Fetch all branches that match a pattern, ideas for API enhancements, and some bugs that were found

It seems that if a branch has a disconnected history from the main branch, isomorphic-git fails to check it out. You can see the problem on this repository:

const git = require('isomorphic-git')
const fs = require('fs')

;(async () => {
  await git.fetch({
    fs,
    dir: 'isogit',
    url: 'https://github.com/isomorphic-git/isomorphic-git.git',
  })

  await git.checkout({
    fs,
    dir: 'isogit',
    remote: 'origin',
    ref: 'gh-pages',
  })
})()

The error reported is:

Failed to read git object with oid e1593a418bbf61846ce6f044bd01c9cd3cde2004

If you change the ref from gh-pages to develop, it works fine.

[wmhilton]

One way is to get a list of branch names in the repository, filter them, then tell fetch to retrieve them.

Another (perhaps alternate) option would be just to have fetch take a collection of include patterns. That’s what I’m essentially doing anyway. Something like: include: [‘v*’, ‘master’].

I’ll probably end up providing both. Some way to do remote reference discovery that essentially exposes GitRemoteHTTP.discover() to get the capabilities and references of a remote, and modifying “git.fetch” to accept an array of refspec patterns. So it’ll probably end up looking a little more verbose, like refspec: ['+refs/heads/master:refs/remotes/origin/master', '+refs/heads/v*:refs/remotes/origin/v/*']. But it will also read the refspecs from .git/config files, which means it’ll understand if you’ve configured your branch to pull from a different remote than ‘origin’ by default, and things like that.

[wmhilton]

A remote option for resolveRef;

Ooh! That’s a great idea. That way listBranches and resolveRef work exactly the same way, and it elevates ‘remote’ to a common abstraction. You won’t have to be aware of the filesystem implementation (refs/remotes/${remote}/branch). And now I see I can fix git.checkout by changing it to checkout local branches by default instead of ‘origin’ by default. (A design flaw on my part that made checking out local branches impossible - oops!)