[v5] Indicate the supported Node.js version in package.json

[realityking]

I based the range on what's indicated in .travis.yml but since Travis always defaults to the newest release in each series a higher minor could be selected as well.

Especially Node.js 4.5 might be a good pick since it's the first release to support Buffer.from, Buffer.alloc and Buffer.allocUnsafe.

In #2111 I found this mention in the summary:

Moving forward we'll only be actively supporting active LTS and current Node versions. In practical terms this means Node 6+.

But it's not currently reflected in the Travis config.

Relates to #2312

[xzyfer]

What exactly is the benefit onlf using engines?

I was under the impression it wasn't encouraged by npm anymore.

Additionally we'll be dropping Node 4 for the v5 release. For readability please use caret ranges.

^6 || ^8 || ^9 || ^10

[realityking]

It's mostly machine readable documentation - npm will just print a warning, though yarn will actually error out when used on an unsupported Node.js version.

I followed your suggestion partially and changed it to ^6.9 || ^8.9 || >= 9 because

• Node.js 6.5 actually contains a few new features around ES2015 support that v5 could then use at some point of time
• Excluding Node.js 11 - which will be released in 1.5 years - seems like a bad idea.

[xzyfer]

The version choices seem arbitrary. Our support policy will be Active LTS and Current. We don't get to choose which minor/patch we choose to support because it's convenient to us.

We either

• support the whole range, ^6 || ^8` or,
• support from the specific version version a release line went LTS (usually a couple months after the initial release).

I was unable to find a list of at what specific version a release went LTS. For now please keep it at ^6 || ^8. We'll cross the JS feature bridge when we come to it.

Additionally >= 9 is too broad. We'll have dropped 9 before start supporting 11. Please stick to the suggested ^9 || ^10, it's far easier for us to delete/update without thinking.

[realityking]

Sorry, I should've mentioned how I arrived at those minor versions.

6.9 and 8.9 are the releases where those versions transitioned into LTS. See these blog posts for reference:

• https://nodejs.org/en/blog/release/v6.9.0/
• https://nodejs.org/en/blog/release/v8.9.0/

As for the second point, at least for users using yarn this would mean any user using Node.js 11 could not use node-sass without you releasing a new version.

[xzyfer]

Nice one, I was trying to find those blog post but missed it.

any user using Node.js 11 could not use node-sass without you releasing a new version

This is mostly true regardless because we wouldn't have the binaries ready.
We'd do a major bump when

• 9 transitions to maintenance, and 10 going into Active LTS (to drop 9 support)
• 10 transitions to active LTS, and 11 is released (to reduce 10 support to >= active LTS)

Users who want to live on the bleeding edge can use the --ignore-engines flag.

[realityking]

Fair point about the binaries. Changed to ^6.9 || ^8.9 || ^9 || ^10

[xzyfer]

Looks like travis was having issues. Kicked off a rebuild.

[xzyfer]

Thanks again ❤️

[saper]

I wonder if we shouldn't add this to 4.x. too - even when using node 10 yarn has no way of knowing it needs to install newer version than specified