instrumental/app/javascript/mastodon/reducers/statuses.js

import {
  REBLOG_REQUEST,
  REBLOG_FAIL,
  FAVOURITE_REQUEST,
  FAVOURITE_FAIL,
  UNFAVOURITE_SUCCESS,
  BOOKMARK_REQUEST,
  BOOKMARK_FAIL,
} from '../actions/interactions';
import {
  STATUS_MUTE_SUCCESS,
  STATUS_UNMUTE_SUCCESS,
  STATUS_REVEAL,
  STATUS_HIDE,
} from '../actions/statuses';
import { TIMELINE_DELETE } from '../actions/timelines';
import { STATUS_IMPORT, STATUSES_IMPORT } from '../actions/importer';
import { Map as ImmutableMap, fromJS } from 'immutable';

const importStatus = (state, status) => state.set(status.id, fromJS(status));

const importStatuses = (state, statuses) =>
  state.withMutations(mutable => statuses.forEach(status => importStatus(mutable, status)));

const deleteStatus = (state, id, references) => {
  references.forEach(ref => {
    state = deleteStatus(state, ref[0], []);
  });

  return state.delete(id);
};

const initialState = ImmutableMap();

export default function statuses(state = initialState, action) {
  switch(action.type) {
  case STATUS_IMPORT:
    return importStatus(state, action.status);
  case STATUSES_IMPORT:
    return importStatuses(state, action.statuses);
  case FAVOURITE_REQUEST:
    return state.setIn([action.status.get('id'), 'favourited'], true);
  case UNFAVOURITE_SUCCESS:
    const favouritesCount = action.status.get('favourites_count');
    return state.setIn([action.status.get('id'), 'favourites_count'], favouritesCount - 1);
  case FAVOURITE_FAIL:
    return state.get(action.status.get('id')) === undefined ? state : state.setIn([action.status.get('id'), 'favourited'], false);
  case BOOKMARK_REQUEST:
    return state.get(action.status.get('id')) === undefined ? state : state.setIn([action.status.get('id'), 'bookmarked'], true);
  case BOOKMARK_FAIL:
    return state.get(action.status.get('id')) === undefined ? state : state.setIn([action.status.get('id'), 'bookmarked'], false);
  case REBLOG_REQUEST:
    return state.setIn([action.status.get('id'), 'reblogged'], true);
  case REBLOG_FAIL:
    return state.get(action.status.get('id')) === undefined ? state : state.setIn([action.status.get('id'), 'reblogged'], false);
  case STATUS_MUTE_SUCCESS:
    return state.setIn([action.id, 'muted'], true);
  case STATUS_UNMUTE_SUCCESS:
    return state.setIn([action.id, 'muted'], false);
  case STATUS_REVEAL:
    return state.withMutations(map => {
      action.ids.forEach(id => {
        if (!(state.get(id) === undefined)) {
          map.setIn([id, 'hidden'], false);
        }
      });
    });
  case STATUS_HIDE:
    return state.withMutations(map => {
      action.ids.forEach(id => {
        if (!(state.get(id) === undefined)) {
          map.setIn([id, 'hidden'], true);
        }
      });
    });
  case TIMELINE_DELETE:
    return deleteStatus(state, action.id, action.references);
  default:
    return state;
  }
};