git-prune-and-delete

#!/usr/bin/env ruby

require "io/console"

LINE_START = " * [pruned] origin/"

def error(message, error_code=-1)
  STDERR.puts message
  exit(error_code)
end

def yesno
  case $stdin.getch
    when "Y" then true
    when "y" then true
    when "N" then false
    when "n" then false
    else true
  end
end

def pruned_branches
  $pruned_branches ||= begin
    branches = `git remote prune origin`
    error(branches, $?.exitstatus) unless $?.success?

    exit if branches.empty?

    puts branches

    branches.lines.select { |line| line.start_with?(LINE_START) }.map { |line| line.gsub(LINE_START, '').strip }
  end
end

def local_branches
  $local_branches ||= begin
    branches = `git branch`
    error(branches, $?.exitstatus) unless $?.success?
    branches.lines.map { |line| line[2..-1].strip }
  end
end

def deletable_branches
  local_branches & pruned_branches
end

def perform_deletion
  puts "\nDelete:"

  deletable_branches.each do |branch|
    print "  #{branch}? (Y/n): "
    if yesno
      puts "deleting"
      `git branch -D #{branch}`
    else
      puts "skip"
    end
  end
end

perform_deletion if deletable_branches.any?