Git commit-msg hook that automatically adds "Refs #123" when in the branch t123, "[#123]" when in the branch s123 etc.

commit-msg

#!/usr/bin/env ruby
#
# Git commit-msg hook. If your branch name is in the form "t123", automatically
# adds "Refs #123." to commit messages unless they mention "#123" already.
# Include "#close" or "#finish" to add "Closes #123."
#
# For Pivotal Tracker, branch names like "s123" adds "[#123]".
# Include "#close" or "#finish" to add "[Finishes #123]".
#
# If you include "#noref" in the commit message, nothing will be added to
# the commit message, and the "#noref" itself will be stripped.
#
# By Henrik Nyh <http://henrik.nyh.se> 2009-09-10 under the MIT License.
#
#
# Install:
#
# cd your_project
# curl https://raw.github.com/gist/184711/93f657d58dc9c501ca4a7b56260853d8d0058117/commit-msg -o .git/hooks/commit-msg && chmod u+x .git/hooks/commit-msg
#
# Or store it centrally and symlink in your projects:
#
# curl --create-dirs https://raw.github.com/gist/184711/93f657d58dc9c501ca4a7b56260853d8d0058117/commit-msg -o ~/.githooks/commit-msg && chmod u+x ~/.githooks/commit-msg
# cd your_project
# ln -s ~/.githooks/commit-msg .git/hooks

PREFIXES = {
  # RedMine, Trac etc.
  "t" => { :reference => "Refs #%s.", :finish => "Closes #%s." },
  # Pivotal Tracker.
  "s" => { :reference => "[#%s]",     :finish => "[Finishes #%s]" },
}

FLAGS = [
  NOREF  = "noref",
  CLOSE  = "close",
  FINISH = "finish"
]
CLOSING_FLAGS = [ CLOSE, FINISH ]


branchname = `git branch --no-color 2> /dev/null`[/^\* (.+)/, 1].to_s


if m = branchname.match(/\A(#{Regexp.union(*PREFIXES.keys)})-?(\d+)/)
  prefix, ticket_number = m.captures
  finish    = PREFIXES[prefix][:finish] % ticket_number
  reference = PREFIXES[prefix][:reference] % ticket_number
else
  exit
end

message_file = ARGV[0]
message = File.read(message_file).strip
exit if message.include?("##{ticket_number}")


# Determine if any of the flags are included. Make a note of which and then remove it.
message.sub!(/(?:^|\s)#(#{Regexp.union(*FLAGS)})\b/, '')
flag = $1

message =
  case flag
  when NOREF
    message
  when *CLOSING_FLAGS
    [ message, finish ].join(" ")
  else
    [ message, reference ].join(" ")
  end

File.open(message_file, 'w') {|f| f.write message }