@npmcli/git

A utility for spawning git from npm CLI contexts.

This is not an implementation of git itself, it's just a thing that
spawns child processes to tell the system git CLI implementation to do
stuff.

USAGE

 const git = require('@npmcli/git')
git.clone('git://foo/bar.git', 'some-branch', 'some-path', opts) // clone a repo
  .then(() => git.spawn(['checkout', 'some-branch'], {cwd: 'bar'}))
  .then(() => git.spawn(['you get the idea']))

API

Most methods take an options object. Options are described below.

git.spawn(args, opts = {})

Launch a git subprocess with the arguments specified.

All the other functions call this one at some point.

Processes are launched using
@npmcli/promise-spawn, with the
stdioString: true option enabled by default, since git output is
generally in readable string format.

Return value is a Promise that resolves to a result object with {cmd, args, code, signal, stdout, stderr} members, or rejects with an error with
the same fields, passed back from
@npmcli/promise-spawn.

git.clone(repo, ref = 'HEAD', target = null, opts = {}) -> Promise<sha String>

Clone the repository into target path (or the default path for the name
of the repository), checking out ref.

Return value is the sha of the current HEAD in the locally cloned
repository.

In lieu of a specific ref, you may also pass in a spec option, which is
a npm-package-arg object for a git
package dependency reference. In this way, you can select SemVer tags
within a range, or any git committish value. For example:

 const npa = require('npm-package-arg')
git.clone('[email protected]:npm/git.git', '', null, {
  spec: npa('github:npm/git#semver:1.x'),
})

// only gitRange and gitCommittish are relevant, so this works, too
git.clone('[email protected]:npm/git.git', null, null, {
  spec: { gitRange: '1.x' }
})

This will automatically do a shallow --depth=1 clone on any hosts that
are known to support it. To force a shallow or deep clone, you can set the
gitShallow option to true or false respectively.

git.revs(repo, opts = {}) -> Promise<rev doc Object>

Fetch a representation of all of the named references in a given
repository. The resulting doc is intentionally somewhat
packument-like, so that
git semver ranges can be applied using the same
npm-pick-manifest logic.

The resulting object looks like:

 revs = {
  versions: {
    // all semver-looking tags go in here...
    // version: { sha, ref, rawRef, type }
    '1.0.0': {
      sha: '1bc5fba3353f8e1b56493b266bc459276ab23139',
      ref: 'v1.0.0',
      rawRef: 'refs/tags/v1.0.0',
      type: 'tag',
    },
  },
  'dist-tags': {
    HEAD: '1.0.0',
    latest: '1.0.0',
  },
  refs: {
    // all the advertised refs that can be cloned down remotely
    HEAD: { sha, ref, rawRef, type: 'head' },
    master: { ... },
    'v1.0.0': { ... },
    'refs/tags/v1.0.0': { ... },
  },
  shas: {
    // all named shas referenced above
    // sha: [list, of, refs]
    '6b2501f9183a1753027a9bf89a184b7d3d4602c7': [
      'HEAD',
      'master',
      'refs/heads/master',
    ],
    '1bc5fba3353f8e1b56493b266bc459276ab23139': [ 'v1.0.0', 'refs/tags/v1.0.0' ],
  },
}

git.is(opts) -> Promise<Boolean>

Resolve to true if the path argument refers to the root of a git
repository.

It does this by looking for a file in ${path}/.git/index, which is not an
airtight indicator, but at least avoids being fooled by an empty directory
or a file named .git.

git.find(opts) -> Promise<String | null>

Given a path, walk up the file system tree until a git repo working
directory is found. Since this calls stat a bunch of times, it's
probably best to only call it if you're reasonably sure you're likely to be
in a git project somewhere. Pass in opts.root to stop checking at that
directory.

Resolves to null if not in a git project.

git.isClean(opts = {}) -> Promise<Boolean>

Return true if in a git dir, and that git dir is free of changes. This
will resolve true if the git working dir is clean, or false if not, and
reject if the path is not within a git directory or some other error
occurs.

OPTIONS

• retry An object to configure retry behavior for transient network
  errors with exponential backoff.
  • retries: Defaults to opts.fetchRetries or 2
  • factor: Defaults to opts.fetchRetryFactor or 10
  • maxTimeout: Defaults to opts.fetchRetryMaxtimeout or 60000
  • minTimeout: Defaults to opts.fetchRetryMintimeout or 1000
• git Path to the git binary to use. Will look up the first git in
  the PATH if not specified.
• spec The npm-package-arg specifier
  object for the thing being fetched (if relevant).
• fakePlatform set to a fake value of process.platform to use. (Just
  for testing win32 behavior on Unix, and vice versa.)
• cwd The current working dir for the git command. Particularly for
  find and is and isClean, it's good to know that this defaults to
  process.cwd(), as one might expect.
• Any other options that can be passed to
  @npmcli/promise-spawn, or
  child_process.spawn().