If you are building your application with react and you are seeing the error:
"module parse failed: Unexpected token"
due to the use of Optional Chaining in the object path ( e.g. process.env?.JEST_WORKER_ID ), see the example below:
To resolve the issue please add react-scripts version 4.0.3 to the devdependency of the package.json.
Also in the package.json broswerlist should add the following to the browserslist section:
"not op_mini all"