Git pre commit hook to add the jira ticket id to the commit message

prepare-commit-msg

#!/bin/sh
#
# A hook script to prepare the commit log message.
# If the branch name it's a jira Ticket.
# It adds the branch name to the commit message, if it is not already part of it.
# https://stackoverflow.com/questions/5894946/how-to-add-gits-branch-name-to-the-commit-message/59831864#59831864

branchPath=$(git symbolic-ref -q HEAD) #Somthing like refs/heads/myBranchName
branchName=${branchPath##*/}      #Get text behind the last / of the branch path

regex="(PROJECTNAME-[0-9]*)"
# Enable case insensitive match, jira project codes are uppercase
shopt -s nocasematch

if [[ $branchName =~ $regex ]]
then
    # Get the captured portion of the branch name, and change it to upper case.
    # Mac bash version is 3, so can't use the `^^` to uppercase the string, using `tr` command instead.
    # If you do not need the uppercase, use the BASH_REMATCH dirrectly
    # jiraTicketName${BASH_REMATCH[1]}
    jiraTicketName=$(echo ${BASH_REMATCH[1]} | tr [:lower:] [:upper:])

    originalMessage=`cat $1`

    # If the message already begins with PROJECTNAME-#, do not edit the commit message.
    if [[ $originalMessage == $jiraTicketName* ]]
        then
        exit
    fi

    sed -i '.bak' "1s/^/$jiraTicketName: /" $1 #Insert branch name at the start of the commit message file
fi
# else => do not edit the commit message.