[Request] Add --install-if-missing to fnm exec ?

[jcayzac]

I'm calling fnm directly and not using a shell environment. This means fnm use fails because it can't find the environment it depends on. I would love being able to pass --install-if-missing directly to fnm exec, e.g.

$ fnm exec --using="v10.24.1" --install-if-missing -- node --version
Installing Node v10.24.1 (x64)
v10.24.1
$ fnm exec --using="v10.24.1" --install-if-missing -- node --version
v10.24.1
$ fnm exec --using="v10.24.1" --install-if-missing -- node --version
v10.24.1

[rafasoares]

I'd also love this for fnm env --use-on-cd.

Alternatively, supporting a ~/.fnmrc with default arguments would also go a long way with these workflow-specific requirements. (sorry if it's already a feature, I didn't see any mention of it in the docs)

[ricardobeat]

It's surprising that this isn't default behaviour.

As it is, cd-ing into a directory after .nvmrc has changed just errors out with "Requested version vx.x.x is not currently installed" and break stuff, making use-on-cd a lot less useful.