git post checkout hook for changes detection

post-checkout-changes-check.sh

#!/bin/bash

# https://gist.github.com/gurglet/1780139

# Git post checkout hook.
# Reminds you of South migration changes when switching branches.
# Can be useful when you are testing out a branch from
# someone else that requires migrations.
# Put the file in .git/hooks/post-checkout

PREVIOUS_HEAD=$1
NEW_HEAD=$2
BRANCH_SWITCH=$3

if [ $PREVIOUS_HEAD != $NEW_HEAD ]; then
    # Start from the repository root.
    cd ./$(git rev-parse --show-cdup)

    # Check if any migrations have changed.
    CHANGED=`git diff $PREVIOUS_HEAD $NEW_HEAD --name-status | grep "^M.*composer.lock"`
    if [ $? -eq "0" ]; then
        echo -e "\033[7;31m Beware. composer.lock is changed. Update by running:"
        echo -e "\033[7;31m  composer install"
    fi

    # Check if submodules have been changed
    MODULES=`git diff $PREVIOUS_HEAD $NEW_HEAD --name-status | grep "\.gitmodules$"`
    if [ $? -eq "0" ]; then
        echo -e "\033[7;31m The submodules in this project has changed. Update submodules by running:"
        echo -e "\033[7;31m  git submodule update --init"
    fi
fi