Post install hook

[roberttod]

• NVM_POST_INSTALL env variable is executed after nvm install if it is set
• A fairly unopinionated change that would be a nice way to allow global node modules to be installed after a new node version is installed, as discussed in Autotomatic reinstall-packages across node versions #977

Using the hook install global npm modules

Just add the NVM_POST_INSTALL variable to .bash_profile, installing global modules that are used frequently.

export NVM_DIR="$HOME/.nvm"
export NVM_POST_INSTALL="npm install -g serve webpack standard"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" # This loads nvm

[roberttod]

If this is likely to be accepted I can add it to the readme, showing how to use it to install global node modules.

[ljharb]

Thanks for the exploratory PR.

I'm not yet decided on whether it's better to allow a generic hook - or whether it's better to just allow a default --reinstall-packages-from (via an env var).

[ljharb]

this should probably run in a subshell so that it can't interfere with nvm's operation

[roberttod]

I find the --reinstall-packages-from option pretty useful but from what I have seen, developers seem to have a bunch of global modules they use all the time and then a few that have been installed for a particular task or project that aren't really used very often.

I think having a specified set of global modules is nice and would prevent every node version having global modules you don't really use that often.

If there was a default --reinstall-packages-from I would setup an install specifically to contain my common global modules, then switch to that node version using nvm use to add or remove global modules that would be installed when I nvm install. That seems a little more complicated though.

[ljharb]

It certainly would be more complicated for your use case - but most importantly, it would be less rife for abuse than a generic hook :-/ I'll think on it more.

[augbog]

@ljharb just wondering if there were any more thoughts on this? Personally feel like its a useful feature

[ljharb]

I'm still concerned with the potential for abuse, compared with the low-cost current requirement to do nvm install X && $POST_INSTALL_COMMAND manually.

[roberttod]

The post install allows us to setup installing global modules pretty easily though, without much thought. It would be useful to do it that way rather than remembering to do it after every install.

[ljharb]

Once your global packages are set up once, nvm install X --reinstall-packages-from=Y covers it all in one go tho.

[ljharb]

@roberttod it seems like #1463 might cover your use case a bit better?