From 0bc0c59a14f06a4d33b5f9914d0947e03384b440 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 16 Feb 2026 10:35:29 +0000
Subject: [PATCH] Add test cases for nullable Equals methods

Adds test cases for Equals methods with nullable reference type parameters
(object?) to verify the fix works correctly.

Co-authored-by: hvitved <3667920+hvitved@users.noreply.github.com>
---
 .../frameworks/system/Equals/Equals.cs              | 13 +++++++++++++
 .../frameworks/system/Equals/Equals.expected        |  2 ++
 2 files changed, 15 insertions(+)

diff --git a/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.cs b/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.cs
index 504c8119835..02b9e6b340a 100644
--- a/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.cs
+++ b/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.cs
@@ -24,3 +24,16 @@ struct Equals1Struct
 {
     public override bool Equals(object other) => false;
 }
+
+#nullable enable
+
+class NullableEquals1
+{
+    public override bool Equals(object? other) => false;
+}
+
+class NullableEquals2 : IEquatable<NullableEquals2>
+{
+    public bool Equals(NullableEquals2? other) => other != null;
+    public override bool Equals(object? other) => other is NullableEquals2 n && Equals(n);
+}
diff --git a/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.expected b/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.expected
index b05c8852b2b..30dafbad341 100644
--- a/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.expected
+++ b/csharp/ql/test/library-tests/frameworks/system/Equals/Equals.expected
@@ -5,3 +5,5 @@
 | Equals.cs:16:7:16:13 | Equals3 | Equals3.Equals(Equals3) | true |
 | Equals.cs:21:8:21:21 | NoEqualsStruct | System.ValueType.Equals(object) | false |
 | Equals.cs:23:8:23:20 | Equals1Struct | Equals1Struct.Equals(object) | true |
+| Equals.cs:31:7:31:21 | NullableEquals1 | NullableEquals1.Equals(object) | true |
+| Equals.cs:36:7:36:21 | NullableEquals2 | NullableEquals2.Equals(NullableEquals2) | true |