jmeas/redux-resource

import setResourceMeta from '../utils/set-resource-meta';
import initialResourceMetaState from './initial-resource-meta-state';
import warning from './warning';

// This helper is used to simplify non-success reducers. Because non-success
// reducers don't modify the data – ever – it simplifies the scope of what can
// change.
// Basically, two things can change:
//
// 1. Request status for resource IDs in `meta`, if IDs are passed in
// 2. Request status for a named request
//
// A named request's IDs don't change, and neither does the resource. Consequently,
// this helper completely defines all of the ways in which the non-success reducers
// can change the state.
export default function(crudAction, requestStatus) {
  return function(state, action, { initialResourceMeta } = {}) {
    const resources = action.resources;
    const mergeMeta = action.mergeMeta;

    let requestKey, requestName;
    if (action.request && typeof action.request === 'string') {
      requestKey = requestName = action.request;
    }
    if (action.requestKey && typeof action.requestKey === 'string') {
      requestKey = action.requestKey;
    }
    if (action.requestName && typeof action.requestName === 'string') {
      requestName = action.requestName;
    }

    let idList;
    if (resources) {
      idList = resources.map(r => {
        if (typeof r === 'object') {
          return r.id;
        } else {
          return r;
        }
      });
    } else {
      idList = [];
    }

    const statusAttribute = `${crudAction}Status`;
    let newRequests, newMeta, newLists;

    if (!requestKey && !idList.length) {
      if (process.env.NODE_ENV !== 'production') {
        warning(
          `A Redux Resource action of type ${action.type} was dispatched ` +
            `without a "requestKey" or "resources" array. Without one of these ` +
            `values, Redux Resource cannot track the request status for this ` +
            `CRUD operation. You should check your Action Creators. Read more about ` +
            `request tracking at: https://redux-resource.js.org/docs/other-guides/tracking-request-statuses.html`,
          'NO_OP_NON_SUCCESS_ACTION'
        );
      }

      return state;
    }

    if (requestKey) {
      const existingRequest = state.requests[requestKey] || {};

      const newRequest = {
        ...existingRequest,
        ...action.requestProperties,
        requestKey,
        resourceType: action.resourceType || action.resourceName,
        status: requestStatus,
      };

      if (requestName) {
        newRequest.requestName = requestName;
      }

      newRequests = {
        ...state.requests,
        [requestKey]: newRequest,
      };
    } else {
      newRequests = state.requests;
    }

    // Lists only change when a request succeeds
    newLists = { ...state.lists };

    if (idList.length) {
      newMeta = setResourceMeta({
        meta: state.meta,
        newMeta: { [statusAttribute]: requestStatus },
        resources: idList,
        mergeMeta,
        initialResourceMeta: {
          ...initialResourceMetaState,
          ...initialResourceMeta,
        },
      });
    } else {
      newMeta = state.meta;
    }

    return {
      ...state,
      requests: newRequests,
      lists: newLists,
      meta: newMeta,
    };
  };
}