resolve
implements the node require.resolve()
algorithm
such that you can require.resolve() on behalf of a file asynchronously and
synchronously
example
asynchronously resolve:
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:
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
var resolve = require('resolve');
resolve(id, opts={}, cb)
Asynchronously resolve the module path string id into cb(err, res [, pkg]), where pkg (if defined) is the data from package.json.
options are:
- 
opts.basedir - directory to begin resolving from 
- 
opts.package - package.jsondata applicable to the module 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.isDirectory - function to asynchronously test whether a directory exists 
- 
opts.packageFilter(pkg, pkgfile)- transform the parsed package.json contents before looking at the "main" field- pkg - package data
- pkgfile - path to package.json
 
- 
opts.pathFilter(pkg, path, relativePath)- transform a path within a package- pkg - package data
- path - the path being resolved
- relativePath - the path relative from the package.json location
- returns - a relative path that will be joined from the package.json location
 
- 
opts.paths - require.paths array to use if nothing is found on the normal node_modulesrecursive walk (probably don't use this)For advanced users, pathscan also be aopts.paths(request, start, opts)function- request - the import specifier being resolved
- start - lookup path
- getNodeModulesDirs - a thunk (no-argument function) that returns the paths using standard node_modulesresolution
- opts - the resolution options
 
- 
opts.moduleDirectory - directory (or directories) in which to recursively look for modules. default: "node_modules"
- 
opts.preserveSymlinks - if true, doesn't resolve basedirto real path before resolving. This is the way Node resolves dependencies when executed with the --preserve-symlinks flag. Note: this property is currentlytrueby default but it will be changed tofalsein the next major version because Node's resolution algorithm does not preserve symlinks by default.
default opts values:
{
    paths: [],
    basedir: __dirname,
    extensions: ['.js'],
    readFile: fs.readFile,
    isFile: 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);
        });
    },
    isDirectory: function isDirectory(dir, cb) {
        fs.stat(dir, function (err, stat) {
            if (!err) {
                return cb(null, stat.isDirectory());
            }
            if (err.code === 'ENOENT' || err.code === 'ENOTDIR') return cb(null, false);
            return cb(err);
        });
    },
    moduleDirectory: 'node_modules',
    preserveSymlinks: true
}
resolve.sync(id, opts)
Synchronously resolve the module path string id, returning the result and
throwing an error when id 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.isDirectory - function to synchronously test whether a directory exists 
- 
opts.packageFilter(pkg, dir)- transform the parsed package.json contents before looking at the "main" field- pkg - package data
- dir - directory for package.json (Note: the second argument will change to "pkgfile" in v2)
 
- 
opts.pathFilter(pkg, path, relativePath)- transform a path within a package- pkg - package data
- path - the path being resolved
- relativePath - the path relative from the package.json location
- returns - a relative path that will be joined from the package.json location
 
- 
opts.paths - require.paths array to use if nothing is found on the normal node_modulesrecursive walk (probably don't use this)
- 
opts.moduleDirectory - directory (or directories) in which to recursively look for modules. default: "node_modules"
- 
opts.preserveSymlinks - if true, doesn't resolve basedirto real path before resolving. This is the way Node resolves dependencies when executed with the --preserve-symlinks flag. Note: this property is currentlytrueby default but it will be changed tofalsein the next major version because Node's resolution algorithm does not preserve symlinks by default.
default opts values:
{
    paths: [],
    basedir: __dirname,
    extensions: ['.js'],
    readFileSync: fs.readFileSync,
    isFile: function isFile(file) {
        try {
            var stat = fs.statSync(file);
        } catch (e) {
            if (e && (e.code === 'ENOENT' || e.code === 'ENOTDIR')) return false;
            throw e;
        }
        return stat.isFile() || stat.isFIFO();
    },
    isDirectory: function isDirectory(dir) {
        try {
            var stat = fs.statSync(dir);
        } catch (e) {
            if (e && (e.code === 'ENOENT' || e.code === 'ENOTDIR')) return false;
            throw e;
        }
        return stat.isDirectory();
    },
    moduleDirectory: 'node_modules',
    preserveSymlinks: true
}
resolve.isCore(pkg)
Return whether a package is in core.
install
With npm do:
npm install resolve
license
MIT
