Before testing

before-testing.js

import * as effects from "redux-saga/effects";
import { END, eventChannel } from "redux-saga";
import * as constants from "../actions/constants";
import io from "socket.io-client";

export function* processTaskTimeConsuming() {
  yield effects.delay(3000 + 1000 * Math.random());
}

function* doProcessTask(name) {
  try {
    yield effects.put({ type: constants.TASK_PROCESS_START, name });
    yield effects.call(processTaskTimeConsuming);
    yield effects.put({ type: constants.TASK_PROCESS_DONE, name });
  } catch (error) {
    yield effects.put({ type: constants.TASK_PROCESS_ERROR, name });
  } finally {
    if (yield effects.cancelled()) {
      yield effects.put({ type: constants.TASK_PROCESS_RESET, name });
    }
    return true;
  }
}

export function* processTask(action) {
  yield effects.call(doProcessTask, action.name);
}

function* wsEmitter() {
  //const io = yield effects.getContext("io");
  const socket = yield effects.call(io, "http://localhost:3001");
  return eventChannel(emitter => {
    socket.on("disconnect", reason => {
      emitter(END);
      socket.close();
    });
    socket.on("message", event => emitter(event));
    // The subscriber must return an unsubscribe function
    return () => {
      socket.close();
    };
  });
}

export function* wsHandler() {
  const wsChan = yield effects.call(wsEmitter);
  while (true) {
    const event = yield effects.take(wsChan);
    if (event.type === "create") {
      yield effects.put({ type: constants.TASK_CREATE, name: event.name });
    }
  }
}

export function* rootSaga() {
  yield effects.takeEvery(constants.TASK_PROCESS, processTask);
  yield effects.fork(wsHandler);
}