Fix IsEqualTo assertion for double.NaN values

TUnit.Assertions.Tests/Old/DoubleEqualsToAssertionTests.cs

@@ -20,6 +20,24 @@ public async Task Double_EqualsTo_Failure()
         await TUnitAssert.ThrowsAsync<TUnitAssertionException>(async () => await TUnitAssert.That(double1).IsEqualTo(double2));
     }
 
+    [Test]
+    public async Task Double_NaN_EqualsTo_NaN_Success()
+    {
+        await TUnitAssert.That(double.NaN).IsEqualTo(double.NaN);
+    }
+
+    [Test]
+    public async Task Double_PositiveInfinity_EqualsTo_PositiveInfinity_Success()
+    {
+        await TUnitAssert.That(double.PositiveInfinity).IsEqualTo(double.PositiveInfinity);
+    }
+
+    [Test]
+    public async Task Double_NegativeInfinity_EqualsTo_NegativeInfinity_Success()
+    {
+        await TUnitAssert.That(double.NegativeInfinity).IsEqualTo(double.NegativeInfinity);
+    }
+
 #if NET
     [Test]
     public async Task Double_EqualsTo__With_Tolerance_Success()

TUnit.Assertions/Conditions/SpecializedEqualityAssertions.cs

@@ -167,7 +167,7 @@ protected override Task<AssertionResult> CheckAsync(EvaluationMetadata<double> m
             return Task.FromResult(AssertionResult.Failed($"found {value}, which differs by {diff}"));
         }
 
-        if (value == _expected)
+        if (double.Equals(value, _expected))
         {
             return Task.FromResult(AssertionResult.Passed);
         }