Added function to symlink existing packages to nvm.fish

[horlarme]

This request adds another step to the installation of the plugin by checking for existing Node Release (if available) and creating a symlink from them to the nvm.fish package directory.

This is mainly useful when an existing NVM installation exists on the previous shell before fish is installed.

There is a function available _nvm_symlink_local which can also be used on request.

[jorgebucaran]

Is this compatible with normal nvm.fish usage?

[horlarme]

What do you mean by normal nvm.fish?

[jorgebucaran]

Does this support Tab-completions, nvm install, ls, use, and uninstall?

[horlarme]

I don't think I really understand the question still but at same time, no, it doesn't support listing (ls) the existing releases (if this is what you meant). It is meant to only run at installation (although could be used after installation by calling its name).

[jorgebucaran]

Well, do tab completions for nvm use, ls, etc., work as usual after symlinks are created for previously downloaded Node versions via POSIX nvm? I don't know how POSIX nvm installs Node versions exactly, so I'm surprised this actually works.

[horlarme]

Oh... Yes. Running nvm list lists the existing releases as part of the list and other actions can be done on it like nvm use, although I haven't tried remove... Will update on this. Or do you think it should have been a copy instead of symlink?

[horlarme]

I have confirmed that every other command associated with nvm.fish works with the symlinked releases.

[jorgebucaran]

Cool! Does that include Tab-completions for all commands? For example, if Node 15 is installed, nvm uninstall should be able to auto complete that version for you.

[horlarme]

Sorry for replying late, yesterday was my mother's birthday and today, I celebrated my daughters naming so I haven't really used my PC since.

Yes, there is tab completion for changing (use) a release as seen in the screenshot below

[jorgebucaran]

Thank you for taking the time to create this PR. While I appreciate the effort put into this feature, I don't think it's necessary to add it to nvm.fish at this time. Perhaps we can revisit this in the future if we hear from more users or the issue becomes more clearly defined. Thanks again for your contribution!