raid-addons/lib/sin.js

Add-ons functions for use with Raid

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;

function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); if (enumerableOnly) symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; }); keys.push.apply(keys, symbols); } return keys; }

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; if (i % 2) { ownKeys(Object(source), true).forEach(function (key) { _defineProperty(target, key, source[key]); }); } else if (Object.getOwnPropertyDescriptors) { Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)); } else { ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } } return target; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

function fold(updates, state, event) {
  return Promise.all(updates.map(function (update) {
    return update(state, event);
  }));
}

function sin() {
  var key = Math.random().toString(16).slice(4);
  var updates = Array.from(arguments).slice(1, arguments.length);
  var signal = arguments[0];

  if (!signal || !signal.emit) {
    throw new Error('[Sin] requires an emitter source');
  }

  return function (state, event) {
    if (event.type === key) {
      return event.payload;
    }

    Promise.resolve(fold(updates, state, event)).then(function (res) {
      var collected = res.reduce(function (newState) {
        return _objectSpread({
          state: state
        }, newState);
      }, state);
      signal.emit({
        type: key,
        payload: collected
      });
    });
    return state;
  };
}

var _default = sin;
exports["default"] = _default;