expect is not defined in jest-dom

I get the following error on running npm test on my project, not created with create-react-app:

ReferenceError: expect is not defined
at Object.<anonymous> (/Users/ryedida/Desktop/threaded-messenger/node_modules/@testing-library/jest-dom/dist/extend-expect.js:7:1)
at Module._compile (internal/modules/cjs/loader.js:1256:30)
...
at require (internal/modules/cjs/helpers.js:75:18)
at Object.<anonymous> (/Users/ryedida/Desktop/threaded-messenger/src/componentTestUtils.js:1:1)

Setup

My root directory has a jest.config.js file, whose contents are

const config = {
    verbose: true,
    setupFilesAfterEnv: ['<rootDir>/src/componentTestUtils.js'],
    testEnvironment: "jsdom"
};

module.exports = config;

componentTestUtils.js has

import '@testing-library/jest-dom/extend-expect';
import React from 'react';
import { MemoryRouter, Route } from 'react-router-dom';
import { render } from '@testing-library/react';
import App from '../components/App';

and defines some functions that I use. I am using Node 14.7, npm 7.6.3, @testing-library/jest-dom 5.12.0, @testing-library/react 11.2.6. My test script in package.json is

mocha --require @babel/register --reporter progress components/*.test.js

Similar Questions/Issues

My research in this issue has led me to

• this GitHub issue in Enzyme, where a highly voted answer essentially says add the setupFilesAfterEnv key in the jest config
• this GitHub issue in jest-dom, where the recommendations to upgrade @testing-library/jest-dom and @testing-library/react don't apply since my versions are higher, and their recommendation to upgrade from Node 10 to 12 also doesn't apply. Their other recommendation to add the same key above also did not work.
• this GitHub issue in jest-native, the same setupFilesAfterEnv recommendation
• this SO question with the same issue, but I already have the import in the accepted answer.

How do I solve this error?