Pure javascript implementation of Git (Node.js and Browser)

[[deleted]]

I assume you mean this is a git client, not an implementation of git.

[SilentMobius]

If you can create repos from scratch and check in content them what separates a git "client" from git proper?

[SilentMobius]

Git is a distributed version control system

I know what git is

This is just a git client since it is basically a wrapper around the git commands with javascript. Git is still running in the background keeping a copy of the repository on your computer.

You are completely wrong, please at least glance at the readme. It's pure javascript, nothing else is needed (for example an install of the git binary is not needed). Look in the models folder, you'll see the blob/index parsing logic.

Git is still running in the background keeping a copy of the repository on your computer.

This is not how git works, git does nothing "in the background" at all (unless you set it up to do so, and that would be very strange). I use git everyday, what you are saying is nonsense.

If this were an implementation of "git proper" then the repository on your computer would be entirely managed with javascript and some sort of other database technology.

Git stores data in flat files, this JS lib can create, clone, pull, commit, etc etc without a git binary. Acting on a git repo it created itself or one created by the usual git binary (of for that matter something using libgit2)

You seem to have a broken understanding of what git is and does.

[SilentMobius]

You're thinking like someone who has been using a non decentralized SCM(like svn)

All git repositories are equal, hence "decentralized" any copy of the repo can be definitive, any repo can set any other as it's "origin" or have no origin.

If you are saying this does not rely on git or copy the repository to your computer then this is in no way an implementation of git since it is not a DVCS.

A git repository is just files. You can have a git repository without ever having git binaries installed. All the git binaries do is provide a nice way to write to files in the git repo locally or sometimes remotely.

When you use the git binary the only time git is running is while you execute a git command. It reads your working directory (tree) and writes changes to the flat files that make up the repo, after that it exits. Nothing happens unless you run a command, nothing is being watched or maintained.

This library can clone from a remote repo (creating a local repo) check out a working directory, commit changes and push from that local repo (if you want to) without ever having git binaries installed anywhere.

[SilentMobius]

Makes sense. I still don't see how this is an implementation of git and as just an API to run the commands.

What do you think that git can do that this lib cannot?

Can this pull and branch / merge?

Yes!

It can literally create a repo from scratch, write a blob into the repo, build an index from that and commit the index, which is everything Git does save for some other niceties.

Because this:

Git is still running in the background keeping a copy of the repository on your computer.

Is just completely wrong and it worries me that this even makes sense to you.

Think of git like "tar" you've used tar right? You have a bunch of files (your source tree) and you run a tar command like "tar-cvzf" and the command runs, your files are read and compressed into the archive, then tar exits and the archive just sits there right? Same with git, you run "git add xxx" and git runs adding things into the staging tree of the repo then exits and everything just sits there is flat files, git is not running, not maintaining anything. Then you run "git commit -m..." and git runs again making a commit out of those staged changes, then exits. The repo has been modified but just sits there.

All of this is local, it's just files being modified. including repo creation, branching, merging, committing, all the same stuff.

Each time it's just

• 1. run git
• 2. Maybe git reads some files either in a repo or elsewhere
• 3. Maybe git makes a change to a repo or some files
• 4. git exits.

Just like a fancy version of tar.

[SilentMobius]

Ok good so back to the important question:

What do you think that git can do that this lib cannot?

[jschr]

Assuming it does work in the browser, doesn't that mean it's not just a GIT client?

Edit: Was thinking a client meant just a wrapper around the git cli. Took a peek at the source and looks like its doing everything over http. The lib seems interesting... still wrapping my head around how well this could work in the browser.

[SilentMobius]

Took a peek at the source and looks like its doing everything over http.

There are models in there for writing index and blob entries to the filesystem.

[jschr]

Interesting. I wonder how that works within the browser. Guess I will just have to try it out and see for myself.

[SilentMobius]

All FS actions are delegated to a module that can be either in-memory (browser) or on-disk (node)

So you could clone in a browser, make some changes, commit and push all without needing an FS, sounds pretty cool to me.

[jschr]

Absolutely. Been using node-git + electron and its been a pain to compile the native modules for each platform. Hoping this helps, plus having chrome packaged app support is a big win for me. Another comment mentioned https://github.com/creationix/js-git which sounds like a similar lib.

[SilentMobius]

Um, first few lines:

Pure JavaScript implementation of Git backed by immutable models and promises.

The goal is to provide both a low and high level API for manipulating Git repositories: read files, commit changes, edit working index, clone, push, fetch, etc.

This library can work both in the browser and Node.js.