cleanup merged branches

repo_cleanup.rb

#! /usr/bin/env ruby

# if run inside a git repo, this will pull current master and force remove all branches that have no diff against master.
# this is useful if you use squash-merge- or rebase-based merge strategies, and does not require anything particular of the 
# developer to use.  
in_repo = system("git status")

unless in_repo
  puts "run this from inside a git repo"
  exit 1
end

git_status = `git status 2>&1`

if git_status.match(/Changes to be committed:/) || git_status.match(/Changes not staged for commit:/)
  puts "stash or commit state first!"
  exit 1
end

`git checkout master`
`git pull origin master`
branches = `git branch`.split.reject {|bn| ["master", "*"].member? bn }

branches.each do |bn|
  `git checkout #{bn}`
  merged = system("git merge origin/master -m 'merged by repo_cleaner'")
  diff = nil
  if merged
    diff = `git diff origin/master`
  else
    reset = system("git reset --hard")
    exit(1) unless reset
  end
  `git checkout master`
  if diff == ""
    `git branch -D #{bn}`
  end
end