Node.js direnv setup

.envrc

# Either use node version specified in package.json
use node package.json

# Or a specific version
use node 5.0.0

# Rest of direnv setup..
export FOO=BAR

direnvrc

use_node() {
  layout node

  local node_version=$1

  if [ "$node_version" == "package.json" ]; then
    # Requires jq: `brew install jq`
    node_version=`jq --raw-output .engines.node package.json | tr -d "<=> "`
  fi

  local node_path=${NODE_DIR:-/usr/local/n/versions/node}

  if [ -x "$node_path/$node_version/bin/node" ]; then
    PATH_add $node_path/$node_version/bin
  elif [ -x "$node_path/v$node_version/bin/node" ]; then
    # Support nvm users (nvm prefixes versions with 'v')
    PATH_add $node_path/v$node_version/bin
  else
    echo "!!! Node.js version $node_version is not installed"
  fi
  
  export NODE_PATH=./node_modules
}

I don't switch between node versions anymore, so I just use the latest LTS version.