Logging createSelector.js

createSelector.js

import { createSelector, createSelectorCreator, defaultMemoize } from 'reselect'


function changeMemoize(func, changeCallback) {
  const defaultMemoizeInstance = defaultMemoize(func);
  if (changeCallback === undefined) {
    return defaultMemoizeInstance
  }

  let lastArgs = undefined;
  let lastResult = undefined;
  return (...args) => {
    const result = defaultMemoizeInstance(...args);
    if (lastResult === undefined || result !== lastResult) {
      changeCallback(lastArgs, lastResult, args, result);
      lastResult = result;
      lastArgs = args;
    }

    return result
  }
}

function createLogChange(name) {
  return  (lastArgs, lastResult, newArgs, newResult) => {
    console.log(name, lastArgs, lastResult, newArgs, newResult)
  }
}

export function createSelectorCustom(...args) {
  let name;
  if (typeof(args[0]) === 'string') {
    name = args.shift()
  }

  //return createSelector(..args)
  return createSelectorCreator(changeMemoize, createLogChange(name))(...args)
}

export default createSelectorCustom