testing redux thunk middleware

actions.js

export const doTheThing = () => (dispatch, getState) => {
  const users = getState();
  dispatch({
    type: 'THE_THING',
    users,
  });
};

test.js

import expect from 'expect';



describe('doTheThing', () => {
  
  it('should return a function', () => {
    expect(doTheThing()).toBeA('function');
  })
  
  it('dispatch a doTheThing action', () => {
    const getState = () => ({users: 'foo'});
    const dispatch = expect.createSpy();
    doTheThing()(dispatch, getState);
    expect(dispatch).toHaveBeenCalledWith({type: 'THE_THING', users: 'foo'});
  })
  
});

PS: This might also be useful! reduxjs/redux#546