readme.markdown
1# resolve
2
3implements the [node `require.resolve()`
4algorithm](http://nodejs.org/docs/v0.4.8/api/all.html#all_Together...)
5such that you can `require.resolve()` on behalf of a file asynchronously and
6synchronously
7
8[](http://travis-ci.org/substack/node-resolve)
9
10# example
11
12asynchronously resolve:
13
14``` js
15var resolve = require('resolve');
16resolve('tap', { basedir: __dirname }, function (err, res) {
17 if (err) console.error(err)
18 else console.log(res)
19});
20```
21
22```
23$ node example/async.js
24/home/substack/projects/node-resolve/node_modules/tap/lib/main.js
25```
26
27synchronously resolve:
28
29``` js
30var resolve = require('resolve');
31var res = resolve.sync('tap', { basedir: __dirname });
32console.log(res);
33```
34
35```
36$ node example/sync.js
37/home/substack/projects/node-resolve/node_modules/tap/lib/main.js
38```
39
40# methods
41
42``` js
43var resolve = require('resolve')
44```
45
46## resolve(id, opts={}, cb)
47
48Asynchronously resolve the module path string `id` into `cb(err, res [, pkg])`, where `pkg` (if defined) is the data from `package.json`.
49
50options are:
51
52* opts.basedir - directory to begin resolving from
53
54* opts.package - `package.json` data applicable to the module being loaded
55
56* opts.extensions - array of file extensions to search in order
57
58* opts.readFile - how to read files asynchronously
59
60* opts.isFile - function to asynchronously test whether a file exists
61
62* opts.packageFilter - transform the parsed package.json contents before looking
63at the "main" field
64
65* opts.pathFilter(pkg, path, relativePath) - transform a path within a package
66 * pkg - package data
67 * path - the path being resolved
68 * relativePath - the path relative from the package.json location
69 * returns - a relative path that will be joined from the package.json location
70
71* opts.paths - require.paths array to use if nothing is found on the normal
72node_modules recursive walk (probably don't use this)
73
74* opts.moduleDirectory - directory (or directories) in which to recursively look for modules. default: `"node_modules"`
75
76default `opts` values:
77
78``` javascript
79{
80 paths: [],
81 basedir: __dirname,
82 extensions: [ '.js' ],
83 readFile: fs.readFile,
84 isFile: function (file, cb) {
85 fs.stat(file, function (err, stat) {
86 if (err && err.code === 'ENOENT') cb(null, false)
87 else if (err) cb(err)
88 else cb(null, stat.isFile())
89 });
90 },
91 moduleDirectory: 'node_modules'
92}
93```
94
95## resolve.sync(id, opts)
96
97Synchronously resolve the module path string `id`, returning the result and
98throwing an error when `id` can't be resolved.
99
100options are:
101
102* opts.basedir - directory to begin resolving from
103
104* opts.extensions - array of file extensions to search in order
105
106* opts.readFile - how to read files synchronously
107
108* opts.isFile - function to synchronously test whether a file exists
109
110* `opts.packageFilter(pkg, pkgfile)` - transform the parsed package.json
111* contents before looking at the "main" field
112
113* opts.paths - require.paths array to use if nothing is found on the normal
114node_modules recursive walk (probably don't use this)
115
116* opts.moduleDirectory - directory (or directories) in which to recursively look for modules. default: `"node_modules"`
117
118default `opts` values:
119
120``` javascript
121{
122 paths: [],
123 basedir: __dirname,
124 extensions: [ '.js' ],
125 readFileSync: fs.readFileSync,
126 isFile: function (file) {
127 try { return fs.statSync(file).isFile() }
128 catch (e) { return false }
129 },
130 moduleDirectory: 'node_modules'
131}
132````
133
134## resolve.isCore(pkg)
135
136Return whether a package is in core.
137
138# install
139
140With [npm](https://npmjs.org) do:
141
142```
143npm install resolve
144```
145
146# license
147
148MIT
149
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