web/node: Easier targeting via options.targets

[timkelty]

It is currently rather verbose to override the targets.browsers option for babel-preset-env, and it requires you to overwrite the whole options object rather than just specifying browsers: https://neutrino.js.org/presets/neutrino-preset-web/#preset-options

This PR adds options.browsers to be able to specify directly.

Furthermore, when babel-preset-env@7.0 is released (currently at beta.32), this will make it easier for users that want to use a browserslist config file, as the new version of babel-preset-env will look for those automatically. In that case, we can support passing false or undefined to have babel-preset-env/browserslist do its thing.

[eliperelman]

The reason I have shied away from doing something like this has to do with parity of the Node.js preset. The phrase targets applies to both. Maybe I'm over-thinking this too, and it's OK to have a browsers option for web and a node option for node.

Using targets gives a common configuration, with the tradeoff being more verbose nesting/more complex nesting:

['@neutrinojs/web', {
  targets: {
    browsers: [/* ... */]
  }
}]

['@neutrinojs/node', {
  targets: {
    node: /* ... */
  }
}]

Using browsers/node gives a simpler and more targeted configuration per preset, with the tradeoff being a divergent configuration, which isn't really a problem:

['@neutrinojs/web', {
  browsers: [/* ... */]
}]

['@neutrinojs/node', {
  node: /* ... */
}]

[timkelty]

Yeah I'd be fine with just exposing options.targets instead. In which case, we should add the option to both node and web preset. Do you agree?

[eliperelman]

Let's get some more opinions. @mozilla-neutrino/core-contributors any thoughts?

[timkelty]

I like the idea of maintaining parity with @neutrinojs/node.

I updated my PR to pass targets instead - to both node and web.

[eliperelman]

This looks good to me. @mozilla-neutrino/core-contributors anyone else have any concerns?

[eliperelman]

@timkelty could you also add this option to the docs?

[timkelty]

Will do.

[timkelty]

Docs updated.

[eliperelman]

Hmm, there is no more presetEnv here, must be a typo. Can you update this to:

babel: {
  presets: [
    ['babel-preset-env', {

?

[timkelty]

Ah yep - I wondered about that.

[eliperelman]

Looks good! As soon as we get that existing typo fixed, we can merge this.

[edmorley]

Good idea! I was only thinking the other day that our configs were pretty verbose just to specify a reduced set of targets.

So long as the docs/ and packages/ copy of the docs are in sync this looks great :-)

[timkelty]

Docs are fixed!