使用runSaga进行延误和延误测试

Question

如果我有这样的传奇故事：

function * sagaWorker() {
  yield put(START_ACTION)
  yield take(WAIT_FOR_ACTION)
  yield delay(100)
  yield put(END_ACTION)
}

我可以runSaga像这样成功地测试它：

step('saga passes the tests', async () => {
  const channel = stdChannel()
  const dispatched = []
  const options = {
    dispatch: action => dispatched.push(action),
    getState: () => {},
    channel
  }
  const task = runSaga(options, sagaWorker)
  channel.put(WAIT_FOR_ACTION)
  await task.toPromise()
  expect(dispatched).to.deep.eql([START_ACTION, END_ACTION])
})

但是，如果我将延迟转移到汇票的前面：

function * sagaWorker() {
  yield put(START_ACTION)
  yield delay(100)
  yield take(WAIT_FOR_ACTION)
  yield put(END_ACTION)
}

现在，传奇故事没有完成并超时-到达了，take但动作从未到达频道。

是否可以使用此表格进行测试？我怀疑我可以使它通过工作call荷兰国际集团的delay真是让人不是yield直接荷兰国际集团他们，但我想知道如何让没有做这工作（如果可能的话）。

Answer 1

使用yield call(() => myPromiseyDelay(500))不会在这里保存您。派发时仍然没有什么可以注意到“丢失”的动作。

发布时WAIT_FOR_ACTION，传奇故事的状态为yield delay。这里没有要执行操作的队列，因此，到您动手时yield take(WAIT_FOR_ACTION)，该WAIT_FOR_ACTION操作早已被调度，而未被您上面显示的任何佐贺逻辑所注意到（没有活动take来抓住该操作）。

考虑设置一个actionChannel来捕获这些未监听的操作。完成后，它们将在渠道中排队等待使用delay。

因此，类似：

function * sagaWorker() {
  const channel = yield actionChannel(WAIT_FOR_ACTION)
  yield put(START_ACTION)
  yield delay(100)
  yield take(channel)
  yield put(END_ACTION)
}

因此，将所有内容组合为非伪代码：

function * sagaWorker() {
  const channel = yield actionChannel(WAIT_FOR_ACTION)
  yield put(START_ACTION)
  yield delay(100)
  yield take(channel)
  yield put(END_ACTION)
}

const {
  runSaga,
  stdChannel,
  effects: {
    take,
    put,
    actionChannel,
    delay
  }
} = window.ReduxSaga

const WAIT_FOR_ACTION = "WAIT_FOR_ACTION";
const START_ACTION = "START_ACTION";
const END_ACTION = "END_ACTION";

(async() => {
  const channel = stdChannel();
  const dispatched = [];
  const options = {
    dispatch: action => dispatched.push(action),
    getState: () => {},
    channel
  };
  const task = runSaga(options, sagaWorker);
  channel.put({
    type: WAIT_FOR_ACTION
  });
  await task.toPromise();
  console.log(dispatched);
})();

function* sagaWorker() {
  const channel = yield actionChannel(WAIT_FOR_ACTION);
  yield put({
    type: START_ACTION
  });
  yield delay(100);
  yield take(channel);
  yield put({
    type: END_ACTION
  });
}