Bash script to be used as post-merge git hook to install NPM modules recursively only for changed package.json files (and package-lock.json files for npm > v5)

install_updated_packages.sh

#!/bin/bash

PURPLE='\033[0;35m'
CYAN='\033[0;36m'
NC='\033[0m' # No Color

PROJECT_DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd) # script assumes that you placed it in the root of your project dir

changed_files="$(git diff-tree -r --name-only --no-commit-id ORIG_HEAD HEAD)" # find all files changed by commit first 

printf "${PURPLE}\nChecking updated NPM modules.. ${NC} \n" 

PROCESSED_DIRS=()

for package in $(echo "$changed_files" | grep "package.json") # iterate over changed package.json files
do 
  printf "\n${CYAN}Installing updated NPM modules for $package${NC}\n\n"
  package_path="$PROJECT_DIR/$package"
  package_dir=$(dirname "${package_path}")
  printf "npm install --prefix $package_dir\n\n"
  
  npm install --prefix $package_dir # install modules for changed package.json file
  PROCESSED_DIRS+=($package_dir)
done

for package in $(echo "$changed_files" | grep "package-lock.json")
do 
  package_path="$PROJECT_DIR/$package"
  package_dir=$(dirname "${package_path}")
  
  if [[ " ${PROCESSED_DIRS[@]} " =~ " ${package_dir} " ]]; then
    printf "\Contains $package_dir"
  else
    printf "\nDoes not contain $package_dir"
    printf "\n${CYAN}Installing updated NPM modules for $package${NC}\n\n"
    printf "npm install --prefix $package_dir\n\n"

    npm install --prefix $package_dir
  fi
done

echo "All NPM modules are up-to-date"