chore: Add nullable annotations to projects (#3011)

* chore: add nullable annotations

* chore: apply code formatter to fix mixed CRLF/LF

Author: filzrev

samples/BenchmarkDotNet.Samples.FSharp/BenchmarkDotNet.Samples.FSharp.fsproj

@@ -6,6 +6,7 @@
     <GenerateProgramFile>false</GenerateProgramFile>
     <!-- Disable parallel tests between TargetFrameworks -->
     <TestTfmsInParallel>false</TestTfmsInParallel>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Program.fs" />

samples/BenchmarkDotNet.Samples/BenchmarkDotNet.Samples.csproj

@@ -14,6 +14,7 @@
     <GenerateProgramFile>false</GenerateProgramFile>
     <!-- Disable parallel tests between TargetFrameworks -->
     <TestTfmsInParallel>false</TestTfmsInParallel>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup Condition=" '$(TargetFrameworkIdentifier)' == '.NETFramework' ">
     <Reference Include="System.Reflection" />

samples/BenchmarkDotNet.Samples/IntroComparableComplexParam.cs

@@ -31,7 +31,16 @@ public ComplexParam(int value, string name)
 
             public int CompareTo(ComplexParam? other) => other == null ? 1 : Value.CompareTo(other.Value);
 
-            public int CompareTo(object obj) => obj is ComplexParam other ? CompareTo(other) : throw new ArgumentException();
+            public int CompareTo(object? obj)
+            {
+                if (obj == null)
+                    return 1;
+
+                if (obj is not ComplexParam other)
+                    throw new ArgumentException();
+
+                return CompareTo(other);
+            }
         }
     }
 }

samples/BenchmarkDotNet.Samples/IntroDotMemoryDiagnoser.cs

@@ -13,8 +13,8 @@ public class IntroDotMemoryDiagnoser
         [Params(1024)]
         public int Size;
 
-        private byte[] dataArray;
-        private IEnumerable<byte> dataEnumerable;
+        private byte[] dataArray = default!;
+        private IEnumerable<byte> dataEnumerable = default!;
 
         [GlobalSetup]
         public void Setup()

samples/BenchmarkDotNet.Samples/IntroMemoryRandomization.cs

@@ -8,8 +8,8 @@ public class IntroMemoryRandomization
         [Params(512 * 4)]
         public int Size;
 
-        private int[] array;
-        private int[] destination;
+        private int[] array = default!;
+        private int[] destination = default!;
 
         [GlobalSetup]
         public void Setup()

samples/BenchmarkDotNet.Samples/IntroOrderManual.cs

@@ -30,10 +30,10 @@ from benchmark in benchmarksCase
 
                 public IEnumerable<BenchmarkCase> GetSummaryOrder(ImmutableArray<BenchmarkCase> benchmarksCase, Summary summary) =>
                     from benchmark in benchmarksCase
-                    orderby summary[benchmark].ResultStatistics.Mean
+                    orderby summary[benchmark]?.ResultStatistics?.Mean
                     select benchmark;
 
-                public string GetHighlightGroupKey(BenchmarkCase benchmarkCase) => null;
+                public string? GetHighlightGroupKey(BenchmarkCase benchmarkCase) => null;
 
                 public string GetLogicalGroupKey(ImmutableArray<BenchmarkCase> allBenchmarksCases, BenchmarkCase benchmarkCase) =>
                     benchmarkCase.Job.DisplayInfo + "_" + benchmarkCase.Parameters.DisplayInfo;

samples/BenchmarkDotNet.Samples/IntroSetupCleanupGlobal.cs

@@ -7,7 +7,7 @@ public class IntroSetupCleanupGlobal
         [Params(10, 100, 1000)]
         public int N;
 
-        private int[] data;
+        private int[] data = default!;
 
         [GlobalSetup]
         public void GlobalSetup()

samples/BenchmarkDotNet.Samples/IntroSmokeValueTypes.cs

@@ -22,10 +22,10 @@ public struct EmptyStruct { }
     [Benchmark] public EmptyStruct ReturnEmptyStruct() => new EmptyStruct();
 
     [Benchmark] public ValueTuple<int> ReturnGenericStructOfValueType() => new ValueTuple<int>(0);
-    [Benchmark] public ValueTuple<object> ReturnGenericStructOfReferenceType() => new ValueTuple<object>(null);
+    [Benchmark] public ValueTuple<object?> ReturnGenericStructOfReferenceType() => new ValueTuple<object?>(null);
 
     [Benchmark] public ValueTask<int> ReturnValueTaskOfValueType() => new ValueTask<int>(0);
-    [Benchmark] public ValueTask<object> ReturnValueTaskOfReferenceType() => new ValueTask<object>(result: null);
+    [Benchmark] public ValueTask<object?> ReturnValueTaskOfReferenceType() => new ValueTask<object?>(result: null);
 
     [Benchmark] public byte ReturnByte() => 0;
     public struct Byte1 { public byte _1; }

samples/BenchmarkDotNet.Samples/IntroThreadingDiagnoser.cs

@@ -11,7 +11,7 @@ public void CompleteOneWorkItem()
         {
             ManualResetEvent done = new ManualResetEvent(initialState: false);
 
-            ThreadPool.QueueUserWorkItem(m => (m as ManualResetEvent).Set(), done);
+            ThreadPool.QueueUserWorkItem(m => (m as ManualResetEvent)?.Set(), done);
 
             done.WaitOne();
         }

samples/BenchmarkDotNet.Samples/IntroWasm.cs

@@ -36,7 +36,7 @@ public static void Run()
 
             WasmRuntime runtime = new WasmRuntime(msBuildMoniker: "net5.0");
             NetCoreAppSettings netCoreAppSettings = new NetCoreAppSettings(
-                targetFrameworkMoniker: "net5.0", runtimeFrameworkVersion: null, name: "Wasm",
+                targetFrameworkMoniker: "net5.0", runtimeFrameworkVersion: "", name: "Wasm",
                 customDotNetCliPath: cliPath);
             IToolchain toolChain = WasmToolchain.From(netCoreAppSettings);