added new diff logic (#403)

* new diff stash

* save delta

* rm redundant code

* Update index.ts

* rm old diff

* feat: separate original and repetition in encode and decode methods

* fixed libs, save stringified json

* rem payload

* returned repetition payload

* removed payload from repetition

* fixed some test, added tests for diff

* fix types

* yarn

* rm test from utils

* yarn fix

* lnt fixes

* rm log

* rm log

* improved doc

* rm redundant dep

* added jsdoc return type

---------

Co-authored-by: Peter Savchenko <specc.dev@gmail.com>

Author: slaveeks

lib/utils.js

@@ -1,4 +1,3 @@
-const _ = require('lodash');
 const https = require('https');
 
 /**
@@ -9,159 +8,6 @@ const https = require('https');
  */
 module.exports.sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms));
 
-/**
- * Make `deepDiff` exportable
- * return {object}
- */
-module.exports.deepDiff = deepDiff;
-
-/**
- * Make `deepMerge` exportable
- * return {object}
- */
-module.exports.deepMerge = deepMerge;
-
-/**
- * Recursively scans two variables and returns another object with diffs
- *
- * @param {object|Array} source - source object
- * @param {object|Array} target - target object
- * @returns {object}
- */
-function deepDiff(source, target) {
-  const sourceType = typeOf(source);
-  const targetType = typeOf(target);
-
-  /**
-   * If we'll compare NOTHING with SOMETHING, the diff will be SOMETHING
-   */
-  if (source === undefined) {
-    return target;
-  }
-
-  /**
-   * If we'll compare SOMETHING with NOTHING, the diff will be NOTHING
-   */
-  if (targetType === undefined) {
-    return undefined;
-  }
-
-  /**
-   * We CAN'T compare apples with dogs
-   */
-  if (sourceType !== targetType) {
-    return undefined;
-  }
-
-  if (targetType === 'array') {
-    return arrayDiff(source, target);
-  } else if (targetType === 'object') {
-    return objectDiff(source, target);
-  } else if (source !== target) {
-    return target;
-  } else {
-    return source;
-  }
-}
-
-/**
- * Returns two arrays difference as an new array
- *
- * @param {Array} source - source object
- * @param {Array} target - target object
- * @returns {Array}
- */
-function arrayDiff(source, target) {
-  const diffArray = [];
-
-  for (let i = 0; i < target.length; i++) {
-    diffArray[i] = deepDiff(source[i], target[i]);
-  }
-
-  return diffArray;
-}
-
-/**
- * Returns two objects difference as new object
- *
- * @param {object} objectA - first object for comparing
- * @param {object} objectB - second object for comparing
- *
- * @returns {object}
- */
-function objectDiff(objectA, objectB) {
-  const diffObject = {};
-
-  /**
-   * objectA is a subject,
-   * we compare objectB patches
-   *
-   * For that we enumerate objectB props and assume that
-   * target object has any changes
-   *
-   * But target object might have additional patches that might not be in subject
-   * This corner case says us that whole property is a patch
-   */
-  if (!objectA) {
-    return objectB;
-  }
-
-  Object.keys(objectB).forEach((prop) => {
-    const objectAItem = objectA[prop];
-    const objectBItem = objectB[prop];
-
-    if (objectAItem === undefined) {
-      diffObject[prop] = objectBItem;
-
-      return;
-    }
-
-    if (objectAItem === objectBItem) {
-      return;
-    }
-
-    diffObject[prop] = deepDiff(objectAItem, objectBItem);
-  });
-
-  return diffObject;
-}
-
-/**
- * Merge to objects recursively
- *
- * @param {object} target - target object
- * @param {object[]} sources - sources for mering
- * @returns {object}
- */
-function deepMerge(target, ...sources) {
-  const isObject = (item) => item && typeOf(item) === 'object';
-
-  return _.mergeWith({}, target, ...sources, function (_subject, _target) {
-    if (_.isArray(_subject) && _.isArray(_target)) {
-      const biggerArray = _subject.length > _target.length ? _subject : _target;
-      const lesser = _subject.length > _target.length ? _target : _subject;
-
-      return biggerArray.map((el, i) => {
-        if (isObject(el) && isObject(lesser[i])) {
-          return _.mergeWith({}, el, lesser[i]);
-        } else {
-          return el;
-        }
-      });
-    }
-  });
-}
-
-/**
- * Returns real type of passed variable
- *
- * @param {*} obj - value to check
- * @returns {string}
- */
-function typeOf(obj) {
-  return Object.prototype.toString.call(obj).match(/\s([a-zA-Z]+)/)[1].toLowerCase();
-}
-
 /**
  * Sends alert to the Slack/Telegram
  *