Use this script as git pre-commit hook to automatically minify JS and CSS files in a Grails project (specifically GSCF in this case, https://github.com/thehyve/GSCF). Installation instructions: put this text in .git/hooks/pre-commit, and make it executable (shmod +x pre-commit). Also, install yuicompressor, e.g. via 'brew install yuicompressor' …

gistfile1.sh

#!/bin/bash

# Search YUI Compressor anywhere in your home dir
echo "Searching for YUI Compressor..."
YUIC=`which yuicompressor`
if ! [ $YUIC ]
then
    echo "Unable to find YUI Compressor! Goodbye!"
    exit
fi

echo -e "YUI Compressor found! Start compressing...\n"

function _c
{
    fname=$(basename "$1")
    dest=$(dirname "$1")
    ext="${fname##*.}"
    dest_fname="$dest/${fname%.*}.min.$ext"
    echo "Compressing $1..."
    $YUIC $1 > $dest_fname
    git add $dest_fname
    echo "Done."
    echo ""
}

for file in $(ls web-app/js/*.js web-app/css/*.css|grep -vi min.);
do
    _c $file
done

echo "That is all."