1

I have a functional react component and I want to change a property value inside the component in an enzyme unit test (in my case the ready attribute). The unit test should use shallow to avoid rendering any children components.

Here is the simplified component code:

import {useTranslation} from 'react-i18next';
// ...

const MyComponent: React.FC<IProps> = (props: IProps) => {

  const {t, ready} = useTranslation('my-translation-namespace');
  // ...

  return (
    <React.Fragment>
      {ready &&
        <div className="my-component">some more content...</div>
      }
    </React.Fragment>)
};
export default MyComponent;

And this is the corresponding test:

describe('MyComponent', () => {

  let component: ShallowWrapper;

  it('should be displayed', () => {
    component = shallow(<MyComponent/>);

    // HERE I WOULD LIKE TO SET: component.ready = true

    expect(component.find('.my-component').length).toBe(1);
  });
});

Any idea how to change the ready attribute to true in my test?

Ynnckth
  • 95
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1 Answers1

2

This can be accomplished by mocking the react-i18next module with jest.

const mockT = jest.fn((a) => a)
const mockReady = true
jest.mock('react-i18next', () => 
  jest.fn().mockImplementation(() => ({
    useTranslation: () => ({ t: mockT, ready: mockReady })
  }))
);

Take a look at the documentation or this article if you are using ES modules or this answer for other options.

edit: use module factory for second param of jest.mock instead if passing a plain object.

lastcanal
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