Testing react-redux

[arhtudormorar]

Hi! I am using react-redux in one of my npm packages (the package is using react-redux). How would I go about testing my app?

Below is a reference to the same problem:

          I have the same issue with "react-redux".

 • Test suite failed to run

    Jest encountered an unexpected token

    This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.

    [...]

    Details:

    ***\node_modules\react-redux\es\connect\connect.js:5
    import connectAdvanced from '../components/connectAdvanced';
    ^^^^^^

    SyntaxError: Unexpected token import

      4 | import LoginMethodComponent from './LoginMethodComponent';
      5 | import { startPollUpdateBankIDStatus } from '../../../redux/modules/bankID/userBankIDReducer';
    > 6 | import connect from 'react-redux/es/connect/connect';
        | ^
      7 | import { bindActionCreators } from 'redux';
      8 |
      9 | export class LoginMethodContainer extends React.Component {

      at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:403:17)
      at Object.<anonymous> (src/components/user/login/LoginMethodContainer.js:6:1)
      at Object.<anonymous> (src/components/user/login/__tests__/LoginMethodContainer.test.js:3:1)

The temporary fix for now seems to be to specify "transformIgnorePatterns" as mentioned above:

"scripts": {
    ...
    "test": "react-scripts test --transformIgnorePatterns \"node_modules/(?!(react-redux))/\"",
    ...
  },

Originally posted by @jangerhard in #5241 (comment)