title: State is empty in reducer
body: <p>I working on a <code>react-redux webapp</code> and until now, all action were related to <code>ajax</code> requests, so I'm using <code>redux thunk and axios</code>.
  Now, I'm working in a component that would create a list from objects called 'tasks'. This should be very straight forward: the action calls send the task object and the reducer add it in an array inside the 'tasks' state.</p>
  
  <p>The issue is that when called the reducer always rewrite the the tasks object array. Doing a console.log at the beginning of the reducer call I see the state is always empty.</p>
  
  <p>Here is the code: </p>
  
  <pre><code>import {DROP_TASK} from '../actions/types'
  
  export default function (state = {}, action) {
      switch (action.type){
          case(DROP_TASK):
  
              console.log("state", state); // here is shows object{}
  
              console.log('tasks', state.tasks);
  
              if(state.tasks === undefined || state.tasks === null ) {
  
                  return {...state, list: [action.payload]}
              }
  
  
  
              return {...state, list: [...state.tasks.list, action.payload]};
          default:
              return state
      }
  }
  </code></pre>
  
  <p>at the createStore at the index.js </p>
  
  <p>I'm doing:</p>
  
  <pre><code>const createStoreWithMiddleware = applyMiddleware(reduxThunk, logger)(createStore);
  </code></pre>
  
  <p>where logger just console.log the whole state before and after every dispatch. So I know that before the dispatch for the reducer function, the "tasks" is populated after a first call.</p>
  
  <p>Here is how I'm combining reducers:</p>
  
  <pre><code>import { combineReducers } from 'redux';
  import {reducer as form} from 'redux-form';
  import {reducer as uiReducer} from 'redux-ui';
  import authReducer from './auth_reducer';
  import treeReducer from './tree_reducer';
  import media_asset_list_reducers from './media_asset_list_reducers';
  import tasks from './tasks';
  
  const reducers = combineReducers({
      form: form,
      auth: authReducer,
      tree: treeReducer,
      media_asset_list: media_asset_list_reducers,
      tasks: tasks,
      ui: uiReducer
  });
  
  
  export default reducers;
  </code></pre>
  
  <p>Can anyone help me?</p>
  
  <p>Thanks</p>