From 4a86b3ed8e1a91294e6f067329ab6a7c981ec336 Mon Sep 17 00:00:00 2001
From: Igor Kamyshev <igor@kamyshev.me>
Date: Mon, 30 Oct 2023 16:28:30 +0700
Subject: [PATCH] Fix undefined case in isEqual with custom classes with no
 valueOf

---
 .changeset/eighty-laws-accept.md              |  5 ++++
 .../libs/lohyphen/__tests__/is_equal.test.ts  | 24 +++++++++++++------
 packages/core/src/libs/lohyphen/is_equal.ts   | 16 +------------
 3 files changed, 23 insertions(+), 22 deletions(-)
 create mode 100644 .changeset/eighty-laws-accept.md

diff --git a/.changeset/eighty-laws-accept.md b/.changeset/eighty-laws-accept.md
new file mode 100644
index 000000000..63e087bd9
--- /dev/null
+++ b/.changeset/eighty-laws-accept.md
@@ -0,0 +1,5 @@
+---
+'@farfetched/core': patch
+---
+
+Fix undefined case in isEqual with custom classes with no valueOf
diff --git a/packages/core/src/libs/lohyphen/__tests__/is_equal.test.ts b/packages/core/src/libs/lohyphen/__tests__/is_equal.test.ts
index 2d31ab1b0..5ed74a622 100644
--- a/packages/core/src/libs/lohyphen/__tests__/is_equal.test.ts
+++ b/packages/core/src/libs/lohyphen/__tests__/is_equal.test.ts
@@ -114,19 +114,29 @@ describe('isEqual', () => {
   });
 
   describe('Custom objects', () => {
-    class MyValueObject {
-      constructor(private value: number) {}
-      valueOf() {
-        return this.value;
+    test('custom object with custom valueOf', () => {
+      class MyValueObject {
+        constructor(private value: number) {}
+        valueOf() {
+          return this.value;
+        }
       }
-    }
 
-    test('same', () => {
       expect(isEqual(new MyValueObject(1), new MyValueObject(1))).toBe(true);
+      expect(isEqual(new MyValueObject(1), new MyValueObject(2))).toBe(false);
     });
 
-    test('different', () => {
+    test('custom object with no custom valueOf', () => {
+      class MyValueObject {
+        constructor(public value: number) {}
+      }
+
       expect(isEqual(new MyValueObject(1), new MyValueObject(2))).toBe(false);
+      /*
+       * Consider same obejects as different,
+       * because we have no idea how to compare them without custom valueOf
+       */
+      expect(isEqual(new MyValueObject(1), new MyValueObject(1))).toBe(false);
     });
   });
 
diff --git a/packages/core/src/libs/lohyphen/is_equal.ts b/packages/core/src/libs/lohyphen/is_equal.ts
index d874a1a10..5b7905c94 100644
--- a/packages/core/src/libs/lohyphen/is_equal.ts
+++ b/packages/core/src/libs/lohyphen/is_equal.ts
@@ -71,23 +71,9 @@ export function isEqual(a: any, b: any): boolean {
 
       return true;
     } else if (typeA === 'object') {
-      if (
-        a.valueOf &&
-        b.valueOf &&
-        a.valueOf !== Object.prototype.valueOf() &&
-        b.valueOf !== Object.prototype.valueOf()
-      ) {
+      if (a.valueOf && b.valueOf) {
         return a.valueOf() === b.valueOf();
       }
-
-      if (
-        a.toString &&
-        a.toString &&
-        a.toString !== Object.prototype.toString() &&
-        b.toString !== Object.prototype.toString()
-      ) {
-        return a.toString() === b.toString();
-      }
     }
   } catch (e) {
     // We got extremely weird objects, let us skip it and consider them not equal