Repository: create-react-app
Issue: Can't use jest.fn with CRA version 4.0.1
Labels: needs triage,issue: bug report

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### Describe the bug

When creating a react app with CRA version 4.0.1 and using jest.fn in the tests it fails.
For example if I do something like:

`const MockedComponent = jest.fn(() => <>Mocked Component</>)`

It complains with the error:

** [Error: mockConstructor(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.]**

### Did you try recovering your dependencies?
Yes, but it did not work.
I solved it by downgrading react-scripts to version 3.4.0

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yarn --version
1.22.5

### Which terms did you search for in User Guide?

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Create React App 4.0.2 jest.fn

### Environment

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  To help identify if a problem is specific to a platform, browser, or module version, information about your environment is required.
  This enables the maintainers quickly reproduce the issue and give feedback.

  Run the following command in your React app's folder in terminal.
  Note: The result is copied to your clipboard directly.

  `npx create-react-app --info`

  **current version of create-react-app: 3.4.0
  running from /home/myuser/.nvm/versions/node/v10.19.0/lib/node_modules/create-react-app

  System:
    OS: Linux 5.3 Ubuntu 18.04.5 LTS (Bionic Beaver)
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
  Binaries:
    Node: 10.19.0 - ~/.nvm/versions/node/v10.19.0/bin/node
    Yarn: 1.22.5 - /usr/bin/yarn
    npm: 6.13.4 - ~/.nvm/versions/node/v10.19.0/bin/npm
  Browsers:
    Chrome: 87.0.4280.66
    Firefox: 83.0
  npmPackages:
    react: Not Found
    react-dom: Not Found
    react-scripts: Not Found
  npmGlobalPackages:
    create-react-app: 3.4.0**
-->

(paste the output of the command here.)

### Steps to reproduce

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1. When creating a react app with CRA version 4.0.1 and using jest.fn in the tests it fails.

2.For example if I do something like:

`const MockedComponent = jest.fn(() => <>Mocked Component</>)`

3. It complains with the error:

** [Error: mockConstructor(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.]**


### Expected behavior

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Not failing.

### Actual behavior

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