自動でコミットメッセージに絵文字を付け加える ref: http://qiita.com/eccyan/items/7514c2c2eb14aab8f63a

prepare-commit-msg

#!/usr/bin/env ruby

# :up: :up: when improving the format/structure of the code
# :hammer: :hammer: when refactoring the code
# :chart_with_upwards_trend: :chart_with_upwards_trend: when improving performance
# :memo: :memo: when writing docs
# :bug: :bug: when fixing a bug
# :fire: :fire: when removing code or files
# :green_heart: :green_heart: when fixing the CI build
# :white_check_mark: :white_check_mark: when adding tests
# :lock: :lock: when dealing with security
# :arrow_double_up: :arrow_double_up: when upgrading dependencies
# :arrow_double_down: :arrow_double_down: when downgrading dependencies
# :hatching_chick: :hatching_chick: when adding new features

EMOJIS = {
  # up: [/Improve(?:s)? /i, /Update(?:s)? /i, /Replace(?:s)? /i, /Change(?:s)? /i, /Tweak(?:s)? /i],
  hammer: [/Refactor(?:s)? /i, /Rename(?:s)? /i],
  chart_with_upwards_trend: [/Tuneup(?:s)? /i],
  memo: [/Write(?:s)? /i],
  bug: [/Fix(?:es)? (?:(?!spec|linter|test))/i],
  fire: [/Remove(?:s)? /i],
  green_heart: [/Fix(?:es)? broken (?:spec|linter|test)(?:s)?/i],
  white_check_mark: [/Add(?:s)? (?:spec|test)(?:s)? /i],
  lock: [/Secure(?:s)? /i],
  arrow_double_up: [/Upgrade(?:s)? /i],
  arrow_double_down: [/Downgrade(?:s)? /i],
  hatching_chick: [/Add(?:s)? (?:(?!spec|test))/i, /Create(?:s)? /i, /Introduce(?:s)? /i],
}

EXCLUDES = [
  /Merge/i,
]

commit_msgs = File.readlines(ARGV[0])
commit_msgs[0] = commit_msgs.first.gsub(/:.+: /i, '')

unless Regexp.union(EXCLUDES).match(commit_msgs.first)
  emoji = EMOJIS.map do |key, regex|
    if Regexp.union(regex).match(commit_msgs.first)
      ":#{key}:"
    end
  end.compact.uniq.first || ':up:'

  open(ARGV[0], 'w') do |file|
    file.print "#{emoji} "
    file.puts commit_msgs
  end
end