npm-install-if-necessary

#!/bin/bash
set -euo pipefail

which npm

# npm install should also be run if package.json has been modified since last npm install run --> copy package.json to ./node_modules/package.json and compare!!!
if ! ls ./node_modules/package.json &> /dev/null || ! diff ./package.json ./node_modules/package.json &> /dev/null ; then
    echo "npm install not run or outdated, running..." 1>&2
    npm install 1>&2
    cp ./package.json ./node_modules/package.json 1>&2
fi