I have a component that returns null in render under certain conditions:
render() {
if (this.props.isHidden) {
return null;
}
return <div>test</div>;
}
I want to check if the component is null when isHidden is true with jest and enzyme:
describe('myComp', () => {
it('should not render if isHidden is true', () => {
const comp = shallow(<myComp isHidden={true} />);
expect(comp.children().length).toBe(0);
});
});
This works but is there a more idiomatic way to write this test ? Testing for components that render as null is quite a common scenario.
ShallowWrapper has a isEmptyRender() function:
expect(comp.isEmptyRender()).toBe(true)
expect(comp.type()).toEqual(null)
That's it!
or:
expect(comp.get(0)).toBeFalsy()
According to ShallowWrapper::html implementation
it returns null if component instance type is null, as a result of render.
expect(comp.html()).toBeNull();