This is my git pre commit hook that would work for linux and windows systems

puppet pre-commit

#!/bin/bash

against=$1
FILES=`git diff --cached --name-only --diff-filter=ACM`
# validate json files
for file in $FILES
do

   # validate json files
   if [[ $file == *.json ]]; then
       echo "Validating json file: $file"
       python -m json.tool $file > /dev/null

   # validate puppet manifests
   elif [[ $file == *.pp ]]; then
       echo "Validating puppet file: $file"
       puppet parser validate $file

   fi
   # if any validation failed display error
   if [[ $? != 0 ]]; then
     exit 1
   fi

done

exit 0