Mocha not calling my function in my test

I have this test:

it('calls addTheItem when clicked', () => {
  const button = wrapper.find('.addBtn').simulate('click')
  expect(addTheItemStub.called).to.equal(true)
});

This is my code

<button
  className="addBtn"
  onClick={() => {this.addTheItem(inputValue); this.clearInput()}}
  >
  Add Item
</button>

This code works when I play around with it. just the test isn't passing.

also in my beforeEach:

    const addTheItemStub = sinon.spy();
    const addItemStub = sinon.spy();
    const usingEnterKeyStub = sinon.spy();
    beforeEach(() => {
      wrapper = shallow(
        <Container
          addTheItem={addTheItemStub}
          addItem={addItemStub}
          items={itemsStub}
          usingEnterKey={usingEnterKeyStub}
        />
      )
    });

I'm stubbing it out. I'm expecting the stub to be called.

but it's expecting it to be not called or false. what am i doing wrong?