This script lets you easily see what commits were made after the last release of your project. Usefull to track changes between releases.

git_commits_since_release.rb

new_tag_version = ARGV[0]

GIT_REPOS = []

class GitRepository
  GIT_MERGE_COMMITS = /(Merge pull request)|(Merge branch)/
  GIT_HASH_LENGTH = 8

  attr_reader :name

  def initialize(name)
    @name = name
  end

  def important_commits_after_last_tag
    all_commits = `cd #{name} && git log \`git describe --tags --abbrev=0\`..HEAD --oneline`.split("\n")
    useful_commits = remove_git_commits(all_commits)
    remove_git_hash!(useful_commits)
  end

  def new_tag_message
    commit_messages = important_commits_after_last_tag
    output = "## Summary\n\n"
    commit_messages.each do |msg|
      output += "* #{msg}\n"
    end
    output
  end

  private

  def remove_git_commits(commits)
    commits.select { |commit| commit !~ GIT_MERGE_COMMITS }
  end

  def remove_git_hash!(commits)
    commits.map! { |commit| commit[GIT_HASH_LENGTH..-1] }
  end
end

repositories = GIT_REPOS.map { |repo| GitRepository.new(repo) }
commits = repositories.map(&:new_tag_message)

puts commits