redux-shelf/src/communication.js

Helper reducers and actions to take away your boilerplate code from both Data and Communication state types

function generateActionByStatus(status) {
  return (type, selector) => {
    const action = {
      type: `communication/${type}/${status}`,
      meta: { type, status },
    };

    if (selector) {
      action.meta.selector = selector;
    }

    return action;
  };
}

export const cancel = generateActionByStatus('CANCEL');

export const done = generateActionByStatus('DONE');

export function fail(type, ...args) {
  let selector;
  let error;

  if (args.length > 1) {
    [selector, error] = args;
  } else {
    [error] = args;
  }

  const action = generateActionByStatus('FAIL')(type, selector);

  if (error) {
    action.payload = error;
    action.error = true;
  }

  return action;
}

export const starting = generateActionByStatus('STARTING');

function of(type, selector) {
  const identifier = [type];
  if (selector) {
    identifier.push(selector);
  }

  const state = this[identifier.join(':')] || {};

  return {
    loading: state.status === 'STARTING',
    error: state.error,
  };
}

function reducer(state = {}, action) {
  if (
    !action.type ||
    !action.type.startsWith('communication') ||
    !(action.meta && action.meta.status)
  ) {
    return state;
  }

  const identifier = [action.meta.type];
  if (action.meta.selector) {
    identifier.push(action.meta.selector);
  }

  switch (action.meta.status) {
    case 'STARTING':
      return {
        ...state,
        [identifier.join(':')]: {
          status: action.meta.status,
        },
      };

    case 'DONE':
    case 'CANCEL': {
      const { [identifier.join(':')]: omit, ...newState } = state;
      return newState;
    }

    case 'FAIL':
      return {
        ...state,
        [identifier.join(':')]: {
          status: action.meta.status,
          error: action.payload,
        },
      };

    default:
      return state;
  }
}

export default function communication(state, action) {
  const newState = reducer(state, action);
  newState.of = of;

  return newState;
}

communication.cancel = cancel;
communication.done = done;
communication.fail = fail;
communication.starting = starting;