Add null check to avoid TypeError: Cannot read properties of undefined (reading 'call')

[fregante]

Feature request

Note that this is not a bug report, this is a UX improvement ticket. It won't actually solve the underlying issue but it might help webpack users understand it better.

What is the expected behavior?

Occasionally webpack fails to properly load modules and it fails on this line, causing:

• Uncaught TypeError: Cannot read properties of undefined (reading 'call') #15582

And others like it: https://github.com/webpack/webpack/issues?q=is:issue+sort%253Aupdated-desc+%2522Cannot+read+properties+of+undefined%2522+in%253Atitle+is%253Aclosed++call

What is motivation or use case for adding/changing the behavior?

The error is in webpack's own code and it's far removed from the cause.

How should this be implemented in your opinion?

Catching the error and rewording it will help people find a solution.

A better error would look like this, including as much information as possible regarding its context

"The module sugar/free.js could not be loaded from './wood-cake.js' etc"

Are you willing to work on this yourself?

If the fix looks like this yes:

+ if (typeof __webpack_modules__[moduleId] !== 'function') {
+ 	throw new Error(`The module xyz could not be loaded`)
+ }
  __webpack_modules__[moduleId].call(module.exports, module, module.exports, __webpack_require__);

[alexander-akait]

Feel free to send a PR, but let's do it only for dev enviroment to avoid extra runtime

[aman8218]

can you provide more detail relating to this issue?