prepare-commit-msg

#!/bin/sh
#
# Automatically adds issue number (optional) and ticket number based on branch name or
# description to every commit message.
#
# Copy this file to .git/hooks under your local repository directory
# PS: If you're on linux you may need to change "sed -En" to "sed -rn"
#
#   Example:
#
#   Branch name:
#   765-APP-10-my-branch-name
#
#   Will generate the following template for all commit messages of this branch:
#
#   JIRA APP-10
#   Issue #765
#
#
# You may alternatively use the usual branch name (e.g. 765-my-branch-name)
# and perform:
#   > git branch --edit-description
#   > APP-10
#
branch_name="$(git symbolic-ref HEAD 2>/dev/null)" ||
branch_name="(unnamed branch)"     # detached HEAD
branch_name=${branch_name##refs/heads/}
issue=$(echo $branch_name | sed -En "s/^([0-9]+)-.*/\1/p")
ticket=$(git config branch."$branch_name".description) ||
ticket=$(echo $branch_name | sed -En "s/^([0-9]+-)?([^-]+-[0-9]+).*/\2/p")
[ -z "$ticket" ] && ticket="(TICKET_NUMBER)"

firstLine=$(head -n1 $1)

# Check that this is not an amend by checking that the first line is empty
if [ -z "$firstLine"  ] && [ -n "$ticket" ]; then
  if [ -n "$issue" ]; then
    sed -i '' '1s/^/\
\
JIRA '$ticket'\
Issue #'$issue'/' $1 # Insert issue and ticket
  else
    sed -i '' '1s/^/\
\
JIRA '$ticket'/' $1 # Only insert ticket
  fi
fi