Integrating redux-observable into existing project - Uncaught TypeError: Cannot read property 'apply' of undefined

Question

我正在尝试将 redux-observable 集成到现有的 redux 项目中，方法是绕过现有的拦截器进行一个简单的操作，并将其传递给一个新的史诗，该史诗目前应该只映射到一个新的动作类型。我收到错误：

Uncaught TypeError: Cannot read property 'apply' of undefined
    at app.js:217853
    at Array.map (<anonymous>)
    at merger (app.js:217852)
    at MapSubscriber.project (app.js:217918)
    at MapSubscriber../node_modules/rxjs/_esm5/internal/operators/map.js.MapSubscriber._next (app.js:225604)
    at MapSubscriber../node_modules/rxjs/_esm5/internal/Subscriber.js.Subscriber.next (app.js:220361)
    at Subject../node_modules/rxjs/_esm5/internal/Subject.js.Subject.next (app.js:220127)
    at Function.epicMiddleware.run (app.js:217952)
    at GenericProvider../src/bootstrap/bootstrapStore.js.exports.default [as $get] (app.js:299968)
    at Object.getService (app.js:46915)

当我加载我的项目时，它运行良好，除了我尝试重新实现的操作。

我怀疑我没有正确创建或导出我的史诗，因为当我尝试在 bootstrapStore.js:

中调用 epicMiddleware.run(registry.rootEpic) 时似乎发生了错误

const epicMiddleware = createEpicMiddleware();
[...]
export default function(registry) {
  const store = createStore([...]);
  epicMiddleware.run(registry.rootEpic);
  return store;
}

其中 registry.rootEpic 是使用 BottleJS 引导的：

bottle.factory('rootEpic', require('./bootstrapRootEpic').default);
bottle.factory('store', require('./bootstrapStore').default);

bootstrapRootEpic.js 看起来像这样：

import { combineEpics } from 'redux-observable';

import { createExercisesEpic } from 'src/actions/epics';

export default function(registry) {
  return combineEpics(createExercisesEpic);
}

createExercisesEpics定义在src/actions/epics/index.js:

export default {
  createExercisesEpic: require('./createExercisesEpic').default
};

和 createExercisesEpic.js 看起来像这样：

import { mapTo } from 'rxjs/operators';
import { ofType } from 'redux-observable';

import {
  CREATE_EXERCISES,
  CREATE_EXERCISES_COMPLETED
} from 'src/actions/types';

export default function(action$) {
  return action$.pipe(
    ofType(CREATE_EXERCISES),
    mapTo({type: CREATE_EXERCISES_COMPLETED})
  );
}

我是否遗漏了某处步骤，或者我的变量之一可能未正确定义或意外未定义？

Answer 1

问题是我试图使用这种导入样式：

import { createExercisesEpic } from 'src/actions/epics';

它仅适用于导出为函数的函数，而不适用于导出对象的命名属性。我将其更改为：

import epics from 'src/actions/epics';

export default function(registry) {
  return epics.createExercisesEpic;
}

Integrating redux-observable into existing project - Uncaught TypeError: Cannot read property 'apply' of undefined

Integrating redux-observable into existing project - Uncaught TypeError: Cannot read property 'apply' of undefined

javascript

rxjs

redux

reactivex

redux-observable