Add [DoesNotReturn] attribute to instruct code coverage about unreach…

…able lines

Build/Build.cs

@@ -163,7 +163,9 @@ class Build : NukeBuild
                 .SetTargetDirectory(RootDirectory / "TestResults" / "reports")
                 .AddReports(RootDirectory / "TestResults/**/coverage.cobertura.xml")
                 .AddReportTypes("HtmlInline_AzurePipelines_Dark", "lcov")
-                .SetClassFilters("-System.Diagnostics.CodeAnalysis.StringSyntaxAttribute")
+                .SetClassFilters(
+                    "-System.Diagnostics.CodeAnalysis.StringSyntaxAttribute",
+                    "-System.Diagnostics.CodeAnalysis.DoesNotReturnAttribute")
                 .SetAssemblyFilters("+FluentAssertions"));
 
             string link = RootDirectory / "TestResults" / "reports" / "index.html";

Src/FluentAssertions/AssertionExtensions.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Data;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq.Expressions;
 using System.Net.Http;
@@ -999,6 +1000,7 @@ public static void Should(this TypeSelectorAssertions _)
             InvalidShouldCall();
         }
 
+        [DoesNotReturn]
         private static void InvalidShouldCall()
         {
             throw new InvalidOperationException("You are asserting the 'AndConstraint' itself. Remove the 'Should()' method directly following 'And'.");

Src/FluentAssertions/Common/Services.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using FluentAssertions.Execution;
 
 namespace FluentAssertions.Common

Src/FluentAssertions/DoesNotReturnAttribute.cs

@@ -0,0 +1,18 @@
+// copied from https://source.dot.net/#System.Private.CoreLib/NullableAttributes.cs
+#if !(NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_0_OR_GREATER)
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+namespace System.Diagnostics.CodeAnalysis
+{
+    /// <summary>Applied to a method that will never return under any circumstance.</summary>
+    [AttributeUsage(AttributeTargets.Method, Inherited = false)]
+#if SYSTEM_PRIVATE_CORELIB
+    public
+#else
+    internal
+#endif
+        sealed class DoesNotReturnAttribute : Attribute
+    {
+    }
+}
+#endif

Src/FluentAssertions/Execution/FallbackTestFramework.cs

@@ -1,3 +1,5 @@
+using System.Diagnostics.CodeAnalysis;
+
 namespace FluentAssertions.Execution
 {
     /// <summary>
@@ -13,6 +15,7 @@ internal class FallbackTestFramework : ITestFramework
         /// <summary>
         /// Throws a framework-specific exception to indicate a failing unit test.
         /// </summary>
+        [DoesNotReturn]
         public void Throw(string message)
         {
             throw new AssertionFailedException(message);

Src/FluentAssertions/Execution/ITestFramework.cs

@@ -1,4 +1,6 @@
-namespace FluentAssertions.Execution
+using System.Diagnostics.CodeAnalysis;
+
+namespace FluentAssertions.Execution
 {
     /// <summary>
     /// Represents an abstraction of a particular test framework such as MSTest, nUnit, etc.
@@ -13,6 +15,7 @@ internal interface ITestFramework
         /// <summary>
         /// Throws a framework-specific exception to indicate a failing unit test.
         /// </summary>
+        [DoesNotReturn]
         void Throw(string message);
     }
 }

Src/FluentAssertions/Execution/LateBoundTestFramework.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
 
@@ -8,6 +9,7 @@ internal abstract class LateBoundTestFramework : ITestFramework
     {
         private Assembly assembly;
 
+        [DoesNotReturn]
         public void Throw(string message)
         {
             Type exceptionType = assembly.GetType(ExceptionFullName);

Src/FluentAssertions/Execution/NSpecFramework.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
 
@@ -27,6 +28,7 @@ public bool IsAvailable
             }
         }
 
+        [DoesNotReturn]
         public void Throw(string message)
         {
             Type exceptionType = assembly.GetType("NSpec.Domain.AssertionException");

Src/FluentAssertions/Execution/TestFrameworkProvider.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using FluentAssertions.Common;
 
@@ -22,6 +23,7 @@ internal static class TestFrameworkProvider
 
         #endregion
 
+        [DoesNotReturn]
         public static void Throw(string message)
         {
             if (testFramework is null)

Src/FluentAssertions/Execution/XUnit2TestFramework.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 
 namespace FluentAssertions.Execution
@@ -25,6 +26,7 @@ public bool IsAvailable
             }
         }
 
+        [DoesNotReturn]
         public void Throw(string message)
         {
             Type exceptionType = assembly.GetType("Xunit.Sdk.XunitException");