ts-jest not importing modules correctly (i.e. classnames)

[ashok-sc]

• Issue

When importing classnames package ts-jest fails and states classnames is not a function. However, it works fine using ts-node or tsc.

• Expected behavior

ts-jest should import modules just like ts-node or tsc.

• More details

1. I have a component called Title which has the following import:
   import * as classnames from 'classnames'

2. The function classnames is used in the component like so:
   classnames('title', this.props.className)

3. The app runs/compiles fine using ts-node or tsc.

4. Create a Jest snapshot test with the following code:

import { Title } from 'content';
import renderer from 'react-test-renderer';

describe('title', () => {
  const title = renderer.create(<Title />);
  expect(title.toJSON()).toMatchSnapshot();
});

1. The test fails with the following error:
   TypeError: classnames is not a function

The way to fix the test is to change the import in the Title component to:
import classnames from 'classnames'.

However this breaks running/compiling the app with ts-node or tsc.

[ashok-sc]

Ok, wow I literally just figured this out. Simply disable babel imports at the top level jest config:

"globals": {
      "ts-jest": {
        "skipBabel": true
      }
    },