Cannot read property 'child' of undefined on React 16 + enzyme-adapter-react-16

[dep]

Current behavior

import React from "react";
import { mount } from "enzyme";
import NewTagModal from "./NewTagModal";

describe("New Tag Modal", () => {
  let component;
  function mountComponent() {
    return mount(
      <NewTagModal isOpen={true} />;
    );
  }

  beforeEach(() => {
    component = mountComponent();
  });

  it("has a title", () => {
    expect(component.find("h4").text()).toBe("Create New Tag");
  });
});

Returns:

    TypeError: Cannot read property 'child' of undefined

      72 |
      73 |   function mountComponent() {
    > 74 |     return mount(

      at getFiber (../../../node_modules/enzyme-adapter-react-16/src/detectFiberTags.js:15:35)
      at detectFiberTags (../../../node_modules/enzyme-adapter-react-16/src/detectFiberTags.js:76:15)
      at ReactSixtee^C

Expected behavior

Tests pass

API

• shallow
• mount
• render

Version

library	version
enzyme	3.11.0
react	16.4.0
react-dom	16.4.0
react-test-renderer	n/a
adapter (below)	enzyme-adapter-react-16

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 ( )

[ljharb]

Can you try React v16.4.2?