Redux-Saga - 观察者，takeEvery

我学习react-saga了，按照这个来源的例子做了一切：https ://hackernoon.com/redux-saga-tutorial-for-beginners-and-dog-lovers-aa69a17db645

以前，我react-thunk在一个单独的文件actionTypes.js（然后我注意到，如果您在 中takeEvery替换一个变量API_CALL_REQUEST，则没有任何效果，但如果您替换"API_CALL_REQUEST"它，它会起作用。这是为什么？

动作/actionTypes.js

export const API_CALL_SUCCESS = "API_CALL_SUCCESS";
export const API_CALL_FAILURE = "API_CALL_FAILURE";
export const API_CALL_REQUEST = "API_CALL_REQIEST";

传奇/index.js

import { call, put, takeEvery } from 'redux-saga/effects';
import axios from 'axios';
import { 
    API_CALL_REQUEST, 
    API_CALL_SUCCESS, 
    API_CALL_FAILURE 
} from '../actions/actionTypes';

export function* watcherSaga() {
    yield takeEvery("API_CALL_REQUEST", workerSaga);
}

function fetchDog() {
    return axios({
        method: "GET",
        url: "https://dog.ceo/api/breeds/image/random"
    });
}

function* workerSaga() {
    try {
        const response = yield call(fetchDog);
        const dog = response.data.message;
        yield put({ type: API_CALL_SUCCESS, data: dog });
    } catch (error) {
        yield put({ type: API_CALL_FAILURE, data: error });
    }
}

如果是这样：

export function* watcherSaga() {
    const test = "API_CALL_REQUEST";
    yield takeEvery(test, workerSaga);
}

那么它可以工作，但如果是这样：

export function* watcherSaga() {
    const test = API_CALL_REQUEST;
    yield takeEvery(test, workerSaga);
}

再次没有。常数有什么问题API_CALL_REQUEST？同一文件中的其他常量没有问题。