Generate release notes from closed pull requests.

Generate release notes from PRs.md

Generate release notes from PRs

By default this will look at the previous 100 commits from your local .git folder in your project. To Add release notes to an older project you might want to bump that WAY up.

Also you will need a valid GitHub token in your .env file.

GenerateReleaseNotes.new('your_org/your_project', 'path_to_location_of_prev_sha_file/previous-sha.yml', ENV['GITHUB_API_TOKEN'], true)

.env

GITHUB_API_TOKEN=YOUR_TOKEN HERE

Gemfile

source 'https://rubygems.org'

# used for automated release notes
gem 'dotenv'
gem 'git'
gem 'octokit', '~> 3.0'

generate_release_notes.rb

#!/usr/bin/env ruby

require 'bundler/setup'
require 'dotenv'
require 'git'
require 'octokit'
require 'yaml'

# load .env vars
Dotenv.load

class GenerateReleaseNotes

  def initialize(repo_name, previous_sha_file, access_token, is_test=false)
    return puts 'You must supply a valid github API token' unless access_token.length > 0
    @repo_name = repo_name
    @pull_request_notes = ['RELEASE NOTES']
    # Grab out previous sha
    @previous_sha_file = previous_sha_file
    @previous_sha_yaml = YAML::load_file(@previous_sha_file)
    @is_test = is_test
    set_versions
    # create github api client
    @client = Octokit::Client.new(access_token: access_token)
    # create git
    @git = Git.open('./')
    commits = @git.log(100)
    @newest_sha = commits.first.sha
    # start creating the notes
    scan_commits commits
    # update the notes
    update_release_notes
  end

  # grab out build verion info
  def set_versions
    @git_release_version = `git describe --tags --always --abbrev=0`.strip()
    @number_of_commits = `git rev-list master | wc -l | tr -d ' '`.strip()
  end

  # add PRs from commits
  def scan_commits(commits)
    commits.each do |commit|
      return true if @previous_sha_yaml['previous-sha'] == commit.sha
      match = commit.message.match(/pull request #(\d+) from/)
      if match
        pr_num = match.captures[0]
        pr = @client.pull_request @repo_name, pr_num
        if pr[:state] == 'closed'
          @pull_request_notes << "#### ##{pr_num} - #{pr[:title]}\n#{pr[:body]}".strip()
        end
      end
    end
  end

  def update_release_notes
    # new release notes
    release_notes = "### Build #{@git_release_version}(#{@number_of_commits}) #{Time.now.strftime("%B %-d, %Y")}\n\n"
    release_notes << <<-EOF
    #{@pull_request_notes.count > 1 ? @pull_request_notes.join("\n\n------\n\n") : 'No completed pull requests since last release.'}
    #{"\n------------\n"}
    EOF

    # add release_notes to 
    `mkdir tmp`
    File.open("tmp/#{@number_of_commits}-release-notes.md", 'w') { |f| f.write release_notes.gsub(/(#+ )/, "") }

    if @is_test
      puts release_notes.gsub(/(#+ )/, "")
    else
      # prepend new contents into release-notes
      old = File.open('release-notes.md', 'a')
      new = File.open('release-notes.new.md', 'w')
      File.open(new, 'w') { |f|
        f.puts release_notes
        f.puts File.read(old)
      }
      File.rename(new, old)

      # update the latest commit from here
      @previous_sha_yaml["previous-sha"] = @newest_sha
      File.open(@previous_sha_file, 'w') {|f| f.write @previous_sha_yaml.to_yaml }
    end
  end

end

previous-sha.yml

---
previous-sha: sha_to_start_from