javascriptreactjsjestjsreact-testing-librarytesting-library

How do you test for the non-existence of an element using jest and react-testing-library?


I have a component library that I'm writing unit tests for using Jest and react-testing-library. Based on certain props or events I want to verify that certain elements aren't being rendered.

getByText, getByTestId, etc throw and error in react-testing-library if the element isn't found causing the test to fail before the expect function fires.

How do you test for something not existing in jest using react-testing-library?


Solution

  • From DOM Testing-library Docs - Appearance and Disappearance

    Asserting elements are not present

    The standard getBy methods throw an error when they can't find an element, so if you want to make an assertion that an element is not present in the DOM, you can use queryBy APIs instead:

    const submitButton = screen.queryByText('submit')
    expect(submitButton).toBeNull() // it doesn't exist
    

    The queryAll APIs version return an array of matching nodes. The length of the array can be useful for assertions after elements are added or removed from the DOM.

    const submitButtons = screen.queryAllByText('submit')
    expect(submitButtons).toHaveLength(2) // expect 2 elements
    

    not.toBeInTheDocument

    The jest-dom utility library provides the .toBeInTheDocument() matcher, which can be used to assert that an element is in the body of the document, or not. This can be more meaningful than asserting a query result is null.

    import '@testing-library/jest-dom/extend-expect'
    // use `queryBy` to avoid throwing an error with `getBy`
    const submitButton = screen.queryByText('submit')
    expect(submitButton).not.toBeInTheDocument()