Failing resolving a module at runtime

[indiketa]

Bug report

What is the current behavior?
Webpack compilation finishes without any error nor warning.
At runtime an error is thrown while importing a module through a dynamic import.

"User-space" code router.js:259:

pantalla = await import(
  /* webpackChunkName: "generales" */
  /* webpackMode: "lazy-once" */
  `pantallas/generales/${idPantalla}.js`);

The following error is thrown:

  router.js:368 TypeError: __webpack_require__.t is not a function
    at |chunkName: generales|groupOptions: {}|namespace object:20:1
    at async cargarPantalla (router.js:259:1)

This is the webpack-generated function causing the error:

function webpackAsyncContext(req) {
	return webpackAsyncContextResolve(req).then(id => {
		return __webpack_require__.t(id, fakeMap[id] | 16);
	});
}

t does not exist into __webpack_require__.
A needed function is deleted while compiling/optimizing or mangling is not working properly, i don't know.

What is the expected behavior?
The function should exist, this is an error into webpack module resolution code. No clues or workarounds.

Other relevant information:
webpack version: 5.70.0
Node.js version: 16.14
Operating System: Fedora 35
Additional tools: --

[vankop]

could you provide a reproducible repo?

[indiketa]

Obviously it only fails in one of the several projects I use in webpack, I can't publish all the source code.

All these plugins are used:

    "devDependencies": {
        "clean-webpack-plugin": "^4.0.0",
        "css-loader": "^6",
        "css-minimizer-webpack-plugin": "^3",
        "eslint": "^8",
        "eslint-webpack-plugin": "^3",
        "html-loader": "^3",
        "html-webpack-plugin": "^5.5",
        "mini-css-extract-plugin": "^2",
        "sass": "^1",
        "sass-loader": "^12",
        "string-replace-loader": "^3",
        "style-loader": "^3",
        "terser-webpack-plugin": "^5",
        "webpack": "^5",
        "webpack-bundle-analyzer": "^4",
        "webpack-cli": "^4"
    },

Our approach will be to disable plugins/loaders one by one to detect which is causing the issue (maybe the source... but in webpack4 works perfectly).

Is there any way to disable webpack generated code obfuscation/mangling for debugging purposes?

[indiketa]

I think i've narrowed the error in the webpack dynamic import module. Preparing a minimal example repo...

[indiketa]

The issue is:
When a module exports nothing inside a dynamic import chunk, loading another module inside the chunk will make entire loading fail.

See this repo:
https://github.com/indiketa/webpack5-dynamic-import-issue.git

[vankop]

thanks. I found problem.