Enable nullability for BenchmarkDotNet.Annotations

Author: alinasmirnova

src/BenchmarkDotNet.Annotations/Attributes/ArgumentsAttribute.cs

@@ -6,13 +6,13 @@ namespace BenchmarkDotNet.Attributes
     [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
     public class ArgumentsAttribute : PriorityAttribute
     {
-        public object[] Values { get; }
+        public object?[] Values { get; }
 
         // CLS-Compliant Code requires a constructor without an array in the argument list
         [PublicAPI]
         public ArgumentsAttribute() => Values = new object[0];
 
-        public ArgumentsAttribute(params object[] values)
-            => Values = values ?? new object[] { null }; // when users do Arguments(null) they mean one, null argument
+        public ArgumentsAttribute(params object?[]? values)
+            => Values = values ?? new object?[] { null }; // when users do Arguments(null) they mean one, null argument
     }
 }

src/BenchmarkDotNet.Annotations/Attributes/BenchmarkAttribute.cs

@@ -14,7 +14,7 @@ public BenchmarkAttribute([CallerLineNumber] int sourceCodeLineNumber = 0, [Call
             SourceCodeFile = sourceCodeFile;
         }
 
-        public string Description { get; set; }
+        public string? Description { get; set; }
 
         public bool Baseline { get; set; }
 

src/BenchmarkDotNet.Annotations/Attributes/BenchmarkCategoryAttribute.cs

@@ -9,7 +9,7 @@ public class BenchmarkCategoryAttribute : Attribute
         public string[] Categories { get; }
 
         // CLS-Compliant Code requires a constructor without an array in the argument list
-        [PublicAPI] protected BenchmarkCategoryAttribute() { }
+        [PublicAPI] protected BenchmarkCategoryAttribute() => Categories = new string[0];
 
         public BenchmarkCategoryAttribute(params string[] categories) => Categories = categories;
     }

src/BenchmarkDotNet.Annotations/Attributes/ParamsAttribute.cs

@@ -5,12 +5,12 @@ namespace BenchmarkDotNet.Attributes
     [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
     public class ParamsAttribute : PriorityAttribute
     {
-        public object[] Values { get; }
+        public object?[] Values { get; }
 
         // CLS-Compliant Code requires a constructor without an array in the argument list
         public ParamsAttribute() => Values = new object[0];
 
-        public ParamsAttribute(params object[] values)
-            => Values = values ?? new object[] { null }; // when users do Params(null) they mean one, null argument
+        public ParamsAttribute(params object?[]? values)
+            => Values = values ?? new object?[] { null }; // when users do Params(null) they mean one, null argument
     }
 }

src/BenchmarkDotNet.Annotations/BenchmarkDotNet.Annotations.csproj

@@ -9,6 +9,7 @@
     <RootNamespace>BenchmarkDotNet</RootNamespace>
     <!-- needed for docfx xref resolver -->
     <ProduceReferenceAssembly>True</ProduceReferenceAssembly>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="..\BenchmarkDotNet\Helpers\CodeAnnotations.cs" Link="Attributes\CodeAnnotations.cs" />