The Result of `unwrapExports` is Never Assigned

[ryanfitzer]

This issue was transferred from rollup/rollup-plugin-commonjs, which had no issue templates

I'm trying to bundle styled-jsx with my React comment and getting errors resulting from the unwrapExports function being called but never assigned. Here is the abbreviated output:

/* ... */

function createCommonjsModule(fn, module) {
    return module = {
        exports: {}
    }, fn(module, module.exports), module.exports;
}

/* ... */

var style = createCommonjsModule(function(module, exports) {

    Object.defineProperty(exports, "__esModule", {
        value: true
    });
    exports.flush = flush;
    exports.default = void 0;
    
    /* ... */
    
    var JSXStyle =
        /*#__PURE__*/
        function(_Component) {/* ... */}(React.Component);

    exports.default = JSXStyle;

    function flush() {/* ... */}
});

unwrapExports(style);
var style_1 = style.flush;

var style$1 = style;

As you can see, unwrapExports(style); is called, but never assigned to style$1. This results in errors when any methods of style$1 are used since its value is module.exports (via createCommonjsModule) instead of module.exports.default.

If I alter the last line to be the following, everything works as expected:

var style$1 = unwrapExports(style);

Am I possibly misconfiguring the plugin? Any pointers will be much appreciated.

[tagoro9]

I'm experiencing a similar issue when trying to use https://github.com/airbnb/react-outside-click-handler

The library's main is:

module.exports = require('./build/OutsideClickHandler');

build/OutsideClickHandler.js

Object.defineProperty(exports, "__esModule", {
  value: true
});

[...]

exports['default'] = OutsideClickHandler;

And then the generated code calls unwrapExports but without assigning the result of that call to anything:

unwrapExports(OutsideClickHandler_1);

var reactOutsideClickHandler = OutsideClickHandler_1;

[ryanfitzer]

Here is the fully built cjs file that is generated: https://unpkg.com/browse/design-system-starter@0.0.10/dist/cjs/style-d84cd230.js

As you can see on line 716, unwrapExports(style); is never assigned.

The esm version is here: https://unpkg.com/browse/design-system-starter@0.0.10/dist/esm/style-9e80a169.js (line 711).

• Repo is here: https://gitlab.com/ryanfitzer/design-system-starter/tree/v0.0.10
• Package: npm install design-system-starter@0.0.10
• Test case: https://codesandbox.io/s/hello-world-4wyhh (see pages/index.js for button component usage)

[williamscs]

I believe I am also encountering this with the 'react-multi-carousel' library. https://github.com/YIZHUANG/react-multi-carousel

main:
module.exports = require('./lib');

The lib index is TypeScript, but is generated to js as:

"use strict";
Object.defineProperty(exports,"__esModule",{value:!0});
var Carousel_1=require("./Carousel");
exports.default=Carousel_1.default;

Which results in the unassigned unwrapExports.

[williamscs]

This probably isn't the correct process, but I created a PR with a failing test which demonstrates what I believe is the intended functionality. Let me know if this is a bad assertion.

rollup/rollup-plugin-commonjs#422

[shellscape]

Hey folks. We'll be moving this issue to the https://github.com/rollup/plugins repo soon. You may see this repo go Archived before that happens, but rest assured that will happen.

[shellscape]

Just sat down to look into this issue. Within the commonjs plugin codebase, I can't find anything that would prevent the assignment that everyone is talking about. This looks like it might be a problem with Rollup core with transforms to cjs. I'll have to investigate further.

Looks like this has come up with Rollup in the past rollup/rollup#2352