javascript - TypeError : routingState. 等于不是函数 | Jest 测试用例

Question

这是我的selector.js 文件:-

const makeSelectLocationState = () => {
  let prevRoutingState;
  let prevRoutingStateJS;

  return (state) => {
    const routingState = state.get('route'); // or state.route

    if (!routingState.equals(prevRoutingState)) {
      prevRoutingState = routingState;
      prevRoutingStateJS = routingState.toJS();
    }

    return prevRoutingStateJS;
  };
};

以及我编写的以下测试用例:-

it('makeSelectLocationState function testing', () => {
    const selectLocationState = makeSelectLocationState();
    const mockedState = fromJS({
      route: '',
    });
    expect(selectLocationState(mockedState)).toEqual('');
  });

使用 jest 运行测试用例时出现以下错误:-

TypeError: routingState.equals is not a function

Answer 1

问题出在这里:

const routingState = state.get('route'); 

感觉您没有获得routingState，可能未定义，因此您将收到上述错误消息。因此请检查routingState的日期。

并在测试文件中，将mockedState传递给selectLocationState

selectLocationState(mockedState)

但是，makeSelectLocationState函数没有属性。也许更改为:

const makeSelectLocationState = (state) => {}