npm
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
const assert = require("assert")
const npa = require("npm-package-arg")
// Pass in the descriptor, and it'll return an object
try {
const parsed = npa("@bar/foo@1.2")
} catch (ex) {
…
}USING
const npa = require('npm-package-arg')
const 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/orbar. If the arg you provide doesn't have a specifier part, egfoothen the specifier will default tolatest. - 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.
const result = npa.resolve(name, spec[, where])
- name - The name of the module you want to install. For example:
fooor@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.gzorfile:../foo/bar/. If not included then the default islatest. - 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.
const 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 repotag- 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,.taror.tgzfile.directory- A local directory.remote- An http url (presumably to a tgz)alias- A specifier with an alias, likemyalias@npm:foo@1.2.3
registry- If true this specifier refers to a resource hosted on a registry. This is true fortag,versionandrangetypes.name- If known, thenamefield expected in the resulting pkg.scope- If a name is something like@org/modulethen thescopefield will be set to@org. If it doesn't have a scoped name, then scope isnull.escapedName- A version ofnameescaped to match the npm scoped packages specification. Mostly used when making requests against a registry. Whennameisnull,escapedNamewill also benull.rawSpec- The specifier part that was parsed out in calls tonpa(arg), or the value ofspecin calls tonpa.resolve(name, spec).saveSpec- The normalized specifier, for saving to package.json files.nullfor registry dependencies. See note below about how this is (not) encoded.fetchSpec- The version of the specifier to be used to fetch this resource.nullfor 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 withgitCommittish- If set, this is the specific committish to use with a git dependency.hosted- Iffrom === 'hosted'then this will be ahosted-git-infoobject. This property is not included when serializing the object as JSON.raw- The original un-modified string that was provided. If called asnpa.resolve(name, spec)then this will bename + '@' + spec.subSpec- Iftype === 'alias', this is a Result Object for parsing the target specifier for the alias.
SAVE SPECS
TLDR: file: urls are NOT uri encoded.
Historically, npm would uri decode file package args, but did not do any uri encoding for the saveSpec. This meant that it generated incorrect saveSpecs for directories with characters that looked like encoded uri characters, and also that it could not parse directories with some unencoded uri characters (such as %).
In order to fix this, and to not break all existing versions of npm, this module now parses all file package args as not being uri encoded. And in order to not break all of the package.json files npm has made in the past, it also does not uri encode the saveSpec. This includes package args that start with file:. This does mean that npm file: package args are not RFC compliant, and making them so constitutes quite a breaking change.