Indicate node version support in package.json

[asheemmamoowala]

The npm package.json (and yarn) both support the engine field to indicate supported versions of Node.

Use this field to indicate what node versions are supported for this project.

cc @ahk

[mourner]

I think we shouldn't. The engines field is meant primarily for Node packages, where installing one as a dependency with an unsupported Node version means you can't use it. In our case, even if we, say, switch to Node v12+ for GL JS development, we still want to allow users on Node of any version (including older ones) to install mapbox-gl-js as a dependency for bundling without any warnings, regardless of development requirements of mapbox-gl-js for contributors.

[mourner]

We should definitely update instructions in CONTRIBUTING.md though — they're definitely very outdated (mentioning Node v4 etc.) 😅

[ahk]

It's frustrating that there is no equivalent of "engines" for the dev side of a package.json. I guess this is complicated by the fact that our project runs in three environments: Browser as library, Node.js as library (rare), and Node.js as contributor. There is no way to configure these environments separately. This seems especially troubling for the web usage where users are basically left with "It should work in a browser". I'm still a little sad that we don't have some kind of support within package.json for the (now deprecated) bower use case (pre-built web browser libraries served via NPM and possibly re-buildable with node build tools).

[jingsam]

Unifying node version is useful for the consistency of develop environment. I think it's OK to set engines field in package.json. As npm states:

this field is advisory only and will only produce warnings when your package is installed as a dependency.

So if developers install mapbox-gl-js in older node, it will functional well with some advisory warnings. That means mapbox-gl-js will work on this node but not the best one.

Note that current setting is >=6.4.0, I think it would be better to use node 8.

[asheemmamoowala]

Note that current setting is >=6.4.0, I think it would be better to use node 8.

I should've looked to see if it exists already. This ticket resulted from anecdotal mentions that v10+ doesn't work with the project. I'll update the engines field if clear min/max node version constraints exist.

[mourner]

anecdotal mentions that v10+ doesn't work with the project

I used v10 for the last year while developing GL JS without issues. v12 also works without problems after #8443.

So if developers install mapbox-gl-js in older node, it will functional well with some advisory warnings.

These warnings can be both confusing and annoying if the engines range is too specific. I'm good with setting >=8 because v6 reached end of life anyway, but not more specific that that.

[asheemmamoowala]

I used v10 for the last year while developing GL JS without issues. v12 also works without problems after #8443.

👍 I upgraded to v10.16.0 today, but had to rebuild headless-gl. It wasn't trivial to figure out. Finally worked by upgrading to the latest yarn (1.17.3) which includes a fix to rebuild native modules when the node version has changed.

[mourner]

So if developers install mapbox-gl-js in older node, it will functional well with some advisory warnings.

Also not all clients follow the "advisory" comment. E.g. Yarn throws an error unless you specify --ignore-engines:

error mapbox-gl@1.1.1: The engine "node" is incompatible with this module. Expected version ">=8.16.0".
error Found incompatible module