gistfile1.txt

REDUCER

case PostsActionTypes.LoadPostsSuccess: {
      const posts = action.payload.posts;

      const entities = posts.reduce(
        (entities: { [id: string]: Post }, post: Post) => {
          return {
            ...entities,
            [post._id]: post,
          };
        },
        {
          ...state.entities,
        }
      );

      return {
        ...state,
        loading: false,
        loaded: true,
        entities,
        ids: Object.keys(entities)
      };
      
SELECTOR

export const getPostsEntities = (state: State) => {
  const data = {};
  state.ids.forEach(id => {
    data[id] = state.entities[id];
  });
  return data;
};

PERCHE AL FILTER 

case PostsActionTypes.FilterPostsByTitle: {
      const search = action.payload.search;
      const entities = { ...state.entities};
      const ids = Object.keys(entities).filter(id => {
        return entities[id].title.indexOf(search) !== -1;
      });
      return {
        ...state,
        ids,
        error: false,
        loading: false
      };
    }