Switch Node version automatically using package.json(engines) or .nvmrc or .node-version

.zshrc

# place this after nvm initialization!
autoload -U add-zsh-hook

load-nvmrc() {
  local node_version="$(nvm version)"
  local nvmrc_path="$(nvm_find_nvmrc)"
  
  # Get node version from package.json engines section (remove 'v' if present)
  local package_json_node_version="$([ -r package.json ] && cat package.json | jq '.engines.node' --raw-output)"
 
  if [ "$package_json_node_version" != "null" ] && [[ ! -z "$package_json_node_version" ]]; then
     echo "Found package.json engines section with node version $package_json_node_version. This takes precedence over .nvmrc"
     
     local nvmrc_node_version_from_engines=$(nvm version "$package_json_node_version")
     
     if [ "$nvmrc_node_version_from_engines" = "N/A" ]; then
       nvm install "$package_json_node_version"
     elif [ "$package_json_node_version" != "$node_version" ]; then
       nvm use "$package_json_node_version"
     fi
     
  elif [ -n "$nvmrc_path"  ]; then
     local nvmrc_node_version=$(nvm version "$(cat "${nvmrc_path}")")

     if [ "$nvmrc_node_version" = "N/A" ]; then
       nvm install
     elif [ "$nvmrc_node_version" != "$node_version" ]; then
       nvm use
     fi
  elif [ "$node_version" != "$(nvm version default)" ]; then
    echo "Reverting to nvm default version"
    nvm use default
  fi
}
add-zsh-hook chpwd load-nvmrc
load-nvmrc

TODO: check .node-version file (package.json > .nvmrc > .node-version)

If you use Bash, do the following to have a similar 'hook' system: https://gist.github.com/laggardkernel/6cb4e1664574212b125fbfd115fe90a4