C#: Add tests for Equals methods with nullable parameter types

Author: hvitved

csharp/ql/test/query-tests/API Abuse/ClassDoesNotImplementEquals/NullableTest.cs

@@ -0,0 +1,86 @@
+using System;
+
+#nullable enable
+
+namespace Test
+{
+    class TestClass1 : IEquatable<TestClass1>
+    {
+        private int field1;
+
+        public bool Equals(TestClass1? param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object? param2)
+        {
+            return param2 is TestClass1 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+
+    class TestClass2 : IEquatable<TestClass2>
+    {
+        private int field1;
+
+        public bool Equals(TestClass2 param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object? param2)
+        {
+            return param2 is TestClass2 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+
+    class TestClass3 : IEquatable<TestClass3>
+    {
+        private int field1;
+
+        public bool Equals(TestClass3? param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object param2)
+        {
+            return param2 is TestClass3 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+
+    class TestClass4 : IEquatable<TestClass4>
+    {
+        private int field1;
+
+        public bool Equals(TestClass4 param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object param2)
+        {
+            return param2 is TestClass4 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+}

csharp/ql/test/query-tests/API Abuse/IncorrectEqualsSignature/NullableTest.cs

@@ -0,0 +1,86 @@
+using System;
+
+#nullable enable
+
+namespace Test
+{
+    class TestClass1 : IEquatable<TestClass1>
+    {
+        private int field1;
+
+        public bool Equals(TestClass1? param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object? param2)
+        {
+            return param2 is TestClass1 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+
+    class TestClass2 : IEquatable<TestClass2>
+    {
+        private int field1;
+
+        public bool Equals(TestClass2 param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object? param2)
+        {
+            return param2 is TestClass2 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+
+    class TestClass3 : IEquatable<TestClass3>
+    {
+        private int field1;
+
+        public bool Equals(TestClass3? param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object param2)
+        {
+            return param2 is TestClass3 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+
+    class TestClass4 : IEquatable<TestClass4>
+    {
+        private int field1;
+
+        public bool Equals(TestClass4 param1)
+        {
+            return param1 != null && field1 == param1.field1;
+        }
+
+        public override bool Equals(object param2)
+        {
+            return param2 is TestClass4 tc && Equals(tc);
+        }
+
+        public override int GetHashCode()
+        {
+            return field1;
+        }
+    }
+}