Introduction

A Crystal library for programatic git interactions. Built over libgit2.

Installation

libgit2

Grits depends on libgit2, specifically libgit2.so.1.3.

This is done to ensure compatibility with libgit2.
The easiest method is probably a build from the libgit2 v1.3.2 release

See the libgit2 quick start for installation steps.

Note

If you want support for the SSH transport, please make sure LIBSSH2 is present when installing libgit2.

Grits

In your shard.yml

dependencies:
  grits:
    gitlab: skinnyjames/grits

and run shards install

Usage

Grits exposes a friendly interface for interacting with git abstractions.

The primary entrypoint is Grits::Repo, but the aim of this shard is to support all libgit2 behaviors.

For instance, interactive with a private remote repository using an ssh key looks like

require "grits"

# create a new clone options
options = Grits::CloneOptions.default

# define an `on_credentials_acquire` callback
options.fetch_options.on_credentials_acquire do |credential|
  credential.add_ssh_key(
    username: credential.username || "git",
    public_key_path: "/path/to/id_rsa.pub",
    private_key_path: "/path/to/id_rsa",
  )
end

dest = "#{__DIR__}/some_folder"

Grits::Repo.clone(
  "git@gitlab.com:<username>/<private_repo>.git", 
  destination, 
  options
) do |repo|
  # interact with the repo..
  # create a new untracked file
  File.write("#{dest}/new.txt", "Hello Grits.\n")

  repo.index do |stage|
    # add the new file to the staging index
    stage.add("new.txt")

    File.open("#{path}/new.txt", "a") do |io|
      io.print "Goodbye.\n"
    end

    # diff the changes
    stage.diff_workdir do |diff|
      changes = diff.lines.map { |line| { line.hunk.header, line.content } }
      puts changes # => [{"@@ -1 +1,2 @@\n", "Hello Grits.\n"}, {"@@ -1 +1,2 @@\n", "Goodbye.\n"}]
    end

    # Write the index to a tree and yield it for commit
    stage.write_tree do |tree|
      repo.commit_at("HEAD") do |parent|
        committer = author = { 
          email: "sean@skinnyjames.net", 
          name: "Sean Gregory", 
          time: Time.utc 
        }

        tree.commit(
          author: author,
          message: "Hello World",
          committer: committer,
          parents: [parent],
          update_ref: "HEAD"
        ) do |commit|
          puts commit.message # => "Hello World"
        end
      end
    end
  end
end