Simple integration branching with octokit

integration_branch.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'bundler/setup'
require 'octokit'

class IntegrationBranch
  def self.user
    ENV['GITHUB_USER'] || ENV['USER']
  end

  def self.token
    ENV['GITHUB_API_TOKEN'] || fail("Please set a GITHUB_API_TOKEN")
  end

  def self.api
    @api ||= Octokit::Client.new(:oauth_token => token)
  end

  def api
    self.class.api
  end

  attr_reader :name, :branch, :left_branch, :right_branch
  def initialize(name, left_branch, right_branch)
    @name         = name
    @branch       = "#{left_branch}+#{right_branch}"
    @left_branch  = left_branch
    @right_branch = right_branch
  end

  def left_head
    @left_head ||= find_ref(left_branch)
  end

  def right_head
    @right_head ||= find_ref(right_branch)
  end

  def find_ref(ref)
    refs = api.ref(name, "heads/#{ref}")
    if refs.kind_of?(Array)
      match = refs.find { |r| r.ref == ref }
      raise Octokit::NotFound.new unless match
    else
      match = refs
    end
    match.object
  rescue Octokit::NotFound => e
    raise ArgumentError.new("#{name} doesn't have a '#{ref}' ref.")
  end

  def branch_head
    @branch_head ||= find_ref(branch)
  rescue ArgumentError
    puts "Creating #{name} - refs/heads/#{branch}@#{left_head['sha']}"
    @branch_head = api.create_ref(name, "heads/#{branch}", left_head.sha)
  end

  def verify_refs
    left_head
    right_head
    branch_head
  end

  def create_integration_branch
    verify_refs

    commit_message = "Integration branch created for #{left_branch} and #{right_branch}"
    response = api.merge(name, branch, right_head.sha, :commit_message => commit_message)

    response.respond_to?(:commit)
  rescue Octokit::NotFound => e
    puts e.message
    false
  end
end

if ARGV.size > 2
  ib = IntegrationBranch.new(ARGV[0], ARGV[1], ARGV[2])
  puts ib.left_head.inspect
  puts ib.right_head.inspect
  puts ib.create_integration_branch
else
  $stderr.puts "Incorrect usage for topic branch creation\n"
  $stderr.puts "#{$0} github/github branch1 branch2"
end