patronum/previous/index.js

☄️ Effector utility library delivering modularity and convenience

import { createStore, launch, step, is } from 'effector';
export function previous() {
  for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
    args[_key] = arguments[_key];
  }
  var [store] = args;
  var initialValue = args.length < 2 ? null : args[1];
  if (!is.store(store, {
    sid: "mzq5dc"
  })) {
    throw Error('previous first argument should be a store');
  }
  var $prevValue = createStore(initialValue, {
    and: {
      serialize: 'ignore',
      skipVoid: false
    },
    name: "$prevValue",
    sid: "e05yob"
  });
  var storeNode = store.graphite;
  storeNode.seq.push(step.compute({
    fn(upd, _, stack) {
      launch({
        target: $prevValue,
        params: stack.a,
        defer: true
      });
      return upd;
    }
  }));
  return $prevValue;
}