Resolve-alternatus

Implements the node require.resolve() algorithm such that you can require.resolve() on behalf of a file asynchronously and synchronously

Difference between this package and original "resolve":

- /test folder is not published to the npm; as well as /example and some other files
- 'monorepo-symlink-test' renamed

Example

Asynchronously resolve:

``js
var resolve = require('resolve/async'); // or, require('resolve')
resolve('tap', { basedir: __dirname }, function (err, res) {
if (err) console.error(err);
else console.log(res);
});
`

`bash
$ node example/async.js
/home/substack/projects/node-resolve/node_modules/tap/lib/main.js
`

Synchronously resolve:

`js
var resolve = require('resolve/sync'); // or, require('resolve').sync
var res = resolve('tap', { basedir: __dirname });
console.log(res);
``

`bash
$ node example/sync.js
/home/substack/projects/node-resolve/node_modules/tap/lib/main.js
`

$3

`js
var resolve = require('resolve');
var async = require('resolve/async');
var sync = require('resolve/sync');
`

For both the synchronous and asynchronous methods, errors may have any of the following err.code values:

- MODULE_NOT_FOUND: the given path string (id) could not be resolved to a module
- INVALID_BASEDIR: the specified opts.basedir doesn't exist, or is not a directory
- INVALID_PACKAGE_MAIN: a package.json was encountered with an invalid main property (eg. not a string)

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.json data applicable to the module being loaded

- opts.extensions - array of file extensions to search in order

- opts.includeCoreModules - set to false to exclude node core modules (e.g. fs) from the search

- 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 file exists and is a directory

- opts.realpath - function to asynchronously resolve a potential symlink to its real path

- opts.readPackage(readFile, pkgfile, cb) - function to asynchronously read and parse a package.json file
- readFile - the passed opts.readFile or fs.readFile if not specified
- pkgfile - path to package.json
- cb - callback. a SyntaxError error argument will be ignored, all other error arguments will be treated as an error.

- opts.packageFilter(pkg, pkgfile, dir) - transform the parsed package.json contents before looking at the "main" field
- pkg - package data
- pkgfile - path to package.json
- dir - directory that contains 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_modules recursive walk (probably don't use this)

For advanced users, paths can also be a opts.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_modules resolution
- opts - the resolution options

- opts.packageIterator(request, start, opts) - return the list of candidate paths where the packages sources may be found (probably don't use this)
- request - the import specifier being resolved
- start - lookup path
- getPackageCandidates - a thunk (no-argument function) that returns the paths using standard node_modules resolution
- 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 basedir to real path before resolving.
This is the way Node resolves dependencies when executed with the --preserve-symlinks flag.

default opts values:

`js
{
paths: [],
basedir: __dirname,
extensions: ['.js'],
includeCoreModules: true,
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);
});
},
realpath: function realpath(file, cb) {
var realpath = typeof fs.realpath.native === 'function' ? fs.realpath.native : fs.realpath;
realpath(file, function (realPathErr, realPath) {
if (realPathErr && realPathErr.code !== 'ENOENT') cb(realPathErr);
else cb(null, realPathErr ? file : realPath);
});
},
readPackage: function defaultReadPackage(readFile, pkgfile, cb) {
readFile(pkgfile, function (readFileErr, body) {
if (readFileErr) cb(readFileErr);
else {
try {
var pkg = JSON.parse(body);
cb(null, pkg);
} catch (jsonErr) {
cb(jsonErr);
}
}
});
},
moduleDirectory: 'node_modules',
preserveSymlinks: false
}
`

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.includeCoreModules - set to false to exclude node core modules (e.g. fs) from the search

- opts.readFileSync - how to read files synchronously

- opts.isFile - function to synchronously test whether a file exists

- opts.isDirectory - function to synchronously test whether a file exists and is a directory

- opts.realpathSync - function to synchronously resolve a potential symlink to its real path

- opts.readPackageSync(readFileSync, pkgfile) - function to synchronously read and parse a package.json file. a thrown SyntaxError will be ignored, all other exceptions will propagate.
- readFileSync - the passed opts.readFileSync or fs.readFileSync if not specified
- pkgfile - path to package.json

- opts.packageFilter(pkg, pkgfile, dir) - transform the parsed package.json contents before looking at the "main" field
- pkg - package data
- pkgfile - path to package.json
- dir - directory that contains 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_modules recursive walk (probably don't use this)

For advanced users, paths can also be a opts.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_modules resolution
- opts - the resolution options

- opts.packageIterator(request, start, opts) - return the list of candidate paths where the packages sources may be found (probably don't use this)

- request - the import specifier being resolved
- start - lookup path
- getPackageCandidates - a thunk (no-argument function) that returns the paths using standard node_modules resolution
- 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 basedir to real path before resolving.
This is the way Node resolves dependencies when executed with the --preserve-symlinks flag.

default opts values:

`js
{
paths: [],
basedir: __dirname,
extensions: ['.js'],
includeCoreModules: true,
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();
},
realpathSync: function realpathSync(file) {
try {
var realpath = typeof fs.realpathSync.native === 'function' ? fs.realpathSync.native : fs.realpathSync;
return realpath(file);
} catch (realPathErr) {
if (realPathErr.code !== 'ENOENT') {
throw realPathErr;
}
}
return file;
},
readPackageSync: function defaultReadPackageSync(readFileSync, pkgfile) {
return JSON.parse(readFileSync(pkgfile));
},
moduleDirectory: 'node_modules',
preserveSymlinks: false
}
`

Install

With npm do:

`sh
npm install resolve-alternatus
``

License

MIT