git hook to run a command after `git pull` if a specified file was changed.In this example it's used to run `npm install` if package.json changed and `bower install` if `bower.json` changed.Run `chmod +x post-merge` to make it executable then put it into `.git/hooks/`.

post-merge

#!/usr/bin/env bash
# MIT © Sindre Sorhus - sindresorhus.com
# https://gist.github.com/sindresorhus/7996717

# git hook to run a command after `git pull` if a specified file was changed
# Run `chmod +x post-merge` to make it executable then put it into `.git/hooks/`.

changed_files="$(git diff-tree -r --name-only --no-commit-id ORIG_HEAD HEAD)"

check_run() {
	echo "$changed_files" | grep --quiet "$1" && eval "$2"
}

# Install script
# http://stackoverflow.com/questions/3462955/putting-git-hooks-into-repository/3464399#3464399

# In this example it's used to run `npm install` if package.json changed and `bower install` if `bower.json` changed.

# Updating npm packages
check_run package.json "npm install"

# Updating bower packages
# check_run bower.json "bower install"

# Updating git submodules
# check_run .gitmodules "git submodule init && git submodule update"

# Installing composer dependencies
# check_run composer.json "composer install"

# For those who use gulp
# check_run web/assets "gulp --production"