Never commit ruby syntax errors

pre-commit

#!/usr/bin/env bash
set -e

files() {
    git diff --name-only --cached --full-index
}

check() {
    while read file; do
        filename=$(basename "$file")
        extension="${filename##*.}"
        if [ "rb" = $extension ]; then
            if [ -f "$file" ]; then ruby -c $file >/dev/null; fi
        fi
    done
}

echo "Checking ruby syntax..."
files | check