302 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Markdown
		
	
	
		
		
			
		
	
	
			302 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Markdown
		
	
	
|  | # resolve <sup>[![Version Badge][2]][1]</sup>
 | ||
|  | 
 | ||
|  | implements the [node `require.resolve()` algorithm](https://nodejs.org/api/modules.html#modules_all_together) such that you can `require.resolve()` on behalf of a file asynchronously and synchronously | ||
|  | 
 | ||
|  | [![github actions][actions-image]][actions-url] | ||
|  | [![coverage][codecov-image]][codecov-url] | ||
|  | [![dependency status][5]][6] | ||
|  | [![dev dependency status][7]][8] | ||
|  | [![License][license-image]][license-url] | ||
|  | [![Downloads][downloads-image]][downloads-url] | ||
|  | 
 | ||
|  | [![npm badge][11]][1] | ||
|  | 
 | ||
|  | # 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); | ||
|  | }); | ||
|  | ``` | ||
|  | 
 | ||
|  | ``` | ||
|  | $ 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); | ||
|  | ``` | ||
|  | 
 | ||
|  | ``` | ||
|  | $ node example/sync.js | ||
|  | /home/substack/projects/node-resolve/node_modules/tap/lib/main.js | ||
|  | ``` | ||
|  | 
 | ||
|  | # methods
 | ||
|  | 
 | ||
|  | ```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 | ||
|  | 
 | ||
|  | * `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](https://nodejs.org/api/all.html#cli_preserve_symlinks) flag. | ||
|  | **Note:** this property is currently `true` by default but it will be changed to | ||
|  | `false` in the next major version because *Node's resolution algorithm does not preserve symlinks by default*. | ||
|  | 
 | ||
|  | 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(null); | ||
|  |                 } | ||
|  |             } | ||
|  |         }); | ||
|  |     }, | ||
|  |     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.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 | ||
|  |   * readFileSync - the passed `opts.readFileSync` or `fs.readFileSync` if not specified | ||
|  |   * pkgfile - path to package.json | ||
|  | 
 | ||
|  | * `opts.packageFilter(pkg, dir)` - transform the parsed package.json contents before looking at the "main" field | ||
|  |   * pkg - package data | ||
|  |   * dir - directory that contains 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_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](https://nodejs.org/api/all.html#cli_preserve_symlinks) flag. | ||
|  | **Note:** this property is currently `true` by default but it will be changed to | ||
|  | `false` in the next major version because *Node's resolution algorithm does not preserve symlinks by default*. | ||
|  | 
 | ||
|  | 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) { | ||
|  |         var body = readFileSync(pkgfile); | ||
|  |         try { | ||
|  |             var pkg = JSON.parse(body); | ||
|  |             return pkg; | ||
|  |         } catch (jsonErr) {} | ||
|  |     }, | ||
|  |     moduleDirectory: 'node_modules', | ||
|  |     preserveSymlinks: true | ||
|  | } | ||
|  | ``` | ||
|  | 
 | ||
|  | # install
 | ||
|  | 
 | ||
|  | With [npm](https://npmjs.org) do: | ||
|  | 
 | ||
|  | ```sh | ||
|  | npm install resolve | ||
|  | ``` | ||
|  | 
 | ||
|  | # license
 | ||
|  | 
 | ||
|  | MIT | ||
|  | 
 | ||
|  | [1]: https://npmjs.org/package/resolve | ||
|  | [2]: https://versionbadg.es/browserify/resolve.svg | ||
|  | [5]: https://david-dm.org/browserify/resolve.svg | ||
|  | [6]: https://david-dm.org/browserify/resolve | ||
|  | [7]: https://david-dm.org/browserify/resolve/dev-status.svg | ||
|  | [8]: https://david-dm.org/browserify/resolve#info=devDependencies | ||
|  | [11]: https://nodei.co/npm/resolve.png?downloads=true&stars=true | ||
|  | [license-image]: https://img.shields.io/npm/l/resolve.svg | ||
|  | [license-url]: LICENSE | ||
|  | [downloads-image]: https://img.shields.io/npm/dm/resolve.svg | ||
|  | [downloads-url]: https://npm-stat.com/charts.html?package=resolve | ||
|  | [codecov-image]: https://codecov.io/gh/browserify/resolve/branch/main/graphs/badge.svg | ||
|  | [codecov-url]: https://app.codecov.io/gh/browserify/resolve/ | ||
|  | [actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/browserify/resolve | ||
|  | [actions-url]: https://github.com/browserify/resolve/actions |