Cannot use `mount`

Current behavior

Test.js

beforeEach(() => {
  wrapper = mount(<div />);
});

Terminal output

TypeError: Cannot read property '_reactInternalFiber' of null

      11 |
      12 |   beforeEach(() => {
    > 13 |     wrapper = mount(<div />);
         |               ^
      14 |
      15 |     console.log(wrapper.debug());
      16 |   });

      at _reactInternalFiber (node_modules/enzyme-adapter-react-16/src/detectFiberTags.js:15:15)
      at getFiber (node_modules/enzyme-adapter-react-16/src/detectFiberTags.js:76:15)
      at ReactSixteenAdapter.createMountRenderer (node_modules/enzyme-adapter-react-16/src/ReactSixteenAdapter.js:396:19)
      at ReactSixteenAdapter.createMountRenderer [as createRenderer] (node_modules/enzyme-adapter-react-16/src/ReactSixteenAdapter.js:702:51)
      at new ReactWrapper (node_modules/enzyme/build/ReactWrapper.js:132:30)
      at mount (node_modules/enzyme/build/mount.js:21:10)
      at Object.beforeEach (src/components/misc/ScrollToTop/ScrollToTop.test.js:13:15

Expected behavior

It should mount and run

Your environment

macOS 10.14.4 (18E226) VSCode 1.34.0 (1.34.0)

Used create-react-app to build app

API

• shallow
• mount
• render

Version

library	version
enzyme	3.9.0
react	16.8.6
react-dom	16.8.6
react-test-renderer	16.8.6
adapter (below)	1.13.1

Adapter

• enzyme-adapter-react-16
• enzyme-adapter-react-16.3
• enzyme-adapter-react-16.2
• enzyme-adapter-react-16.1
• enzyme-adapter-react-15
• enzyme-adapter-react-15.4
• enzyme-adapter-react-14
• enzyme-adapter-react-13
• enzyme-adapter-react-helper
• others ( )

---

Just to note, shallow(<div />) works just fine, however I need deeper access in this one test.

[alexmccabe]

Okay so it turns out I was mocking react-dom in a really bad way. A copy/paste jobber from StackOverflow. I have other problems to solve now, but this was not your libraries fault.

[alexmccabe]

Tried on a blank create-react-app and everything worked just fine, but as soon as I copied my components over it broke hard. Not entirely sure what’s going on here, I didn’t install any of the extra dependencies aside from react-router-dom, just ran the same test.