ruby script to summarize local branch status relative to origin

features

#!/usr/bin/env ruby

#require 'pry'
#require 'pry-byebug'

def branch(group:nil)
  case group
  when :remote
    flag = "-r"
  when :all
    flag = "-a"
  when nil, :local
    flag = ""
  end

  `git branch #{flag}`.lines.map do |line|
    fields = line.split

    if fields.first['*']
      fields[1].strip
    else
      fields.first.strip
    end
  end
end

RemoteBranches = branch(group: :remote)
LocalBranches = branch(group: :local)

base = LocalBranches.include?('develop') ? 'develop' : 'master'

merged = "git branch --no-color --merged #{base}"
nomerged = "git branch --no-color --no-merged #{base}"


prepend = ->(prefix, source) { `#{source}`.lines.map { |l| [prefix, l] } }

case ARGV[0]
when '-u'
  branches = prepend['U', nomerged]
when '-m'
  branches = prepend['M', merged]
else
  branches = prepend['U', nomerged] + prepend['M', merged]
end

branches = branches.map do |(prefix, branch)| 
  [prefix, branch.chomp.strip]
end.select do |(prefix, branch)|
  branch.sub!('* ','')
  not %w{master develop}.include?(branch)
end

width = branches.map { |(p, b)| p.length + b.length }.max

def log(branch)
  `git log -1 --pretty=format:"%Cgreen%ci %Cred%cr%Creset" #{branch}`
end

def status(branch)
  remote = "origin/#{branch}"
  if RemoteBranches.include?(remote)
    ahead = `git rev-list #{branch} ^#{remote}`.lines.count
    behind = `git rev-list ^#{branch} #{remote}`.lines.count
  else
    ahead, behind = '-', '-'
  end
  [ahead, behind]
end

lines = branches.map do |prefix, branch|
  [prefix, branch, log(branch)]
end.sort_by do |(prefix, branch, info)|
  info.split[0..1]
end.reverse.map do |prefix, branch, info|
  a, b = status(branch)
  [prefix, a, b, [branch, info].join(" " * (width - branch.length + 1))].join(" ")
end

puts lines