[v9] options.extensions not used

[rkostrzewski]

Bug

Please try to answer the following questions:

• What version of Neutrino are you using?
  9.0.0-rc.3
• Are you trying to use any presets? If so, which ones, and what versions?
  @neutrinojs/react@9.0.0-rc.3 (should be visible with compile-loader only)
• Are you using the Yarn client or the npm client? What version?
  npm@6.7.0
• What version of Node.js are you using?
  node@10.8.0
• What operating system are you using?
  macOS
• What did you do?

1. Run npx @neutrinojs/create-project@9.0.0-rc.3 with only React on
2. Edited .neutrinorc.js to look like this:

const react = require('@neutrinojs/react')

module.exports = {
  options: {
    root: __dirname,
    extensions: ['mjs', 'jsx', 'js', 'ts'], // <- added 'ts' extension
  },
  use: [
    react(),
  ],
}

3. Created empty src/index.ts file and removed src/index.js/
4. Run webpack --mode production

• What did you expect to happen?
  Build finishes successfully because src/index.ts is resolved by webpack and processed by babel
• What actually happened, contrary to your expectations?
  Build fails with error:

ERROR in multi ./src/index
Module not found: Error: Can't resolve '/Users/rkostrzewski/GitHub/coinsy/web/src/index' in '/Users/rkostrzewski/GitHub/coinsy/web'
 @ multi ./src/index index[0]

Based on quick investigation this might occur because options.extensions is not used in Neutrino.getOptions instead moduleExtensions variable is used that is initialised only with source from neutrino/extensions module (changing that declaration to include options.extensions yields a successful build however on v8 the code looks the same yet extension 'foo' works in v8)

[edmorley]

Hi! Thank you for reporting. Yeah this looks like a bug.

@eliperelman it seems like we should be setting the default extensions list here (rather than declaring moduleExtensions the line before):

neutrino/packages/neutrino/Neutrino.js

Lines 31 to 34 in 46793f2

	const options = {
	debug: false,
	...clone(opts),
	};

...and then referring to options.extensions (instead of moduleExtensions) here:

neutrino/packages/neutrino/Neutrino.js

Lines 83 to 91 in 46793f2

	Object.defineProperty(options, 'extensions', {
	enumerable: true,
	get() {
	return [...moduleExtensions];
	},
	set(extensions) {
	moduleExtensions = new Set(extensions.map(ext => ext.replace('.', '')));
	},
	});

We should also add some tests for this, since there currently aren't any for extensions here:
https://github.com/neutrinojs/neutrino/blob/master/packages/neutrino/test/api_test.js

Thoughts?

[eliperelman]

@edmorley it's funny you mention that, because I started doing exactly that yesterday. Then I remembered that the order of these extensions is very important, so I'm wondering if setting this in options should overwrite instead of merge?

[edmorley]

Ah yes I think it should override.

[edmorley]

@eliperelman hi :-) Did you have a WIP for this locally?

[timkelty]

@eliperelman, @edmorley If no one has a WIP of this, I can take a stab this week!

[timkelty]

Thanks for the clear bug report, @rkostrzewski. Just pushed a PR: #1477