Fixed path issues and C# version/target

Author: egil

src/AngleSharp.Diffing.Tests/Egil.AngleSharp.DiffingTests.csproj

@@ -28,7 +28,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\src\Egil.AngleSharp.Diffing.csproj" />
+    <ProjectReference Include="..\AngleSharp.Diffing\Egil.AngleSharp.Diffing.csproj" />
   </ItemGroup>
 
 </Project>

src/AngleSharp.Diffing/Core/AttributeComparison.cs

@@ -20,7 +20,7 @@ public AttributeComparison(in AttributeComparisonSource control, in AttributeCom
 
         #region Equals and HashCode
         public bool Equals(AttributeComparison other) => Control.Equals(other.Control) && Test.Equals(other.Test);
-        public override bool Equals(object obj) => obj is AttributeComparison other && Equals(other);
+        public override bool Equals(object? obj) => obj is AttributeComparison other && Equals(other);
         public override int GetHashCode() => (Control, Test).GetHashCode();
         public static bool operator ==(AttributeComparison left, AttributeComparison right) => left.Equals(right);
         public static bool operator !=(AttributeComparison left, AttributeComparison right) => !left.Equals(right);

src/AngleSharp.Diffing/Core/AttributeComparisonSource.cs

@@ -31,7 +31,7 @@ public AttributeComparisonSource(string attributeName, in ComparisonSource eleme
         #region Equals and HashCode
         public bool Equals(AttributeComparisonSource other) => Object.ReferenceEquals(Attribute, other.Attribute) && Path.Equals(other.Path, StringComparison.Ordinal) && ElementSource.Equals(other.ElementSource) ;
         public override int GetHashCode() => (Attribute, ElementSource).GetHashCode();
-        public override bool Equals(object obj) => obj is AttributeComparisonSource other && Equals(other);
+        public override bool Equals(object? obj) => obj is AttributeComparisonSource other && Equals(other);
         public static bool operator ==(AttributeComparisonSource left, AttributeComparisonSource right) => left.Equals(right);
         public static bool operator !=(AttributeComparisonSource left, AttributeComparisonSource right) => !left.Equals(right);
         #endregion

src/AngleSharp.Diffing/Core/Comparison.cs

@@ -42,7 +42,7 @@ public bool TryGetNodesAsType<TNode>([NotNullWhen(true)]out TNode? controlNode,
 
         #region Equals and HashCode
         public bool Equals(Comparison other) => Control.Equals(other.Control) && Test.Equals(other.Test);
-        public override bool Equals(object obj) => obj is Comparison other && Equals(other);
+        public override bool Equals(object? obj) => obj is Comparison other && Equals(other);
         public override int GetHashCode() => (Control, Test).GetHashCode();
         public static bool operator ==(Comparison left, Comparison right) => left.Equals(right);
         public static bool operator !=(Comparison left, Comparison right) => !left.Equals(right);

src/AngleSharp.Diffing/Core/ComparisonSource.cs

@@ -70,7 +70,7 @@ private static string CalculateNodePath(INode node, int index)
         #region Equals and HashCode
         public bool Equals(ComparisonSource other) => Object.ReferenceEquals(Node, other.Node) && Index == other.Index && Path.Equals(other.Path, StringComparison.Ordinal) && SourceType == other.SourceType;
         public override int GetHashCode() => _hashCode;
-        public override bool Equals(object obj) => obj is ComparisonSource other && Equals(other);
+        public override bool Equals(object? obj) => obj is ComparisonSource other && Equals(other);
         public static bool operator ==(ComparisonSource left, ComparisonSource right) => left.Equals(right);
         public static bool operator !=(ComparisonSource left, ComparisonSource right) => !left.Equals(right);
         #endregion

src/AngleSharp.Diffing/Egil.AngleSharp.Diffing.csproj

@@ -4,6 +4,14 @@
     <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <AnnotatedReferenceAssemblyVersion>3.0.0</AnnotatedReferenceAssemblyVersion>
+  </PropertyGroup>
+  <ItemGroup>
+	<PackageReference Include="TunnelVisionLabs.ReferenceAssemblyAnnotator" Version="1.0.0-alpha.77" PrivateAssets="all" />
+	<PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[$(AnnotatedReferenceAssemblyVersion)]" />
+  </ItemGroup>
+
   <ItemGroup>
     <Compile Remove="Matchers\**" />
     <EmbeddedResource Remove="Matchers\**" />

src/AngleSharp.Diffing/NotNullWhenAttribute.cs

@@ -4,4 +4,13 @@
     <Product>AngleSharp.Diffing</Product>
     <Version>0.13.0</Version>
   </PropertyGroup>
+  <PropertyGroup>
+    <LangVersion>8.0</LangVersion>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>CS8600;CS8602;CS8603;CS8625</WarningsAsErrors>
+  </PropertyGroup>
+  <PropertyGroup>
+    <AngleSharpVersion>0.13.0</AngleSharpVersion>
+    <FxCopAnalyzersVersion>2.9.6</FxCopAnalyzersVersion>
+  </PropertyGroup>
 </Project>