CODEWITHSUNDEEP
reactjsjestjsstyled-components
zeduke
zeduke

Reputation: 120

testing a function in jest javascript

I have the following onClick function 

onClickFunction= index => () => {
  this.setState({ activeIndex: index });
}

Which is used in the following function 

getPersons= (persons) => persons
  .map((person, index) => (
     <StyledComponentHeader
        key...
        ...
        onClick={this.onClickFunction(index)}
      >
        <Styled2
          ...
        >
          {person.name}
        </Styled2>
      </StyledComponentHeader>
    ))

in my unit test I need to test the onClickFunction. currently I have something like this 

const component= (
  <StyledComponent
    persons={persons}
  />);

describe('...', () => {
  beforeEach(() => {
    wrapper = shallow(component);
});

it('testing name', () => {
  expect(wrapper).toMatchSnapshot();
  expect(wrapper.state().activeIndex).toEqual(0);
  wrapper.instance().onClickFunction(1);
  expect(wrapper.state().activeIndex).toEqual(1);
});

it returns saying that the above last except should be 0. What is the correct way to test this function?

Upvotes: 0

Views: 70

Answers (1)

Gabriele Petrioli
Gabriele Petrioli

Reputation: 196217

Since onClickFunction does not change the state, but returns a function which if called then changes the state, the logical way would be to test it with

wrapper.instance().onClickFunction(1)();

(notice the added () at the end to invoke the returned function)

Upvotes: 1

Related Questions