js');
var normalizeOptions = require('./normalize-options.js');

var defaultIsFile = function isFile(file, cb) {
    fs.stat(file, function (err, stat) {
        if (!err) {
            return cb(null, stat.isFile() || stat.isFIFO());
        }
        if (err.code === 'ENOENT' || err.code === 'ENOTDIR') return cb(null, false);
        return cb(err);
    });
};

module.exports = function resolve(x, options, callback) {
    var cb = callback;
    var opts = options;
    if (typeof options === 'function') {
        cb = opts;
        opts = {};
    }
    if (typeof x !== 'string') {
        var err = new TypeError('Path must be a string.');
        return process.nextTick(function () {
            cb(err);
        });
    }

    opts = normalizeOptions(x, opts);

    var isFile = opts.isFile || defaultIsFile;
    var readFile = opts.readFile || fs.readFile;

    var extensions = opts.extensions || ['.js'];
    var basedir = opts.basedir || path.dirname(caller());
    var parent = opts.filename || basedir;

    opts.paths = opts.paths || [];

    // ensure that `basedir` is an absolute path at this point, resolving against the process' current working directory
    var absoluteStart = path.resolve(basedir);

    if (opts.preserveSymlinks === false) {
        fs.realpath(absoluteStart, function (realPathErr, realStart) {
            if (realPathErr && realPathErr.code !== 'ENOENT') cb(err);
            else init(realPathErr ? absoluteStart : realStart);
        });
    } else {
        init(absoluteStart);
    }

    var res;
    function init(basedir) {
        if ((/^(?:\.\.?(?:\/|$)|\/|([A-Za-z]:)?[/\\])/).test(x)) {
            res = path.resolve(basedir, x);
            if (x === '..' || x.slice(-1) === '/') res += '/';
            if ((/\/$/).test(x) && res === basedir) {
                loadAsDirectory(res, opts.package, onfile);
            } else loadAsFile(res, opts.package, onfile);
        } else loadNodeModules(x, basedir, function (err, n, pkg) {
            if (err) cb(err);
            else if (n) cb(null, n, pkg);
            else if (core[x]) return cb(null, x);
            else {
                var moduleError = new Error("Cannot find module '" + x + "' from '" + parent + "'");
                moduleError.code = 'MODULE_NOT_FOUND';
                cb(moduleError);
            }
        });
    }

    function onfile(err, m, pkg) {
        if (err) cb(err);
        else if (m) cb(null, m, pkg);
        else loadAsDirectory(res, function (err, d, pkg) {
            if (err) cb(err);
            else if (d) cb(null, d, pkg);
            else {
                var moduleError = new Error("Cannot find module '" + x + "' from '" + parent + "'");
                moduleError.code = 'MODULE_NOT_FOUND';
                cb(moduleError);
            }
        });
    }

    function loadAsFile(x, thePackage, callback) {
        var loadAsFilePackage = thePackage;
        var cb = callback;
        if (typeof loadAsFilePackage === 'function') {
            cb = loadAsFilePackage;
            loadAsFilePackage = undefined;
        }

        var exts = [''].concat(extensions);
        load(exts, x, loadAsFilePackage);

        function load(exts, x, loadPackage) {
            if (exts.length === 0) return cb(null, undefined, loadPackage);
            var file = x + exts[0];

            var pkg = loadPackage;
            if (pkg) onpkg(null, pkg);
            else loadpkg(path.dirname(file), onpkg);

            function onpkg(err, pkg_, dir) {
                pkg = pkg_;
                if (err) return cb(err);
                if (dir && pkg && opts.pathFilter) {
                    var rfile = path.relative(dir, file);
                    var rel = rfile.slice(0, rfile.length - exts[0].length);
                    var r = opts.pathFilter(pkg, x, rel);
                    if (r) return load(
                        [''].concat(extensions.slice()),
                        path.resolve(dir, r),
                        pkg
                    );
                }
                isFile(file, onex);
            }
            function onex(err, ex) {
                if (err) return cb(err);
                if (ex) return cb(null, file, pkg);
                load(exts.slice(1), x, pkg);
            }
        }
    }

    function loadpkg(dir, cb) {
        if (dir === '' || dir === '/') return cb(null);
        if (process.platform === 'win32' && (/^\w:[/\\]*$/).test(dir)) {
            return cb(null);
        }
        if ((/[/\\]node_modules[/\\]*$/).test(dir)) return cb(null);

        var pkgfile = path.join(dir, 'package.json');
        isFile(pkgfile, function (err, ex) {
            // on err, ex is false
            if (!ex) return loadpkg(path.dirname(dir), cb);

            readFile(pkgfile, function (err, body) {
                if (err) cb(err);
                try { var pkg = JSON.parse(body); } catch (jsonErr) {}

                if (pkg && opts.packageFilter) {
                    pkg = opts.packageFilter(pkg, pkgfile);
                }
                cb(null, pkg, dir);
            });
        });
    }

    function loadAsDirectory(x, loadAsDirectoryPackage, callback) {
        var cb = callback;
        var fpkg = loadAsDirectoryPackage;
        if (typeof fpkg === 'function') {
            cb = fpkg;
            fpkg = opts.package;
        }

        var pkgfile = path.join(x, 'package.json');
        isFile(pkgfile, function (err, ex) {
            if (err) return cb(err);
            if (!ex) return loadAsFile(path.join(x, 'index'), fpkg, cb);

            readFile(pkgfile, function (err, body) {
                if (err) return cb(err);
                try {
                    var pkg = JSON.parse(body);
                } catch (jsonErr) {}

                if (opts.packageFilter) {
                    pkg = opts.packageFilter(pkg, pkgfile);
                }

                if (pkg.main) {
                    if (typeof pkg.main !== 'string') {
                        var mainError = new TypeError('package “' + pkg.name + '” `main` must be a string');
                        mainError.code = 'INVALID_PACKAGE_MAIN';
                        return cb(mainError);
                    }
                    if (pkg.main === '.' || pkg.main === './') {
                        pkg.main = 'index';
                    }
                    loadAsFile(path.resolve(x, pkg.main), pkg, function (err, m, pkg) {
                        if (err) return cb(err);
                        if (m) return cb(null, m, pkg);
                        if (!pkg) return loadAsFile(path.join(x, 'index'), pkg, cb);

                        var dir = path.resolve(x, pkg.main);
                        loadAsDirectory(dir, pkg, function (err, n, pkg) {
                            if (err) return cb(err);
                            if (n) return cb(null, n, pkg);
                            loadAsFile(path.join(x, 'index'), pkg, cb);
                        });
                    });
                    return;
                }

                loadAsFile(path.join(x, '/index'), pkg, cb);
            });
        });
    }

    function processDirs(cb, dirs) {
        if (dirs.length === 0) return cb(null, undefined);
        var dir = dirs[0];

        var file = path.join(dir, x);
        loadAsFile(file, opts.package, onfile);

        function onfile(err, m, pkg) {
            if (err) return cb(err);
            if (m) return cb(null, m, pkg);
            loadAsDirectory(path.join(dir, x), opts.package, ondir);
        }

        function ondir(err, n, pkg) {
            if (err) return cb(err);
            if (n) return cb(null, n, pkg);
            processDirs(cb, dirs.slice(1));
        }
    }
    function loadNodeModules(x, start, cb) {
        processDirs(cb, nodeModulesPaths(start, opts, x));
    }
};