josdejong/mathjs

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

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#1,898 opened on Jun 28, 2020

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help wanted

Description

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.

Contributor guide

Tech stack
javascriptnodejs
Domain
testingbackend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
basic knowledge of Jestunderstanding of JavaScript modules
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate how mathjs exports its factory functions (see lib/utils/factory.js) and how Jest resolves modules. The error occurs in Complex.js line 28, suggesting a circular dependency or missing export. Check Jest configuration for module transformation and whether mathjs is properly transpiled. Consider adding a Jest transform ignore pattern for node modules or checking if mathjs needs to be included in transformIgnorePatterns.