Jest - TypeError：无法读取未定义的属性“fn”

Question

Out of nowhere, I'm having an issue when running certain Jest tests:

Summary of all failing tests
 FAIL  server/controllers/voice/settings/__tests__/voice.settings.controller.test.js
  ● Test suite failed to run

    TypeError: Cannot read property 'fn' of undefined

      at Runtime._createJestObjectFor (node_modules/jest-runner/node_modules/jest-runtime/build/index.js:734:35)
      at handle (node_modules/worker-farm/lib/child/index.js:44:8)
      at process.<anonymous> (node_modules/worker-farm/lib/child/index.js:51:3)
      at emitTwo (events.js:126:13)
      at process.emit (events.js:214:7)

I saw that someone had the same problem here ( https://github.com/facebook/jest/issues/5058 ) but I'm not sure if it ever got resolved. I tried removing node_modules and reinstalling but that didn't fix it. Wondering if anyone else has had the same error before and how it got resolved?

Answer 1

I got the same issue in my react app.So i added my jest setup.js file to

global.jQuery = require('jquery');

after that test worked fine

Answer 2

So this error actually came up since I was using node v8.9.3. After downgrading back to v6.11.1, this issue went away.