Run maven on a clean directory, reflecting ONLY what will be in the commit, and excluding any other files in the working directory that might affect the build

pre-commit-mvn.sh

#!/bin/bash
echo "running pre-commit hooks"

STAGED_FILES_CMD=`git diff --cached --name-only | grep -E "(\.java$)|(pom.xml)"`
# Determine if a file list is passed
echo "INPUT: $#"
if [ "$#" -eq 1 ] ; then
 oIFS=$IFS
 IFS='
 '
 SFILES="$1"
 IFS=$oIFS
fi
SFILES=${SFILES:-$STAGED_FILES_CMD}

echo "STAGED_FILES_CMD: $STAGED_FILES_CMD, SFILES: $SFILES"
# Determine whether need run maven java test
if [ "$SFILES" == "" ] ; then
 echo "no need to run maven test";
 exit 0;
fi

echo "Running 'maven test' for errors"

# retrieving current working directory, if don't want to call this hook, run git commit --no-verify
CWD=`pwd`
MAIN_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
# go to main project dir
cd $MAIN_DIR/../../

mkdir -p ${MAIN_DIR}/logs/

# Check out a copy of the index
tmpdir=$(mktemp -d)                # or your other chosen method
trap "rm -rf $tmpdir" 0 1 2 3 15   # do something different in other languages

GIT_WORK_TREE=$tmpdir git checkout-index --all

cd  $tmpdir

set -o pipefail
mvn test package | tee ${MAIN_DIR}/logs/mvn.log

RESULT=$?

# clean up
rm -rf $tmpdir

# go back to current working dir
cd $CWD

if [ $RESULT -ne 0 ] ; then
  echo "Error while testing the code, commit aborted"
  exit 1
fi