Replace deprecated lodash.isequal with internal implementation to remove warnings

package.json

@@ -7,13 +7,11 @@
   "main": "dist/Delta.js",
   "dependencies": {
     "fast-diff": "^1.3.0",
-    "lodash.clonedeep": "^4.5.0",
-    "lodash.isequal": "^4.5.0"
+    "lodash.clonedeep": "^4.5.0"
   },
   "devDependencies": {
     "@types/jasmine": "^3.10.3",
     "@types/lodash.clonedeep": "^4.5.6",
-    "@types/lodash.isequal": "^4.5.5",
     "@types/node": "^17.0.21",
     "@typescript-eslint/eslint-plugin": "^5.14.0",
     "@typescript-eslint/parser": "^5.14.0",

src/AttributeMap.ts

@@ -1,5 +1,5 @@
 import cloneDeep = require('lodash.clonedeep');
-import isEqual = require('lodash.isequal');
+import { isEqual } from './utils/isEqual';
 
 interface AttributeMap {
   [key: string]: unknown;

src/Delta.ts

@@ -1,9 +1,9 @@
 import * as diff from 'fast-diff';
 import cloneDeep = require('lodash.clonedeep');
-import isEqual = require('lodash.isequal');
 import AttributeMap from './AttributeMap';
 import Op from './Op';
 import OpIterator from './OpIterator';
+import { isEqual } from './utils/isEqual';
 
 const NULL_CHARACTER = String.fromCharCode(0); // Placeholder char for embed in diff()
 

src/utils/isEqual.ts

@@ -0,0 +1,33 @@
+export const isEqual = (a: any, b: any): boolean => {
+    if (a === b) return true;
+
+    if (a == null || b == null || typeof a !== 'object' || typeof b !== 'object') {
+      return false;
+    }
+
+    if (Array.isArray(a)) {
+      if (!Array.isArray(b)) return false;
+      if (a.length !== b.length) return false;
+
+      for (let i = 0; i < a.length; i++) {
+        if (!isEqual(a[i], b[i])) return false;
+      }
+
+      return true;
+    }
+
+    if (Array.isArray(b)) return false;
+
+    const aKeys = Object.keys(a);
+    const bKeys = Object.keys(b);
+
+    if (aKeys.length !== bKeys.length) return false;
+
+    for (const key of aKeys) {
+      if (!Object.prototype.hasOwnProperty.call(b, key)) return false;
+      if (!isEqual(a[key], b[key])) return false;
+    }
+
+    return true;
+  }
+