jest create-react-app "transform must export a `process` function"

I'm trying to run jest on a react app created with create-react-app, however get the error: src\App.test.js ● Test suite failed to run

TypeError: Jest: a transform must export a `process` function.

  at ScriptTransformer._getTransformer (node_modules/jest-runtime/build/ScriptTransformer.js:138:15)
  at handle (node_modules/worker-farm/lib/child/index.js:44:8)

Version dependencies:

    "react": "^16.8.1",
    "react-dom": "^16.8.1",
    "react-redux": "^5.0.7",
    "react-scripts": "1.1.4",
 "devDependencies": {
    "@babel/runtime": "^7.12.5",
    "@testing-library/jest-dom": "^5.14.1",
    "@testing-library/react": "^12.1.0",
    "jest-sonar-reporter": "^2.0.0",
},

"scripts":{
..
"test": "jest",
}

Any help would really be appreciated. Many thanks.