FR: Notify on newer version of node.

[hemanth]

Say the current default version in the users machine is v5.1.0 and the remote latest is v5.2.0, it would be nice have a notification system in place which would indicate the user that a greater version is available.

We could indicate this when the user invokes nvm or node -v.

//cc @ljharb

[ljharb]

nvm's primary purpose isn't to keep users on the latest node, it's for being able to test in multiple versions of node at once.

I'd be fine adding an nvm command that prints all the available remote versions of node/io.js that are greater than the current one, but doing that every time nvm is invoked is way too expensive, and wrapping node is a non-starter.

[hemanth]

Cool, say we decide upon a flag for this, all we need to do is list all the versions that are greater that nvm_ls_current from nvm_ls_remote, using semver diff, does that makes sense?

[ljharb]

it wouldn't be a flag, it'd be an nvm subcommand, but sure.

[arrowrowe]

The following seems to work, but it is ugly...

nvm ls-remote | awk 'BEGIN{x=0}{if($2==""){v[x]=$0;x++}else{x=0}}END{if(x>0){for(i=0;i<x;i++){print v[i]}}else{print "No Newer Found"}}'

UPDATE: it actually regards the current version as the newest version. And it does NOT work for iojs.

How it works: output all lines after the last line with -> prefix, i.e. the current version. I didn't realize that there is at most one ->.

[ljharb]

@arrowrowe I'm not sure how that works at all, since it's not using nvm ls or nvm current anywhere

[arrowrowe]

re @ljharb: thanks to nvm ls-remote outputting a -> for installed versions. That's what $2=="" checks.

[ljharb]

ah, interesting. what if i'm on iojs and want to know if there's a newer one of those? or what if i want a newer in the same line? ie, i'm > 1.0 and i want to know if it's a newer minor, or < 1.0 and want to know if there's a newer patch.

In other words, I think that by default it should indicate ^, and optionally should indicate *

[arrowrowe]

My mistake for the iojs case. btw I just realized -> is not for installed but current version, which is another mistake 😢

Maybe more than a line is necessary here.

[arrowrowe]

@ljharb well this should work.

$ alias nln='awk '"'"'BEGIN{x=0}{if($2==""){v[x]=$0;x++}else{x=0}}END{if(x>0){for(i=0;i<x;i++){print v[i]}}else{print "No Newer Found"}}'"'"''

# Suppose iojs-v2.3.2 is installed, want newer major / minor / patch
$ nvm ls-remote iojs | nln
    iojs-v2.3.3
    iojs-v2.3.4
    iojs-v2.4.0
    iojs-v2.5.0
    iojs-v3.0.0
    iojs-v3.1.0
    iojs-v3.2.0
    iojs-v3.3.0
    iojs-v3.3.1

# No newer major
$ nvm ls-remote iojs v2 | nln
    iojs-v2.3.3
    iojs-v2.3.4
    iojs-v2.4.0
    iojs-v2.5.0

# Only newer patch
$ nvm ls-remote iojs v2.3 | nln
    iojs-v2.3.3
    iojs-v2.3.4

And similar for node cases.

But still it feels no good. Looking forward to nvm ls-remote ^4.2.2 etc. like npm semver calculator.

[ljharb]

I'm even thinking (ignore the naming) nvm newer-version ^ and nvm newer-version * which pivots on current - and if there's no current or it's system, then it would just grab the latest installed local version as "current". Perhaps also nvm newer-version ^ 4 etc to override.