list and clear branches match a prefix

clear_branches.rb

#! /usr/bin/ruby

class BranchList < Struct.new(:name_prefix)
  require 'set'

  COMMANDS = {
    :remote => {
      :list   => 'git remote show origin',
      :remove => 'git push origin :%s'
    },
    :local  => {
      :list   => 'git branch',
      :remove => 'git branch -D %s'
    }
  }

  def initialize(*args)
    @branches = Hash.new { |h, k| h[k] = Set.new }
    @removed  = Hash.new { |h, k| h[k] = Set.new }

    super
  end

  def print(scope)
    get_branches(scope)

    if @branches[scope].any?
      puts "Listing all #{scope} branches"
      @branches[scope].each { |br| puts "\t#{br}" }
    else
      puts "There are no #{scope} branches that match that prefix"
    end

    puts
  end

  def remove(scope)
    get_branches(scope)

    puts "Removing all #{scope} branches"

    @branches[scope].each do |branch|
      next if @removed[scope].include?(branch)

      system( COMMANDS[scope][:remove] % branch )
    end
  end

  private

  def get_branches(scope)
    return unless @branches[scope].empty?

    grep_output = `#{COMMANDS[scope][:list]} | grep #{name_prefix}`

    grep_output.each_line do |line|
      @branches[scope].add( line.match(/(#{name_prefix}[^\s]*)/)[0] )
    end
  end

end

if __FILE__ == $0
  if branch_prefix = ARGV.first

    list = BranchList.new(branch_prefix)

    list.print(:remote)
    list.print(:local)

  else
    $stderr.puts 'You must specify the prefix of a branch name.'
  end
end