How to get Fish shell and NVM both installed with Homebrew to work together?

If you're using oh my fish you can install the nvm plugin (after installing NVM with homebrew).

$ omf install nvm

Then set the NVM_DIR and all should be fine.

$ set -gx NVM_DIR (brew --prefix nvm)

You can use Bass. Clone the git repository

git clone https://github.com/edc/bass.git 

Then cd in the cloned directory and type

make install
bass source ~/.nvm/nvm.sh ';' nvm use stable

Now you should be able to use node inside fish shell.

I've created the following function inside ~/.config/fish/functions/nvm.fish:

function _nvm
    bass source (brew --prefix nvm)/nvm.sh --no-use ';' nvm $argv
end

function nvm    
    if test -e $NVM_CURRENT
        echo Setting up nvm..

        _nvm use default --silent

        set -x -g NVM_CURRENT (_nvm current)

        printf "Using Node %s\n" $NVM_CURRENT
    end

    _nvm $argv
end

After having several issues with other plugins, this just works.