add issue number from branch to commit msg

prepare-commit-msg

#!/bin/bash

# Extact issue tag (e.g. feature/TAG-123 -> TAG-123, ANOTHERTAG-123-description -> ANOTHERTAG-123)
fetch_issue_tag() {
  git rev-parse --abbrev-ref HEAD | grep -e '[A-Z]\+-[0-9]\+' -o
}

BRANCH_NAME=$( git branch | grep '*' | sed 's/* //' )
ISSUE_TAG=$( fetch_issue_tag )
FIRSTLINE="$( head -n 1 "$1" )"
BODY="$( tail -n +2  "$1" )"

# Skip editing the commit message when rebasing.
if [[ "$BRANCH_NAME" != '(no branch'* ]]
then
    # Append the issue tag if the issue tag is in the branch
    # and not already in the commit message.
    if [[ -z "${FIRSTLINE//}" ]]
    then
        if [[ -n "$ISSUE_TAG" ]]
        then
            NEW_MESSAGE="$ISSUE_TAG: \n$BODY"
            printf "$NEW_MESSAGE" > "$1"
        else
            NEW_MESSAGE="# Issue tag? \n$BODY"
            printf "$NEW_MESSAGE" > "$1"
        fi
    fi
fi

chmod +x .git/hooks/prepare-commit-msg