displayName for components not set during testing

[demeralde]

Is this a bug report?

Yes.

Environment

1. react-scripts-ts version: react-scripts-ts@4.0.8
2. node -v: v8.10.0
3. npm -v: 6.4.1
4. yarn --version: 1.10.1
5. enzyme version: 3.7.0
6. enzyme-adapter-react-16 version: ^1.6.0

Operating system: Ubuntu 18.04.1

Steps to Reproduce

1. Create a functional React component:

import React from 'react';

export const TestComponent = () => (
  <div>
    test
  </div>
);

2. Create a test for the component:

console.log(component.debug());
console.log(TestComponent.displayName);
expect(component.find('TestComponent')).toHaveLength(1);

Expected Behavior

Enzyme should be able to find the component using its displayName (TestComponent).

Actual Behavior

Enzyme can't find the component because it doesn't have a displayName. The output of debug() prints <Component /> instead of the component's actual name.

Other notes

This works fine during development; if I inspect my React tree using React Developer Tools the component name shows correctly. The displayName just isn't being set during testing.

Let me know if you need more details. Thanks!