refactor: fix flow & eslint errors

Author: Valeriy Borodayev

src/definitions.js

@@ -1,5 +1,5 @@
 // @flow
-/* eslint-disable no-await-in-loop */
+/* eslint-disable no-await-in-loop, max-classes-per-file, import/no-cycle */
 
 import type { ObjectId, MongooseModel, MongooseDocument } from 'mongoose';
 import MHD, { revertChanges } from './diff';

src/diff.js

@@ -58,14 +58,14 @@ export const deepDiff = (
     (stack &&
       stack.length > 0 &&
       stack[stack.length - 1].lhs &&
-      Object.getOwnPropertyDescriptor(stack[stack.length - 1].lhs, key));
+      !!Object.getOwnPropertyDescriptor((stack[stack.length - 1].lhs: any), key));
 
   const rdefined =
     !!rhs ||
     (stack &&
       stack.length > 0 &&
       stack[stack.length - 1].rhs &&
-      Object.getOwnPropertyDescriptor(stack[stack.length - 1].rhs, key));
+      !!Object.getOwnPropertyDescriptor((stack[stack.length - 1].rhs: any), key));
 
   if (!ldefined && rdefined) {
     changes.push({ k: 'N', p: currentPath, r: rhs });

src/utils.js

@@ -171,7 +171,7 @@ export const revertArrayChange = (arr: Array<any>, index: number, change: any):
 export const deepClone = (obj: any): any => {
   if (realTypeOf(obj) === 'object') {
     const clone = { ...obj };
-    // eslint-disable-next-line no-restricted-syntax
+    // eslint-disable-next-line no-restricted-syntax, no-unused-vars
     for (const k in clone) {
       if (clone.hasOwnProperty(k)) {
         clone[k] = deepClone(clone[k]);