Undefined exported __moduleExports

[FbN]

• Rollup Plugin Name: @rollup/plugin-commonjs
• Rollup Plugin Version: 11.0.2
• Rollup Version: 1.32.1
• Operating System (or Browser): Arch Linux
• Node Version: v12.16.1

How Do We Reproduce?

Not really sure. Try to roll a mix of ES6 modules and CJS modules that require named export '__moduleExports' when your main package.js has "type": "module".

In my projectI was using snowpack (https://www.snowpack.dev/) with this configuration

/* snowpack.config.js */
module.exports = {
namedExports: {
sanctuary: ['__moduleExports'],
xstream: ['__moduleExports'],
'sanctuary-def': ['__moduleExports'],
'sanctuary-type-identifiers': ['__moduleExports']
},
rollup: {
plugins: [pluginNodeBuiltins(), pluginNodeGlobals()]
}
}

Expected Behavior

Working rolled web_modules

Actual Behavior

Exported __moduleExports is undefined

Proposed solution

Solved this way: FbN@829219e

[shellscape]

Please provide a reproduction as per the instructions in the issue template. Otherwise we cannot help.

[lukastaegert]

I think I have seen this error when an entry point that is CJS is imported by a file that ends up in another chunk.

[lukastaegert]

The error occurs in fact as soon as an entry point that is CJS is imported by a module in the graph. Self-imports count as well. Repro here: https://repl.it/@lukastaegert/rollup-plugin-repro

"type": "module" is very likely irrelevant to this issue.

[FbN]

Thank you @lukastaegert for the clarification and test. Do you think my patch is a good solution or may cause collateral damages?

[csr632]

Here is a minimal reproduce repo: https://github.com/csr632/rollup-issue

[csr632]

@danielgindi @lukastaegert
Could you take a look at this?

[csr632]

Oh, this is already fixed by latest commonjs plugin in master branch, but the fix is not published into npm yet. This issue can be closed after it is published.

[shellscape]

@csr632 Please do not post successive replies - use the Edit function on the first.

[derolf]

I just hit this problem. "__moduleExports" appears when importing files that are also entry points.

rollup v2.26.10

Error:

TypeError: undefined is not an object (evaluating '_here_reactFlutter_service.__moduleExports.invoke'))

I upgraded the versions in @lukastaegert 's repl and the problem still exists: https://repl.it/repls/CrushingNuttyLesson#package.json

The output is:

test1.js:

import test2 from './test2.js';

console.log(test2.__moduleExports);
var test1 = 1;

export default test1;

test2.js:

var test2 = {
  a: 2,
};

export default test2;

Here as an ugly workaround. It works by proxying the entry points through virtual modules: https://repl.it/repls/GainsboroUpsetComma#rollup.config.js

[ftaiolivista]

The problem still exists in snowpack using [email protected]

Some deps use import with .default creating problems.

I solved patching [email protected] to always set default to the namespace when ther is not allready a default defined.

diff --git a/node_modules/@rollup/plugin-commonjs/dist/index.js b/node_modules/@rollup/plugin-commonjs/dist/index.js
index 32dd0de..e271a8a 100644
--- a/node_modules/@rollup/plugin-commonjs/dist/index.js
+++ b/node_modules/@rollup/plugin-commonjs/dist/index.js
@@ -55,7 +55,9 @@ const HELPERS = `
 export var commonjsGlobal = typeof globalThis !== 'undefined' ? globalThis : typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};
 
 export function getDefaultExportFromCjs (x) {
-	return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;
+    return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ?
+        (x['default'].default = x.default, x['default'])
+        : x;
 }
 
 export function createCommonjsModule(fn, basedir, module) {

I think this trick is not harmful and maximize compatibility