将请求标头与jest-fetch-mock比较

Question

因此，我有一个动作，如果给定参数，则会在请求标头中添加“ Content-Type”。如何测试是否用jest-fetch-mock添加了“ Content-Type”？标头似乎无关紧要。

// action
export const someAction = (isFoo) => dispatch => {
  const headers = new Headers();

  if (isFoo) {
    headers.append('Content-Type', 'application/json');
  }
  
  const request = new Request(`url/api/someEndpoint`, {
    method: 'GET',
    headers
  });
  
  return fetch(request).then(
    response => {
      dispatch({ type: types.SOME_ACTION_TYPE_SUCCESS, response });
      return response;
    },
    error => {
      dispatch({ type: types.SOME_ACTION_TYPE_FAILURE, error });
      return { error };
    }
  );
};

// test
it('should run action successfully and trigger SOME_ACTION_TYPE_SUCCESS', () => {
  fetch.mockResponseOnce(JSON.stringify({foo: 'bar'}));

  const expectedActions = [
    { type: types.SOME_ACTION_TYPE_SUCCESS, response: {foo: 'bar'} }
  ];

  const store = mockStore({});

  return store.dispatch(actions.someAction(true)).then(() => {
    expect(store.getActions()).toEqual(expectedActions);
  });
});