Packages: Always publish main and module distributions

[gziolo]

Description

Reported by @Shelob9:
I'm getting an error when importing the data package, or requiring it. I'm using create-react-app.

const data = require( '@wordpress/data' ); and import { data } from '@wordpress/data'; result in Jest throwing an error like this:

/caldera-grid/node_modules/@wordpress/data/src/index.js:4
    import { combineReducers, createStore } from 'redux';
           ^
    
    SyntaxError: Unexpected token {

The issue was on my side. I didn't set main and module inside package.json files properly. This PR fixes it.

How has this been tested?

npm run dev and npm run build still work properly.

@youknowriad, can you confirm that postcss-themes still works as expected?

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.

[ntwb]

As an aside, the npm-package-json-lint rule 'require-module': 'on', sould be added to #7001

[aduth]

As an aside, the npm-package-json-lint rule 'require-module': 'on', sould be added to #7001

What about where we don't want to use module ? Or a built main ? See also WordPress/packages#124 . Should we just not support this?

[ntwb]

What about where we don't want to use module ? Or a built main ? See also WordPress/packages#124 . Should we just not support this?

Fair call, I based my comment on the issue title "Always publish main and module distributions"

I couldn't find the reference but there was a brief discussion someplace on re-introducing and standardizing all packages in a /src folder and building out to /build.

[gziolo]

I agree that module should be optional. In fact, I removed module entry from package.json files from both packages which are not meant to be executed in the browser.