login-saga.js

import {
  call,
  put,
  race,
  select,
  take,
  takeLatest
} from 'redux-saga/effects';

import actionGenerators from '../../../creators/actionGenerators';
import api from './api';

const {
  start, cancel, succeed, fail
} = actionGenerators.auth.login;

function* login() {
  try {
    let data = yield call(api);
    yield put(succeed(data));
  } catch (e) {
    return yield put(fail(e));
  }
}

const loginSaga = function* () {
  yield takeLatest([start], function* (...args) {
    yield race({
      task: call(login, ...args),
      cancel: take(cancel)
    });
  });
};

export default loginSaga;