CODEWITHSUNDEEP
reactjsunit-testingenzymesinon
Bernard
Bernard

Reputation: 25

Reactjs test sinon spy mocked function returns a function and not a boolean

I'm trying to check that that formIsValid method in my InformationGatheringFormContainer component is calling one of the components props (isInfoFormValid) when executing: 

export class InformationGatheringFormContainer extends React.Component{
...
formIsValid() {
    this.props.isInfoFormValid(this.state.invalid);
}

To do that, I'm using the sinon spy function:

it('formIsValid changes the state', () => {
    const mockFunction = sinon.spy();

    const baseProps = {
        isInfoFormValid: mockFunction,
    }

    const wrapper = shallow(<InformationGatheringFormContainer {...baseProps} />);
    wrapper.instance().formIsValid();
    expect(mockFunction).to.have.been.calledOnce.equal(true);

})

I would expect it to work, however this test gives:

AssertionError: expect(received).to.equal(expected)

Expected value to equal:
  true
Received:
  [Function proxy]

Difference:

  Comparing two different types of values. Expected boolean but received function.

So the function call is indeed detected but the .to.have.been.calledOnce enzyme method does not return a boolean here apparently.

I'm new to Reactjs Unit tests, and I'm a bit lost. How can the return of the .to.have.been.calledOnce have a different type than boolean ?

Thank you in advance for your help

Upvotes: 0

Views: 907

Answers (2)

Bernard
Bernard

Reputation: 25

I also found another way to do it: 

expect(mockFunction.callCount).toEqual(1);

Upvotes: 1

Sasha
Sasha

Reputation: 5944

Looks like calledOnce is a sinon spy property, not jest's expect. So, something like:

expect(mockFunction.calledOnce).toEqual(true);

should work (if you prefer sinon).

Worth to note that jest has his own mocking mechanism:

it('formIsValid changes the state', () => {
    const isInfoFormValid = jest.fn();

    const baseProps = {
        isInfoFormValid,
    }

    const wrapper = shallow(<InformationGatheringFormContainer {...baseProps} />);
    wrapper.instance().formIsValid();
    expect(isInfoFormValid).toHaveBeenCalledTimes(1);

})

Upvotes: 0

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