Update option docs for --externals (default peerDependencies & dependencies)

[gtrufitt]

Just a small clarification that the externals default is peerDependencies and dependencies.

(Not sure if this is needed as obviously this is a sensible default, but it wasn't clear until checking the code that we didn't need to have externals that mirrored peerDependencies like you might if setting up rollup from scratch)

microbundle/src/index.js

Line 406 in ded90ac

external = external

[developit]

This is a nice helpful tip!

My only nit would be that I think modules passed via --external are marked as external in addition to deps/peerDeps, rather than those being an overridable default (I may be misremembering).

[gtrufitt]

Thanks @developit

So it looks like the default is some stdLib stuff, peerDep and deps.

If the option.external is set then it's the (comma separated) external entries, stdLib and just peerDeps?

The options.entries being the other stickler, which maybe is not important to call out in the default in docs?

Hence, my assumption for a minimal but useful default, if external isn't set, in docs was 'peerDependencies and Dependencies' - but happy to push a change if you think there's more needed?

let external = ['dns', 'fs', 'path', 'url'].concat(
		options.entries.filter(e => e !== entry),
	);

const peerDeps = Object.keys(pkg.peerDependencies || {});
	if (options.external === 'none') {
		// bundle everything (external=[])
	} else if (options.external) {
		external = external.concat(peerDeps).concat(options.external.split(','));
	} else {
		external = external
			.concat(peerDeps)
			.concat(Object.keys(pkg.dependencies || {}));
	}

[wardpeet]

This is great! We might want to show while outputting in verbose mode or something which packages are being externalized but for this PR it looks 👍

[gtrufitt]

👍

[krobing]

I think the externals added as other more, should be in addition to deps/peerDeps.

My only nit would be that I think modules passed via --external are marked as external in addition to deps/peerDeps, rather than those being an overridable default (I may be misremembering).
-
@developit