isomorphic-git

What is isomorphic-git?

isomorphic-git is a pure JavaScript implementation of Git that works in both Node.js and browser environments. It provides a wide range of Git functionalities, allowing developers to perform Git operations without relying on native Git installations.

What are isomorphic-git's main functionalities?

Clone a Repository

This feature allows you to clone a Git repository. The code sample demonstrates how to clone the isomorphic-git repository into a local directory named '/tutorial'.

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

(async () => {
  await git.clone({
    fs,
    dir: '/tutorial',
    url: 'https://github.com/isomorphic-git/isomorphic-git',
    singleBranch: true,
    depth: 1
  });
  console.log('Cloned the repository!');
})();

Commit Changes

This feature allows you to commit changes to a repository. The code sample demonstrates how to commit changes in the '/tutorial' directory with a commit message 'Initial commit'.

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

(async () => {
  await git.commit({
    fs,
    dir: '/tutorial',
    author: {
      name: 'Your Name',
      email: '[e-mail]'
    },
    message: 'Initial commit'
  });
  console.log('Committed changes!');
})();

Push to Remote

This feature allows you to push changes to a remote repository. The code sample demonstrates how to push changes from the '/tutorial' directory to the 'main' branch of the remote repository 'origin'.

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

(async () => {
  await git.push({
    fs,
    dir: '/tutorial',
    remote: 'origin',
    ref: 'main',
    token: 'your-github-token'
  });
  console.log('Pushed to remote!');
})();

Fetch from Remote

This feature allows you to fetch changes from a remote repository. The code sample demonstrates how to fetch changes from the 'origin' remote repository into the '/tutorial' directory.

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

(async () => {
  await git.fetch({
    fs,
    dir: '/tutorial',
    remote: 'origin'
  });
  console.log('Fetched from remote!');
})();

List Files in a Commit

This feature allows you to list files in a specific commit. The code sample demonstrates how to read the commit object for the 'HEAD' commit and log the tree of files.

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

(async () => {
  const commit = await git.readCommit({
    fs,
    dir: '/tutorial',
    oid: 'HEAD'
  });
  console.log(commit.commit.tree);
})();

Other packages similar to isomorphic-git

nodegit

NodeGit is a native Node.js binding to the libgit2 library, providing a comprehensive set of Git functionalities. Unlike isomorphic-git, NodeGit relies on native bindings and is not designed to work in browser environments.

simple-git

Simple-git is a lightweight wrapper around the Git command line interface, providing a simple API for common Git operations. It requires Git to be installed on the system and is not designed to work in browser environments, unlike isomorphic-git.

dugite

Dugite provides a simplified interface for using Git in Node.js applications. It bundles a specific version of Git with the package, ensuring consistent behavior across different environments. However, it does not support browser environments like isomorphic-git.

README

isomorphic-git

JavaScript library for interacting with git repositories, circa 2017

(Originally I was going to call it esgit but the name is too similar to another project called es-git.)

Progress

Porcelain:

• git clone
  • git init
  • git config
  • git fetch (due to CORS, use https://cors-anywhere.herokuapp.com/https://github.com instead of https://github.com)
    • ref-deltas
    • ofs-deltas
  • git checkout
    • update index SHA correctly
• git list (ls-files)
• git add
• git remove
• git status
• git commit
• git push (due to CORS, use https://cors-anywhere.herokuapp.com/https://github.com instead of https://github.com)
• git tag
• git diff
• git merge
• esgit CLI

Plumbing:

• read-tree
• git listCommits (rev-list)
• git pack (pack-objects)
• git list packed objects (verify-pack)
• git unpack-objects

Note: There appears to be no a way to push signed commits back to Github using their API (v3 or v4), so I think we will have to use smart HTTP, packfiles, and an anti-CORS proxy.

High-level API (unstable)

This is analogous to the "porcelain" git commands. There is a single function git() that serves as a fluent command builder.

Examples:

import git from 'isomorphic-git'

// Clone a repository
git('.')
  .depth(1)
  .branch('master')
  .clone('https://cors-anywhere.herokuapp.com/https://github.com/wmhilton/isomorphic-git')

// Setup an new repository
git('.').init()

// Manually add a remote
git('.')
  .setConfig('remote.origin.url', 'https://cors-anywhere.herokuapp.com/https://github.com/wmhilton/isomorphic-git')

// Fetch the latest commit using a shallow clone
git('.')
  .remote('origin')
  .depth(1)
  .fetch('refs/heads/master')

// Checkout a commitish
git('.').checkout('master')

// List files in the index
git('.').list()

// Add files to the index
git('.').add('README.md')

// Remove files from the index
git('.').remove('.env')

// Create a new commit (there's actually several more options for date, committer)
git('.')
  .add('a.txt')
  .author('Mr. Test')
  .email('[e-mail]')
  .signingKey('-----BEGIN PGP PRIVATE KEY BLOCK-----...')
  .commit('Added the a.txt file')

// Push a branch back to Github
git('.')
  .githubToken(process.env.GITHUB_TOKEN)
  .remote('origin')
  .push('refs/heads/master')

// TODO: git.merge(), git.pull(), git.status(), git.diff(), git.tag(), git.branch(), etc

// And if you need to work with bare repos there are
// equivalents to the `--git-dir` and `--work-tree` options
git().gitdir('my-bare-repo').workdir('/var/www/website')

CLI

I realized I could "translate" command line options into JavaScript chained commands without hard-coding any knowledge of the API if I kept the chained commands very predictable. I built a purely a generic translator and it worked surprisingly well. So you can do any current or future isomorphic-git commands using the included esgit CLI. It always starts with an implicit git('.') so it defaults to working in the current working directory.

// Create a new empty repo
esgit --gitdir=test init

// Clone from a Github repository to the current working directory.
// Just like it's counterpart, clone is really just shorthand for git.init(); git.fetch(); git.checkout();
esgit clone https://github.com/wmhilton/isomorphic-git

// Checkout a commitish
esgit checkout master

// List files in the index
esgit list

// Add files to the index
esgit add README.md

// Remove files from the index
esgit remove .env

// Create a new commit (there's actually several more options for date, committer)
esgit add a.txt
esgit --author='Mr. Test' --email=[e-mail] --signingKey="$(cat private.key)" commit 'Added the a.txt file'

// And if you need to work with bare repos there are
// equivalents to the `--git-dir` and `--work-tree` options
esgit --gitdir=my-bare-repo --workdir=/var/www/website

Low-level API (also unstable)

The high-level makes some assumptions (like you have a file-system and network access) that might not be well suited to your embedded git-based concept thingy. Fear not! I am purposefully building this library as a series of small modules so you can pick and choose features as you need them.

Commands

import * as managers from 'isomorphic-git/src/commands'

Each command is available as its own file, so hopefully with a bit of finagling you will be able to import individual commands if you only need a few and can benefit from tree-shaking.

Managers

import * as managers from 'isomorphic-git/src/managers'

Managers are a level above models. They take care of implementation performance details like

• batching reads to and from the file system
• in-process concurrency locks
• lockfiles
• caching files and invalidating cached results
• reusing objects
• object memory pools

Models

import * as models from 'isomorphic-git/src/models'

Models are the lowest level building blocks. They generally have very few or no dependencies except for 'buffer'. This makes them portable to many different environments so they can be a useful lowest common denominator.

Utils

import * as utils from 'isomorphic-git/src/utils'

I lied. Utils are actually the lowest level building blocks.