Upgrade Node 6.x => 8.x (LTS)

[benjaoming]

Observed behavior

The more recent Node 8 is an LTS and comes in the official Ubuntu 18.04 repos, just apt install nodejs.

Note that the LTS lifespan for 8.x will end on December 31st, 2019.

Expected behavior

Let's stay on par with an LTS

User-facing consequences

None!

Original 8.0.0 changelog:

https://github.com/nodejs/node/blob/master/doc/changelogs/CHANGELOG_V8.md#2017-05-30-version-800-current-jasnell

[indirectlylit]

I don't recall what issue we had with 8.x but it's worth a try! (refs #2054)

[rtibbles]

Note that 6.x is also an LTS (https://github.com/nodejs/Release#release-schedule) maybe we should just leapfrog to 10.x in October?

[benjaoming]

@rtibbles leapfrogging might be a big mouthful, I mean perhaps more bite-sized to do one LTS at a time? :)

But as I mentioned, Node 8 is also in Ubuntu 18.04 official repos, which is really really nice for quickly getting started.

I was also curious about the very substantial changelog for Node 8...

👍 @indirectlylit it's worth a try... IIRC, we made the last Node upgrade without issues. We did the same for KA Lite.

[indirectlylit]

All I remember is that there was a specific reason we did not allow 8.x (it caused issues in some cases)

[indirectlylit]

also for anyone finding this issue later: you can use nvm to manage multiple node versions

[jonboiser]

with node 8, we could use async functions in the test suite.

[rtibbles]

Well, we currently run the frontend tests in Chrome Headless, so we should already be able to use async functions, no?

[jonboiser]

Actually, I'm not sure anymore, since the tests files are compiled via webpack (hence buble) before sent to the browser.

I tried rewriting one of the tests with an async function and got a webpack error to that effect.

[rtibbles]

Ah, yeah - so we can't use it because buble can't transpile async, I think, so even though the browser would support it, our transpiler doesn't.

We can add:

transforms: {
  generator: false
}

to the buble config just for tests, and it seems like that might stop it from failing at least? https://gitlab.com/Rich-Harris/buble/issues/71

[rtibbles]

We can track potential integration of async into buble here too: bublejs/buble#125