If you have multiple projects in your computer, it’s probable that all of them use a different version of NodeJS. For this reason, there are packages like NVM (Node Version Manager) that allow you to do exactly that, handle different versions of NodeJS without too much extra configuration.

Its installation and use are tremendously basic, just need to run nvm help if you need more help.

In order to have a better organization, it is recommended to have a .nvmrc file (must be in the root of the project) with the version that we want to use.

Its creation it’s really easy:

$ echo "14.5.0" > .nvmrc

$ echo "lts/*" > .nvmrc # to default to the latest LTS version

$ echo "node" > .nvmrc # to default to the latest version

Now, there are 2 different ways to use this file:

Manual switch

Go to you folder’s project and run nvm use, you should see something like:

Found '/Users/srhart/Projects/project/.nvmrc' with version <14.5.0>
Now using node v14.5.0 (npm v6.14.5)

Automatic switch

When you cd into your project nvm automatically will detect your .nvmrc and will use that NodeJS version.

Put this into your $HOME/.zshrc to call nvm use automatically:

autoload -U add-zsh-hook
load-nvmrc() {
  local node_version="$(nvm version)"
  local nvmrc_path="$(nvm_find_nvmrc)"

  if [ -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

Friendly reminder: place the previous code after nvm initialization!

These are the instructions for bash and fish

If a project does not have the .nvmrc file, nvm will use the default version of your system.

RTFM! :)