Add .nvmrc support to auto

[shadowspawn]

There are occasional requests for .nvmrc support. With the addition of auto, and also looking at engines support (#618), there is now somewhere to put another target to look for.

• change directory hook shell integration auto-checking .nvmrc  #573 (comment)
• Use .nvmrc with n #547
• Add support for lts version name i.e. "argon" or "latest-argon" #423 (comment)

[shadowspawn]

https://github.com/nvm-sh/nvm#nvmrc

The contents of a .nvmrc file must be the <version> (as described by nvm --help) followed by a newline. No trailing spaces are allowed, and the trailing newline is required.

https://github.com/nvm-sh/nvm/blob/7b3af45cf73196c0a9e7ea418aee0fc8272811d0/nvm.sh#L2387

Note: <version> refers to any version-like string nvm understands. This includes:
        - full or partial version numbers, starting with an optional "v" (0.10, v0.1.2, v1)
        - default (built-in) aliases: node, stable, unstable, iojs, system
        - custom aliases you define with `nvm alias foo`

Additional info on built-in aliases and lts:

• https://github.com/nvm-sh/nvm#usage
• https://github.com/nvm-sh/nvm#long-term-support

[jasonkarns]

FWIW: there is a (not heavily used) plugin for nodenv that adds support for respecting nvmrc files: https://github.com/ouchxp/nodenv-nvmrc

We've found plugins to be a favorable way for people to extend nodenv with functionality that we don't believe should be in core, but has heavy requests by small groups of users.

[shadowspawn]

Thanks for info @jasonkarns

[shadowspawn]

I have a first cut at implementation and reasonably happy with it so far.

[shadowspawn]

I have released support in nvh first.

• https://github.com/shadowspawn/nvh

Give it a try if you are keen! Comments welcome here in this thread, or open an issue there.

e.g. nvh install auto

[shadowspawn]

FYI: @spences10 @adrianmcli @MarkLyck @ha404

[shadowspawn]

Released in v6.7.0