Clean stale local git branches

git-clean-local

#!/usr/bin/env ruby

require 'time'
require 'optparse'

class Cleaner
  attr_accessor :whitelist, :blacklist, :cutoff_days, :confirm, :dry_run, :keep, :skip, :remove

  def initialize(options = {})
    @whitelist    = %W(master develop #{local_branch}).uniq
    @blacklist    = []
    @cutoff_days  = 30
    @confirm      = false
    @dry_run      = false
    @keep         = []
    @skip         = []
    @remove       = []
  end

  def perform
    partition_branches
    summarize
    remove_branches
  end

  def partition_branches
    local_refs.each do |last_sha, branch_name, updated_str|
      updated_at = Time.parse(updated_str)
      if whitelisted?(branch_name)
        skip << branch_name
      elsif updated_at > cutoff
        keep << branch_name
      elsif removable?(branch_name)
        remove << branch_name
      else
        skip << branch_name
      end
    end
  end

  def whitelisted?(name)
    whitelist.each do |pattern|
      case pattern
      when String
        return true if name == pattern
      when Regexp
        return true if name =~ pattern
      end
    end
    return false
  end

  def removable?(branch)
    return true if blacklist.empty?
    blacklist.each do |pattern|
      return true if branch =~ pattern
    end
    return false
  end

  def summarize
    puts "Whitelisted branches to keep:"
    skip.each { |b| puts "  #{b}" }
    puts
    puts "Recently (past #{cutoff_days} days) updated branches to keep:"
    keep.each { |b| puts "  #{b}" }
    puts
    puts "Branches to remove:"
    remove.each { |b| puts "  #{b}" }
  end

  def remove_branches
    return if dry_run
    return unless confirm || user_confirmed?
    remove.each do |branch|
      puts "Removing #{branch}"
      `git branch -D #{branch}`
    end
  end

  def user_confirmed?
    puts "Are you sure you want to remove these branches? ([Y]es/[N]o)"
    answer = gets.strip
    answer =~ /^y(es)?$/i
  end

  def local_branch
    `git name-rev --name-only HEAD`.strip
  end

  def local_refs
    `git for-each-ref refs/heads --format='%(objectname)\t%(refname:short)\t%(creatordate)'`.lines.map { |l| l.split("\t").map(&:strip) }
  end

  def cutoff
    @cutoff ||= Time.now - (60*60*24*cutoff_days)
  end

  def self.parse(args)
    opts = self.new
    parser = OptionParser.new do |o|
      o.banner = "Usage: git clean-local [options]"

      o.on("-y", "--yes", "--confirm", "Perform branch removals") do
        opts.confirm = true
      end

      o.on("--no", "--dry-run", "Show branches which will be removed, but don't remove them. Default.") do
        opts.dry_run = true
      end

      o.on("--whitelist=WHITELIST", "Comma seperated list of branch patterns to skip") do |list|
        opts.whitelist += list.split(",").map do |whitelist_item|
          /#{whitelist_item}/
        end
      end

      o.on("--blacklist=BLACKLIST", "Comma separated list of branch patterns to remove") do |list|
        opts.blacklist += list.split(",").map do |blacklist_item|
          /#{blacklist_item}/
        end
      end

      o.on("--cutoff=DAYS", "Keep branches that have been updated in past number of days") do |days|
        opts.cutoff_days = days.to_i
      end

      o.on("-h", "--help") do
        puts o
        exit
      end
    end

    parser.parse!(args)
    opts
  end
end

Cleaner.parse(ARGV).perform