huginn_changelog.rb

# OCTOKIT_ACCESS_TOKEN=yourtoken ruby huginn_changelog.rb

require 'json'
require 'octokit'
require 'rugged'

AFTER_NUMBER = 2607

pull_requests = unless File.exists?('pull_requests.dump')
  Octokit.auto_paginate = true
  pull_requests = Octokit.pull_requests('huginn/huginn', :state => 'closed', direction: 'asc')
  File.open('pull_requests.dump', 'w').write(Marshal.dump(pull_requests))
  pull_requests
else
  Marshal.load(File.read('pull_requests.dump'))
end

commits_from_pr = []
changes = []

class Change
  attr_reader :date, :commit, :pr, :title

  def initialize(date: nil, commit: nil, pr: nil, title: '')
    @date = date
    @commit = commit
    @pr = pr
    @title = title
  end

  def to_s
    "| #{date.strftime('%b %d, %Y')}   | #{title} #{link} |"
  end

  def link
    if pr
      "[#{pr}](https://github.com/huginn/huginn/pull/#{pr})"
    else
      "[#{commit[0..8]}](https://github.com/huginn/huginn/commit/#{commit})"
    end
  end

  def <=>(other)
    date <=> other.date
  end
end

first_commit_date = nil
current_changelog = File.read('CHANGES.md')

pull_requests.each do |pr|
  first_commit_date = pr[:merged_at] if pr[:number] == AFTER_NUMBER
  next if pr[:number] <= AFTER_NUMBER
  next if pr[:merged_at] == nil
  next if current_changelog.include? "[#{pr[:number]}]"

  changes << Change.new(date: pr[:merged_at], pr: pr[:number], title: pr[:title])

  if !File.exists?('commits_from_pr.dump')
    commits_from_pr += Octokit.pull_request_commits('huginn/huginn', pr[:number]).map { |c| c[:sha] }
  end
end

if File.exists?('commits_from_pr.dump')
  commits_from_pr = Marshal.load(File.read('commits_from_pr.dump'))
else
  File.open('commits_from_pr.dump', 'w').write(Marshal.dump(commits_from_pr))
end

repo = Rugged::Repository.new(".")
walker = Rugged::Walker.new(repo)
walker = Rugged::Walker.new(repo).each do |commit|
  next if commit.committed_date < first_commit_date
  next if commits_from_pr.include? commit.id
  next if commit.message.include? 'Merge pull request'
  changes << Change.new(commit: commit.id, date: commit.committed_date, title: commit.message.split("\n").first.strip)
end

puts changes.sort.reverse.map(&:to_s).join("\n")