TypeError: Cannot read property 'target' of null

Question

Having following code:

  it('componentDidUpdate should mount and change props', () => {
    const onChange = jest.fn();
    const wrapper = enzyme
      .mount(
          <JsonInput
            onChange={onChange}
            onValueChange={mockOnValueChange}
            value={exampleJsonStringValidated}
          />,
          { wrappingComponent: withTestThemeWrapper },
      );
    expect(wrapper.find(JsonInput).hasClass(':valid')).toEqual(false);
    wrapper.setProps({ value: exampleJsonStringNotValidated });
    expect(wrapper.find(JsonInput).hasClass(':invalid')).toBe(false);
  });

Gave me:

TypeError: Cannot read property 'target' of null

I was trying to pass onChange as onChange and onChange() but does not work.

I would appreciate any help.

I don't think `:valid` and `:invalid` [are valid class names](https://stackoverflow.com/a/449000/12251171). — , Oct 28 '19 at 12:00
Thanks for comment! I was checking with: "expect(wrapper.find(JsonInput).hasClass('valid')).toEqual(false);" but still the same error. — Tomasz Waszczyk, Oct 28 '19 at 12:12
Are you sure this is the part of code that throws this error? — Aykhan, Oct 28 '19 at 12:45
This line throws the error: wrapper.setProps({ value: exampleJsonStringNotValidated }); — Tomasz Waszczyk, Oct 28 '19 at 12:48

score 0 · Answer 1 · answered Oct 31 '19 at 10:21

0

Try:

wrapper.props().value = exampleJsonStringNotValidated;

If not, I would appreciate it if you post your component code and the props.

answered Oct 31 '19 at 10:21

Zaki Obeid

61
3

TypeError: Cannot read property 'target' of null

1 Answers1