Jest common functions

Jest common functions

Existence

getBy* and getAllBy* throw an error if nothing is found.

However, the equivalent methods queryBy* and queryAllBy* instead return null or []:

expect(getAllByTestId('collection-share-button')).toHaveLength(1);

None Existence

expect(() => getByText('your text')).toThrow('Unable to find an element');

https://stackoverflow.com/questions/52783144/how-do-you-test-for-the-non-existence-of-an-element-using-jest-and-react-testing

Expect on callback function

it("should call onItemClick with actionId", () => {
	const handleItemClick = jest.fn();
	const { getByTestId } = render(
		withThemeProvider(
			<CollectionButtonGroup
				isFollowing={true}
				isOwnCollection={true}
				onButtonClick={handleItemClick}
			/>
		)
	);

	fireEvent.click(getByTestId("collection-delete-button"));

	expect(handleItemClick).toHaveBeenCalledWith(
		CollectionButtonGroupAction.Delete
	);
});