mshahin364 · October 6, 2024 13:13 · May 18, 2019
diff --git a/deep-equals.ts b/deep-equals.ts
@@ -0,0 +1,57 @@
+const isArray = Array.isArray;
+const keyList = Object.keys;
+const hasProp = Object.prototype.hasOwnProperty;
+
+export function isDeeplyEqual<T extends any>(a: T, b: T): boolean {
+  if (a === b) { return true; }
+
+
+  if (a && b && typeof a === 'object' && typeof b === 'object') {
+    const arrA = isArray(a)
+      , arrB = isArray(b);
+    let i
+      , length
+      , key;
+
+    if (arrA && arrB) {
+      length = a.length;
+      if (length !== b.length) { return false; }
+      for (i = length; i-- !== 0;) {
+        if (!isDeeplyEqual(a[i], b[i])) { return false;
+      } }
+      return true;
+    }
+
+    if (arrA !== arrB) { return false; }
+
+    const dateA = a instanceof Date
+      , dateB = b instanceof Date;
+    if (dateA !== dateB) { return false; }
+    if (dateA && dateB) { return a.getTime() === b.getTime(); }
+
+    const regexpA = a instanceof RegExp
+      , regexpB = b instanceof RegExp;
+    if (regexpA !== regexpB) { return false; }
+    if (regexpA && regexpB) { return a.toString() === b.toString(); }
+
+    const keys = keyList(a);
+    length = keys.length;
+
+    if (length !== keyList(b).length) {
+      return false;
+    }
+
+    for (i = length; i-- !== 0;) {
+      if (!hasProp.call(b, keys[i])) { return false;
+    } }
+
+    for (i = length; i-- !== 0;) {
+      key = keys[i];
+      if (!isDeeplyEqual(a[key], b[key])) { return false; }
+    }
+
+    return true;
+  }
+
+  return a !== a && b !== b;
+}