npm-package-arg

Parses package name and specifier passed to commands like npm install or npm cache add, or as found in package.json dependency sections.

EXAMPLES

var assert = require("assert")
var npa = require("npm-package-arg")

// Pass in the descriptor, and it'll return an object
try {
  var parsed = npa("@bar/foo@1.2")
} catch (ex) {
  …
}

USING

var npa = require('npm-package-arg')

var result = npa(arg[, where])

• arg - a string that you might pass to npm install, like: foo@1.2, @bar/foo@1.2, foo@user/foo, http://x.com/foo.tgz, git+https://github.com/user/foo, bitbucket:user/foo, foo.tar.gz, ../foo/bar/ or bar. If the arg you provide doesn't have a specifier part, eg foo then the specifier will default to latest.
• where - Optionally the path to resolve file paths relative to. Defaults to process.cwd()

Throws if the package name is invalid, a dist-tag is invalid or a URL's protocol is not supported.

var result = npa.resolve(name, spec[, where])

• name - The name of the module you want to install. For example: foo or @bar/foo.
• spec - The specifier indicating where and how you can get this module. Something like: 1.2, ^1.7.17, http://x.com/foo.tgz, git+https://github.com/user/foo, bitbucket:user/foo, file:foo.tar.gz or file:../foo/bar/. If not included then the default is latest.
• where - Optionally the path to resolve file paths relative to. Defaults to process.cwd()

Throws if the package name is invalid, a dist-tag is invalid or a URL's protocol is not supported.

var purl = npa.toPurl(arg, reg)

Returns the purl (package URL) form of the given package name/spec.

• arg - A package/version string. For example: foo@1.0.0 or @bar/foo@2.0.0-alpha.1.
• reg - Optionally the URL to the package registry. If not specified, assumes the default https://registry.npmjs.org.

Throws if the package name is invalid, or the supplied arg can't be resolved to a purl.

RESULT OBJECT

The objects that are returned by npm-package-arg contain the following keys:

• type - One of the following strings:
  • git - A git repo
  • tag - A tagged version, like "foo@latest"
  • version - A specific version number, like "foo@1.2.3"
  • range - A version range, like "foo@2.x"
  • file - A local .tar.gz, .tar or .tgz file.
  • directory - A local directory.
  • remote - An http url (presumably to a tgz)
  • alias - A specifier with an alias, like myalias@npm:foo@1.2.3
• registry - If true this specifier refers to a resource hosted on a registry. This is true for tag, version and range types.
• name - If known, the name field expected in the resulting pkg.
• scope - If a name is something like @org/module then the scope field will be set to @org. If it doesn't have a scoped name, then scope is null.
• escapedName - A version of name escaped to match the npm scoped packages specification. Mostly used when making requests against a registry. When name is null, escapedName will also be null.
• rawSpec - The specifier part that was parsed out in calls to npa(arg), or the value of spec in calls to `npa.resolve(name, spec).
• saveSpec - The normalized specifier, for saving to package.json files. null for registry dependencies.
• fetchSpec - The version of the specifier to be used to fetch this resource. null for shortcuts to hosted git dependencies as there isn't just one URL to try with them.
• gitRange - If set, this is a semver specifier to match against git tags with
• gitCommittish - If set, this is the specific committish to use with a git dependency.
• hosted - If from === 'hosted' then this will be a hosted-git-info object. This property is not included when serializing the object as JSON.
• raw - The original un-modified string that was provided. If called as npa.resolve(name, spec) then this will be name + '@' + spec.
• subSpec - If type === 'alias', this is a Result Object for parsing the target specifier for the alias.