TypeError: Cannot read property 'prototype' of undefined when run in jest

[junbujianwpl]

yarn jest --testPathPattern path/to/file
yarn run v1.22.4
$ D:\workspace\js\myproject\node_modules\.bin\jest --testPathPattern path/to/file
 FAIL  path/to/xxx.spec.ts
  ● Test suite failed to run

      ● Test suite failed to run

        TypeError: Cannot read property 'prototype' of undefined

      at Object.<anonymous>.createComplexClass.isClass (node_modules/mathjs/lib/type/complex/Complex.js:28:23)
      at assertAndCreate (node_modules/mathjs/lib/utils/factory.js:49:12)
      at Object.<anonymous> (node_modules/mathjs/lib/entry/pureFunctionsAny.generated.js:24:38)
      at Object.<anonymous> (node_modules/mathjs/lib/entry/mainAny.js:53:25)

It can be produced with the latest at least three versions. It works fine in my project when run the project by running npm run start. Why this is not working with jest.

[josdejong]

Thanks for reporting. How can I reproduce this issue?

[Git-on-my-level]

I was able to reproduce this, it involves configuring jest module resolution using the moduleDirectories key in jest.config.js
I created a minimal reproducible repo here:
https://github.com/Git-on-my-level/mathjs-jest-issue-1898

[Git-on-my-level]

My fix was rather than including . as a target in moduleDirectories I had to explicitly list all my directories or use moduleNameMapper instead

Example

Instead of

module.exports = {
  moduleDirectories: ["node_modules", "."],
};

Replace with

module.exports = {
  moduleDirectories: ["node_modules"],
  moduleNameMapper: {<map module resolutions here instead>},
};

I'm not familiar enough with jest to root cause this, but hope this helps

[josdejong]

Thanks a lot for working out this example David!

We're working on improved support for ES modules and Commonjs in the library (see #1941, #1962), it will be interesting to see if we can solve this issue with Jest (or maybe it's even already fixed in this PR).

[josdejong]

mathjs v8 was released a few days ago. This improved ES modules support which also gave trouble with Jest.

Can anyone see if this issue still occurring in v8?

[Git-on-my-level]

Using my above repo but updating mathjs to 8.0.1 still results in the same error

[josdejong]

Thanks for checking 👍

We'll keep this issue open and have to do more digging then. Anyone able to help?