Prune local branches which have merged PRs on a GitHub repo

prune_local_branches.rb

#!/usr/bin/env ruby

require 'octokit'
require 'git'
require 'optparse'
require 'io/console'

default_options = {
  :owner          => 'coupa',
  :github_repo    => 'coupa_development',
  :local_repo_dir => Dir.pwd
}

options = {}
OptionParser.new do |opts|
  opts.on("-u", "--user", "GitHub login") do |login|
    options[:login] = user
  end

  opts.on("-o", "--owner", "Github repo owner") do |owner|
    options[:owner] = owner
  end

  opts.on("-r", "--repo", "GitHub repository") do |repo|
    options[:github_repo] = repo
  end

  opts.on("-l", "--local-repo", "Local repository") do |local|
    options[:local_repo_dir] = local
  end
end.parse!

options = default_options.merge(options)

if options[:login]
  login = options[:login]
else
  puts "Github login:"
  login = gets.chomp
end

puts "Github password:"
password = STDIN.noecho(&:gets).chomp

puts "Comparing local branches against GitHub pull requests. This may take a moment..."

Octokit.configure do |c|
  c.login = login
  c.password = password
end

local_repo = Git.open(options[:local_repo_dir])

to_delete = []
local_repo.branches.local.each do |branch|
  local_sha = branch.gcommit.sha
  open_prs = Octokit.get("/repos/#{options[:owner]}/#{options[:github_repo]}/pulls",
                         {:head  => "#{options[:owner]}:#{branch.name}",
                          :state => "open"})
  closed_prs = Octokit.get("/repos/#{options[:owner]}/#{options[:github_repo]}/pulls",
                         {:head  => "#{options[:owner]}:#{branch.name}",
                          :state => "closed"})

  if open_prs.empty? && !closed_prs.empty? && closed_prs.all? { |pr| pr.merged_at && pr.head.sha == local_sha }
    to_delete << branch
  end
end

puts "The following branches have no open PRs and at least one merged PR. Do you want to delete them?"
to_delete.each { |b| puts b.name }
puts "Delete these local branches? (y/n)"
exit unless gets.chomp == "y"

to_delete.each { |b| b.delete }
puts "Branches deleted."