Unit tests on a react-redux connected HOC

react-redux-connected-hoc.js

import { compose, lifecycle } from 'recompose';
import { connect } from 'react-redux';
import { getSomeState } from '../selectors';
import { doSomething } from '../actions';

export default compose(
  connect(
    (state) => ({
      auth: getSomeState(state),
    }),
    (dispatch) => ({
      do() {
        return dispatch(doSomething());
      },
    })
  ),
  lifecycle({
    componentWillUpdate(props) {
      if (!props.foo.bar) {
        props.do();
      }
    },
  })
);

react-redux-connected-hoc.spec.js

import test from 'tape';
import React from 'react';
import { Provider } from 'react-redux';
import { mount } from 'enzyme';
import enhanceWithX, { __RewireAPI__ } from './enhance-with-x';

test('enhance with X HOC', assert => {

  assert.plan(1);

  const fakeAction = 'fake action';

  __RewireAPI__.__Rewire__('getSomeState', state => state);
  __RewireAPI__.__Rewire__('doSomething', () => fakeAction);

  let updateConnectedComponent;
  let fakeState = { foo: { bar: 'cheese' }};

  const fakeStore = {
    getState: () => fakeState,
    subscribe: (cb) => updateConnectedComponent = cb,
    dispatch: (actual) => {
      const expected = fakeAction;

      assert.equal(actual, expected,
        `given a component is enhanced with X then it should dispatch an action when the state updates`);

      __RewireAPI__.__ResetDependency__('doSomething');
      __RewireAPI__.__ResetDependency__('getSomeState');
    },
  };

  const FakeComponent = () => <p>Fake component</p>;

  const Target = enhanceWithX(FakeComponent);

  mount(<Provider store={fakeStore}><Target /></Provider>);

  fakeState = { foo: {} };
  updateConnectedComponent();

});