A prepare-commit-msg git hook to prepend JIRA tickets to commit messages.

prepare-commit-msg

#!/bin/bash

# Put this into .git/hooks/prepare-commit-msg and mark it as executable
# This hook will prepend JIRA ticket numbers to your commit messages. It works with -m and with the plain `git commit`.

# This expects your branches to be in one of these formats:
# 1. `(feature|bug|fix)/JIRA-XXX-some-description`
# 2. `(feature|bug|fix)/JIRA-XXX`
# 3. `JIRA-XXX-some-description`
# 4. `JIRA-XXX`


# constant regex
TICKET_TYPES="(feature|bug|fix|bugfix)"
JIRA_TICKET="[A-Z]{2,5}-[0-9]+"
DESCRIPTION=".*"
BRANCH_REGEX="^($TICKET_TYPES/)?($JIRA_TICKET)(-$DESCRIPTION)?$"

# rvar is the return value of functions...
rvar=

parse() {
  branch=$1

  if [[ $branch =~ $BRANCH_REGEX ]]
  then
    ticket="${BASH_REMATCH[3]}"
    rvar=$ticket
  fi
}


# inputs
COMMIT_MSG_FILE=$1
COMMIT_MODE=$2
SHA1=$3

COMMIT_MSG=$(cat "$COMMIT_MSG_FILE")

GIT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
parse $GIT_BRANCH
ticket=$rvar

if [[ -z "$GIT_BRANCH" ]]
then
  echo "prepare-commit-msg: no git branch; no action"
  exit 0
fi

if [[ -z "$ticket" ]]
then
  echo "prepare-commit-msg: cannot parse ticket; no action"
  exit 0
fi

cleaned_msg=$(echo "$COMMIT_MSG" | sed -e '/^#/d')
if [[ $cleaned_msg =~ $ticket ]]
then
  echo $cleaned_msg
  echo "prepare-commit-msg: found ticket in message; no action"
  exit 0
fi

if [[ "$COMMIT_MODE" = "message" ]]
then
  echo "prepare-commit-msg: 'message' commit type; prepend ticket"
  echo "${ticket}: $COMMIT_MSG" > "$COMMIT_MSG_FILE"
elif [[ -z "$COMMIT_MODE" ]]
then
  echo "prepare-commit-msg: no commit type; prepend ticket"
  echo "${ticket}: " > "$COMMIT_MSG_FILE"
  echo "$COMMIT_MSG" >> "$COMMIT_MSG_FILE"
fi