gistfile1.txt

git new release # creates a new release branch (release/X.Y.Z) from the latest tagged version incrementing minor version from upstream's integration branch
git new release --bump major # creates a new release branch (release/X.Y.Z) from the latest tagged version incrementing major version
git new feature branch-name # creates a new feature branch (feature/branch-name) from upstream's integration branch
git new hotfix branch-name # creates a new hotfix branch (hotfix/branch-name) from upstream's stable branch

git-new.rb

#! /usr/bin/env ruby

require "thor"
require 'rugged'
require 'versionomy'

class GitNew < Thor
  desc "release", "New release branch"

  method_option :bump, default: "minor"

  def release
  	fetch_upstream
    new_branch("release/#{next_version(options[:bump])}", param(:integration))
  end

  desc "hotfix", "New hotfix branch"

  def hotfix(name)
    fetch_upstream
    new_branch("hotfix/#{name}", param(:stable))
  end

  desc "feature", "New feature branch"

  def feature(name)
    fetch_upstream
    new_branch("feature/#{name}", param(:integration))
  end

  desc "set", "Set config options"
  long_desc <<-LONGDESC
    `stable`: Stable branch name (master)\x5
    `integration`: Integration branch name (devel)\x5
    `upstream`: Upstream remote (origin)
  LONGDESC

  def set(key, value)
    repo.config["gitnew.#{key}"] = value
  end

  def self.exit_on_failure?
    true
  end

  protected

  def next_version(bump)
    last_version.bump(bump)
  end

  def last_version
    @last_version ||= Versionomy.parse(IO.popen(["git", "describe", "--tags", "--abbrev=0", "#{param(:upstream)}/#{param(:stable)}"]).read.strip)
  end

  def new_branch(name, from)
    system "git", "checkout", "-b", name, "#{param(:upstream)}/#{from}"
  end

  def fetch_upstream
    system "git", "fetch", param(:upstream)
  end

  def upstream
    @upstream ||= Rugged::Remote.lookup(repo, param(:upstream))
  end

  def param(key)
    repo.config["gitnew.#{key}"] or raise "#{key} is not configured"
  end

  def repo
    @repo ||= Rugged::Repository.new(Dir.pwd)
  end
end

GitNew.start