From 29f9547e5355adaa887172d43f35a7a10f202579 Mon Sep 17 00:00:00 2001
From: Carl-Erik Kopseng <carlerik@gmail.com>
Date: Thu, 17 Oct 2024 20:30:46 +0200
Subject: [PATCH] Ensure checks based on the constructor property passes for
 fake Dates (#511)

---
 src/fake-timers-src.js   | 4 ++++
 test/fake-timers-test.js | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/src/fake-timers-src.js b/src/fake-timers-src.js
index 308daf1..f368628 100644
--- a/src/fake-timers-src.js
+++ b/src/fake-timers-src.js
@@ -447,6 +447,10 @@ function withGlobal(_global) {
                 } else {
                     super(...arguments);
                 }
+
+                // ensures identity checks using the constructor prop still works
+                // this should have no other functional effect
+                this.constructor = Date;
             }
 
             static [Symbol.hasInstance](instance) {
diff --git a/test/fake-timers-test.js b/test/fake-timers-test.js
index 7a67b9e..38e08e0 100644
--- a/test/fake-timers-test.js
+++ b/test/fake-timers-test.js
@@ -3200,6 +3200,15 @@ describe("FakeTimers", function () {
             assert(date instanceof realDate.constructor);
         });
 
+        // issue #510
+        it("creates Date objects where the constructor prop matches the original", function () {
+            const realDate = new Date();
+            const date = new this.clock.Date();
+
+            assert.equals(date.constructor.name, realDate.constructor.name);
+            assert.equals(date.constructor, realDate.constructor);
+        });
+
         it("creates Date objects representing clock time", function () {
             const date = new this.clock.Date();