Facing issue white writing jest test cases for a module which imports allotment.

[avanish-srivastava]

Hi

I have a react application in which I have used "allotment" in one of my component and to test the application I have used "Jest" and "react testing library". Now while testing my component which has "allotment", it is giving me this below error.

I tried this with a sample application also and there also I'm facing this same issue.
So what can be the possible reason for this issue?

Link for that sample application :- https://github.com/avanish2403/OpenfinContextSharing/tree/AppWithJestTestCases

[AndreSilva1993]

Have you tried using the transformIgnorePatterns option of Jest? https://jestjs.io/docs/configuration#transformignorepatterns-arraystring

I was also having this issue and pay attention to the extension of the file that Jest is complaining which is .mjs. So if like me, you have something like this

transform: {
  '\\.[jt]sx?$': 'babel-jest',
},

you have to change to:

transform: {
  '\\.m?[jt]sx?$': 'babel-jest',
},

[lukedukeus]

I just ran into the same issue, but was unable to fix it, so I just mocked the component.

jest.mock('allotment', () => ({
  Allotment: jest.fn().mockImplementation(({ children }) => <div>{children}</div>),
}));