Find git commit when a package was introduced in the package.json file in a git repo.

package_json_find_when_introduced.sh

prev_cmt=""
for cmt in $(git lg  package.json | awk '{print $2}'); 
do 
  git co $cmt >/dev/null 2>&1
  cat package.json | grep 'package-name' >/dev/null 2>&1
  # will fail if does not find the package-name in the current commit
  if [ $? -ne 0 ] ; then
    echo "cmt: $cmt"           
    echo "prev_cmt: $prev_cmt" 
    git co main
    break;
  fi
  
  # store the last seen commit
  prev_cmt=$cmt
done