Git hook to change mvn version

post-checkout

#!/bin/bash

# This way you can customize which branches should be skipped when
# prepending commit message. 
if [ -z "$BRANCHES_TO_SKIP" ]; then
  BRANCHES_TO_SKIP=(master develop test)
fi

if [ -z "$MAIN_BRANCH" ]; then
    MAIN_BRANCH="develop"
fi

PREV_HEAD="$1"
NEW_HEAD="$2"
BRANCH_SWITCH="$3"

if [ -z "$BRANCH_SWITCH" ] || [ $BRANCH_SWITCH -eq 0 ]; then
    exit 0 # this was a file checkout
fi

ZERO="0000000000000000000000000000000000000000"
if [ "$PREV_HEAD" = "$ZERO" ]; then
    exit 0 # this was a clone
fi

BRANCH_NAME=`git rev-parse --abbrev-ref HEAD`
git show-ref --verify --quiet refs/heads/$BRANCH_NAME
if [ $? -ne 0 ]; then
    # not a branch
    exit 0
fi

BRANCH_NAME=$(git symbolic-ref --short HEAD)
BRANCH_NAME="${BRANCH_NAME##*/}"
BRANCH_EXCLUDED=$(printf "%s\n" "${BRANCHES_TO_SKIP[@]}" | grep -c "^$BRANCH_NAME$")

# Switching version based on the branch name
if ! [ $BRANCH_EXCLUDED -eq 1 ]; then
    cd `git root`
    
    # get current version of the top level pom
    CURRENT_VERSION=$(git cat-file blob $MAIN_BRANCH:pom.xml | mvn --non-recursive help:evaluate -Dexpression=project.version --file /dev/stdin | grep -v '\[.*')

    # extract version suffix
    PREFIX=$(echo $CURRENT_VERSION | cut -d \- -f 1)

    # build new version
    NEW_VERSION=$PREFIX-$BRANCH_NAME-SNAPSHOT

    BRANCH_VERSION=$(git cat-file blob HEAD:pom.xml | /neo/apps/apache-maven/bin/mvn --non-recursive help:evaluate -Dexpression=project.version --file /dev/stdin | grep -v '\[.*')
   
    # run maven versions plugin to set new version
    if ! [ "$BRANCH_VERSION" = "$NEW_VERSION" ]; then
        echo "Changing artifact version from '[$CURRENT_VERSION]' to [$NEW_VERSION]"
        
        mvn versions:set -DgenerateBackupPoms=false -DnewVersion=$NEW_VERSION

        echo "New artifact version [$NEW_VERSION] for branch [$BRANCH_NAME]"
        COMMIT_MSG="Changed artifact version from '[$CURRENT_VERSION]' to [$NEW_VERSION]"
        git commit -am"$COMMIT_MSG"
    fi
    cd -
fi