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?
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()
Use queryBy
/ queryAllBy
.
As you say, getBy*
and getAllBy*
throw an error if nothing is found.
However, the equivalent methods queryBy*
and queryAllBy*
instead return null
or []
:
queryBy queryBy* queries return the first matching node for a query, and return null if no elements match. This is useful for asserting an element that is not present. This throws if more than one match is found (use queryAllBy instead). queryAllBy queryAllBy* queries return an array of all matching nodes for a query, and return an empty array ([]) if no elements match.
https://testing-library.com/docs/dom-testing-library/api-queries#queryby
So for the specific two you mentioned, you'd instead use queryByText
and queryByTestId
, but these work for all queries, not just those two.
queryByTestId
) when in fact there are two whole sets of methods, of which queryByTestId
is one specific example.
getBy* throws an error when not finding an elements, so you can check for that
expect(() => getByText('your text')).toThrow('Unable to find an element');
You have to use queryByTestId instead of getByTestId.
Here a code example where i want to test if the component with "car" id isn't existing.
describe('And there is no car', () => {
it('Should not display car mark', () => {
const props = {
...defaultProps,
base: null,
}
const { queryByTestId } = render(
<IntlProvider locale="fr" messages={fr}>
<CarContainer{...props} />
</IntlProvider>,
);
expect(queryByTestId(/car/)).toBeNull();
});
});
const submitButton = screen.queryByText('submit')
expect(submitButton).toBeNull() // it doesn't exist
expect(submitButton).not.toBeNull() // it exist
Worked out for me (if you want to use getByTestId):
expect(() => getByTestId('time-label')).toThrow()
Another solution: you could also use a try/catch
block
expect.assertions(1)
try {
// if the element is found, the following expect will fail the test
expect(getByTestId('your-test-id')).not.toBeVisible();
} catch (error) {
// otherwise, the expect will throw, and the following expect will pass the test
expect(true).toBeTruthy();
}
You can use react-native-testing-library "getAllByType" and then check to see if the component is null. Has the advantage of not having to set TestID, also should work with third party components
it('should contain Customer component', () => {
const component = render(<Details/>);
const customerComponent = component.getAllByType(Customer);
expect(customerComponent).not.toBeNull();
});
I recently wrote a method to check visibility of element for a jest cucumber project.
Hope it is useful.
public async checknotVisibility(page:Page,location:string) :Promise<void>
{
const element = await page.waitForSelector(location);
expect(element).not.toBe(location);
}
Success story sharing
getByTestId
and got the same error. And, I didn't check the FAQ, sorry. Great library! Can you modify your answer to include the `.toBeNull();queryByText
for those who want the equivalent togetByText
that is null safe