git-pr-get

#!/usr/bin/env ruby
#
# `git pr-get 37` => Fetch Pull Resuest #37 and create branch `pr-37`
# 
# Requirements: 
#   Ruby
#
# Install:
#   $ chmod +x git-pr-get
#   $ mv git-pr-get (somewhere listed in PATH)
#   $ gem i git octokit
#   $ git pr-get     # List open PRs 
#   $ git pr-get 37  # Fetch PR #37 and create branch `pr-37`
#
require 'git'
require 'octokit'
require 'pp'

def error(msg)
  warn "Error: #{msg}"
  exit
end

# Detect github repo from git remote origin
def get_repo(g)
  remote = g.remotes.find{|x| x.name == "origin"}
  if remote.nil?
    error "remote `origin` not found"
  end
  url = remote.url
  if url !~ %r{\Ahttps://github.com/(.*?).git\z}
    error "remote `origin` not a github repo: #{url}"
  end
  return $1
end

def show_pr(pr)
  printf "- #%d %s (by @%s)\n",
    pr[:number], pr[:title], pr[:user][:login]
end

g = Git.open(".")
repo = get_repo(g)

if ARGV.size == 0
  puts "Usage: git pr-get NUMBER"
  # Show existing pull requests
  prs = Octokit.pull_requests(repo, state: "open")
  prs.each{|pr| show_pr(pr)}
else
  # Fetch info about the PR
  n = ARGV[0].to_i
  pr = Octokit.pull_request(repo, n)
  show_pr(pr)

  git_url = pr[:head][:repo][:git_url]
  unless git_url =~ %r{git://github.com/(.*?)/(.*?).git}
    error "could not parse git_url: #{git_url.inspect}"
  end
  owner, name = $1, $2

  # Create remote by author name
  remote = g.remotes.find{|x| x.name == owner}
  unless remote
    clone_url = pr[:head][:repo][:clone_url]
    g.add_remote(owner, clone_url)
    puts "Added remote `#{owner}` (#{clone_url})"
  end

  # Create local PR branch
  remote.fetch
  system "git", "checkout", "-b", "pr-#{n}", pr[:head][:sha]
end