Merge pull request #47 from diegofrata/null-reference

Fixes null reference exception coming from System.HashCode in .NET 4.7
diegofrata · Jan 5, 2023 · 5a73651 · 5a73651
2 parents c5e8fd8 + 9cd3c9c
commit 5a73651
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Showing 6 changed files with 40 additions and 9 deletions.
diff --git a/Generator.Equals.Runtime/DefaultEqualityComparer.cs b/Generator.Equals.Runtime/DefaultEqualityComparer.cs
@@ -24,7 +24,7 @@ class ObjectEqualityComparer : IEqualityComparer<T>
         {
             public bool Equals(T x, T y) => object.Equals(x, y);
 
-            public int GetHashCode(T obj) => obj!.GetHashCode();
+            public int GetHashCode(T obj) => obj?.GetHashCode() ?? 0;
         }
     }
 }
diff --git a/Generator.Equals.Tests/Runtime/DefaultEqualityComparerTests.cs b/Generator.Equals.Tests/Runtime/DefaultEqualityComparerTests.cs
@@ -0,0 +1,31 @@
+using FluentAssertions;
+using Xunit;
+
+namespace Generator.Equals.Tests.Runtime;
+
+public partial class DefaultEqualityComparerTests
+{
+    [Equatable]
+    sealed partial class SealedClass
+    {
+    }
+
+    [Equatable]
+    partial class NonSealedClass
+    {
+    }
+
+
+    [Fact]
+    public void GetHashCode_SealedClass_NullValueShouldReturnZero()
+    {
+        DefaultEqualityComparer<SealedClass>.Default.GetHashCode(null).Should().Be(0);
+    }
+
+
+    [Fact]
+    public void GetHashCode_NonSealedClass_NullValueShouldReturnZero()
+    {
+        DefaultEqualityComparer<NonSealedClass>.Default.GetHashCode(null).Should().Be(0);
+    }
+}
diff --git a/...sts/Runtime/DictionaryEqualityComparer.cs → ...untime/DictionaryEqualityComparerTests.cs b/...sts/Runtime/DictionaryEqualityComparer.cs → ...untime/DictionaryEqualityComparerTests.cs
@@ -4,11 +4,11 @@
 
 namespace Generator.Equals.Tests.Runtime;
 
-public class DictionaryEqualityComparer
+public class DictionaryEqualityComparerTests
 {
     readonly DictionaryEqualityComparer<string, int> _sut;
 
-    public DictionaryEqualityComparer()
+    public DictionaryEqualityComparerTests()
     {
         _sut = new DictionaryEqualityComparer<string, int>(
             new ReverseEqualityComparer(),

diff --git a/....Tests/Runtime/OrderedEqualityComparer.cs → ...s/Runtime/OrderedEqualityComparerTests.cs b/....Tests/Runtime/OrderedEqualityComparer.cs → ...s/Runtime/OrderedEqualityComparerTests.cs
@@ -4,13 +4,13 @@
 
 namespace Generator.Equals.Tests.Runtime;
 
-public class OrderedEqualityComparer
+public class OrderedEqualityComparerTests
 {
     readonly OrderedEqualityComparer<int> _sut;
     readonly int[] _a;
     readonly int[] _b;
 
-    public OrderedEqualityComparer()
+    public OrderedEqualityComparerTests()
     {
         _sut = new OrderedEqualityComparer<int>(
             new NegativeEqualityComparer()

diff --git a/...uals.Tests/Runtime/SetEqualityComparer.cs → ...Tests/Runtime/SetEqualityComparerTests.cs b/...uals.Tests/Runtime/SetEqualityComparer.cs → ...Tests/Runtime/SetEqualityComparerTests.cs
@@ -4,11 +4,11 @@
 
 namespace Generator.Equals.Tests.Runtime;
 
-public class SetEqualityComparer
+public class SetEqualityComparerTests
 {
     readonly SetEqualityComparer<int> _sut;
 
-    public SetEqualityComparer()
+    public SetEqualityComparerTests()
     {
         _sut = new SetEqualityComparer<int>(
             new NegativeEqualityComparer()

diff --git a/...ests/Runtime/UnorderedEqualityComparer.cs → ...Runtime/UnorderedEqualityComparerTests.cs b/...ests/Runtime/UnorderedEqualityComparer.cs → ...Runtime/UnorderedEqualityComparerTests.cs
@@ -4,13 +4,13 @@
 
 namespace Generator.Equals.Tests.Runtime;
 
-public class UnorderedEqualityComparer
+public class UnorderedEqualityComparerTests
 {
     readonly UnorderedEqualityComparer<int> _sut;
     readonly int[] _a;
     readonly int[] _b;
 
-    public UnorderedEqualityComparer()
+    public UnorderedEqualityComparerTests()
     {
         _sut = new UnorderedEqualityComparer<int>(
             new NegativeEqualityComparer()