react / react-0.13.3 / examples / basic-commonjs / node_modules / browserify / node_modules / resolve / readme.markdown
84578 views# resolve
implements the [node `require.resolve()`
algorithm](http://nodejs.org/docs/v0.4.8/api/all.html#all_Together...)
such that you can `require.resolve()` on behalf of a file asynchronously and
synchronously
[](http://travis-ci.org/substack/node-resolve)
# example
asynchronously resolve:
``` js
var resolve = require('resolve');
resolve('tap', { basedir: __dirname }, function (err, res) {
    if (err) console.error(err)
    else console.log(res)
});
```
```
$ node example/async.js
/home/substack/projects/node-resolve/node_modules/tap/lib/main.js
```
synchronously resolve:
``` js
var resolve = require('resolve');
var res = resolve.sync('tap', { basedir: __dirname });
console.log(res);
```
```
$ node example/sync.js
/home/substack/projects/node-resolve/node_modules/tap/lib/main.js
```
# methods
``` js
var resolve = require('resolve')
```
## resolve(pkg, opts={}, cb)
Asynchronously resolve the module path string `pkg` into `cb(err, res)`.
options are:
* opts.basedir - directory to begin resolving from
* opts.package - package from which module is being loaded
* opts.extensions - array of file extensions to search in order
* opts.readFile - how to read files asynchronously
* opts.isFile - function to asynchronously test whether a file exists
* opts.packageFilter - transform the parsed package.json contents before looking
at the "main" field
* opts.paths - require.paths array to use if nothing is found on the normal
node_modules recursive walk (probably don't use this)
* opts.moduleDirectory - directory (or directories) to recursively look for modules in. default:
`"node_modules"`
default `opts` values:
``` javascript
{
    paths: [],
    basedir: __dirname,
    extensions: [ '.js' ],
    readFile: fs.readFile,
    isFile: function (file, cb) {
        fs.stat(file, function (err, stat) {
            if (err && err.code === 'ENOENT') cb(null, false)
            else if (err) cb(err)
            else cb(null, stat.isFile())
        });
    },
    moduleDirectory: 'node_modules'
}
```
## resolve.sync(pkg, opts)
Synchronously resolve the module path string `pkg`, returning the result and
throwing an error when `pkg` can't be resolved.
options are:
* opts.basedir - directory to begin resolving from
* opts.extensions - array of file extensions to search in order
* opts.readFile - how to read files synchronously
* opts.isFile - function to synchronously test whether a file exists
* opts.packageFilter - transform the parsed package.json contents before looking
at the "main" field
* opts.paths - require.paths array to use if nothing is found on the normal
node_modules recursive walk (probably don't use this)
* opts.moduleDirectory - directory (or directories) to recursively look for modules in. default:
`"node_modules"`
default `opts` values:
``` javascript
{
    paths: [],
    basedir: __dirname,
    extensions: [ '.js' ],
    readFileSync: fs.readFileSync,
    isFile: function (file) {
        try { return fs.statSync(file).isFile() }
        catch (e) { return false }
    },
    moduleDirectory: 'node_modules'
}
````
## resolve.isCore(pkg)
Return whether a package is in core.
# install
With [npm](https://npmjs.org) do:
```
npm install resolve
```
# license
MIT