install babel and transpile a directory of files appropriate for your specified environment (e.g., node 6, ie9+ browsers)

instababel.sh

function instababel(){
  outputEnv=$1
  destDir=$2
  srcDir=$3
  if [[ ! $3 ]]; then
    echo "Must call as $ instababel <outputEnv> <srcDir> <destDir>"
    echo "outputEnv options are node6 & ie9+"
    return;
  fi
  
  if [[ $outputEnv = 'node6' ]]; then
    rm -rf $destDir
    npm i babel-cli babel-preset-stage-2 babel-preset-node6 babel-plugin-transform-runtime
    ./node_modules/.bin/babel $srcDir --out-dir $destDir --presets babel-preset-node6,stage-2 --plugins transform-runtime --compact false --no-babelrc
    return
  fi
  # if [[ $outputEnv = 'ie9+' ]]; then
  #   return
  #   don't need this right now.  Can make it later.
  # fi
  echo No babel config for $outputEnv yet.  Make one!
}
export -f instababel;