Naw, it has to do with tree-shaking imports. webpack might have a different option for what you describe – if not, most linters certainly do.

`sideEffects` explicitly tells webpack whether it's safe to remove unused exports from a module, because it's always possible that code relies on them implicitly.

EDIT: I'm just going to link to the official docs (which don't mention `sideEffects` yet) because my last example was slightly wrong: https://webpack.js.org/guides/tree-shaking/#caveats

To work around the caveat mentioned in the docs above, the module author can include `sideEffects: false` in their package.json to notify webpack that excluding certain code is safe.

As an example, I just built a file that does:

    import { compose } from 'redux';
    console.log(compose);

`compose` is a really tiny no-dependency utility from Redux. The resulting bundle is 2.12 KiB. That's because webpack isn't sure whether all the other stuff exported from Redux causes any side-effects.

If I edit Redux's `package.json` to specify `sideEffects: false` and rebuild, the bundle size goes down to 799 bytes: only `compose` itself is included! There are pull requests happening all across the JS ecosystem to add this flag to popular dependencies.

See this issue for more details: https://github.com/webpack/webpack/issues/2867