Git hook for NodeJS development

post-checkout

#!/bin/sh

## Checks to see if the package.json changed following a checkout or merge and then automatically
## runs `npm install`. If you use yarn or pnpm, then change the line with `npm install` as needed.
##
## add this code to both .git/hooks/post-checkout and .git/hooks/post-merge 

file="package.json"
if [[ $(git diff HEAD@{1}..HEAD@{0} -- "${file}" | wc -l) -gt 0 ]]
then
  echo "Package.json changed, running npm install"
  npm install
else
  echo "No change in package.json"
fi