Pre-commit hook to prefix the jira issue number to commit message using ruby

prepare-commit-msg

#!/usr/bin/env ruby

class PrepareCommitMsgHandler
  JIRA_PROJECT_ABBREVIATIONS = ["JIRA_BOARD_ABBRV"].freeze # Replace JIRA_BOARD_ABBRV with you Jira board abbreviation

  def handle
    filepath = ARGV[0]
    commit_file = File.open(filepath, "r")
    commit_message = commit_file.read
    update_commit_message(commit_message, filepath) if is_issue_branch? && !is_commit_prefixed?(commit_message)
    exit 0
  end

  private

    def red_background(text)
      "\e[41m#{text}\e[0m"
    end

    def is_issue_branch?
      JIRA_PROJECT_ABBREVIATIONS.include?(current_branch.split("-").first.downcase)
    end

    def is_commit_prefixed?(message)
      JIRA_PROJECT_ABBREVIATIONS.include?(message.split(" ").first.split("-").first.downcase)
    end

    def current_branch
      result = %x{git branch}.split("\n")
      if result.empty?
        puts red_background("It seems your app is not a git repository.")
        exit 1
      else
        result.select { |b| b =~ /^\*/ }.first.split(" ").last.strip
      end
    end

    def issue_number
      current_branch.split("-").first(2).join("-")
    end

    def update_commit_message(message, filepath)
      commit_message = issue_number + " " + message
      File.write(filepath, commit_message)
    end
end

PrepareCommitMsgHandler.new.handle