Git log と GitHub Issues から Changelog を作成する。

changelog.rb

require 'open3'
require 'pp'
require 'json'
require 'date'
require 'rubygems'
require 'faraday'
require 'ostruct'
require 'erb'
require 'time'

repo = ARGV[0]

out, err, status = Open3.capture3('git tag')
version_tags = out.split(/\n/).select{|v| v =~ /^v[\d.]+$/}.sort

out, err, status = Open3.capture3('git log #{version_tags.first}...HEAD --oneline')
is = out.split(/\n/)
is.map! do |line|
  hash, *message = line.split(/\s+/)
  message = message.join(' ')
  matches, issue_no = message.match(/^.*#(\d+).*$/).to_a
  next if issue_no.nil?
  issue_no.to_i
end
is = is.compact.uniq

connection = Faraday::Connection.new(url: 'https://api.github.com')
response = connection.get "/repos/mrk21/#{repo}/issues?state=closed"
issues = JSON.parse(response.body)
issues = issues.find_all{|v| is.include?(v['number'].to_i)}

change_log = issues.reduce({}) do |m,v|
  labels = v['labels'].map{|v| v['name']}
  type = labels.include?('enhancement') ? 'Future' : labels.include?('bug') ? 'Bugfix' : nil
  next m if type.nil?
  next m if v['milestone'].nil?
  milestone = v['milestone']['title'].match(/^[\d.]+$/).to_a.first
  next m if milestone.nil?
  milestone = (milestone.split('.') + [0])[0..2].join('.')
  m[milestone] ||= OpenStruct.new(
    info: OpenStruct.new(
      milestone: milestone,
      due_on: Time.parse(v['milestone']['due_on'], Time.now.utc).getlocal.strftime('%Y-%m-%d'),
    ),
    commits: []
  )
  m[milestone].commits.push OpenStruct.new(
    id: v['number'].to_i,
    url: v['html_url'].strip,
    title: v['title'].strip.gsub(/\.$/,''),
    type: type,
  )
  m
end

puts ERB.new(<<-MD,nil,'-').result(binding)
# Changelog
<% change_log.each do |k,v| %>
## [<%= k %>](https://github.com/mrk21/#{repo}/tree/v<%= k %>) - <%= v.info.due_on %>

<% v.commits.each do |v| -%>
* <%= v.type %> [#<%= v.id %>](<%= v.url %>): <%= v.title %>
<% end -%>
<% end -%>
MD