Support tests using net5.0

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test/StyleCop.Analyzers.Test.csproj

@@ -23,8 +23,11 @@
     <PackageReference Include="System.ValueTuple" Version="4.5.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1" PrivateAssets="all" />
+
+    <!-- Make sure NuGet can parse the 'net5.0' TFM -->
+    <PackageReference Include="NuGet.Frameworks" Version="5.6.0" />
   </ItemGroup>
-  
+
   <ItemGroup>
     <ProjectReference Include="..\StyleCop.Analyzers.CodeFixes\StyleCop.Analyzers.CodeFixes.csproj" />
     <ProjectReference Include="..\StyleCop.Analyzers\StyleCop.Analyzers.csproj" />

StyleCop.Analyzers/StyleCop.Analyzers.Test/Verifiers/GenericAnalyzerTest.cs

@@ -5,6 +5,7 @@ namespace StyleCop.Analyzers.Test.Verifiers
 {
     using System;
     using System.Collections.Immutable;
+    using System.IO;
     using System.Threading;
     using System.Threading.Tasks;
     using Microsoft.CodeAnalysis;
@@ -16,6 +17,8 @@ internal static class GenericAnalyzerTest
     {
         internal static readonly ReferenceAssemblies ReferenceAssemblies;
 
+        internal static readonly ReferenceAssemblies ReferenceAssembliesNet50;
+
         private static readonly Lazy<IExportProviderFactory> ExportProviderFactory;
 
         static GenericAnalyzerTest()
@@ -33,6 +36,10 @@ static GenericAnalyzerTest()
                 new PackageIdentity("Microsoft.CodeAnalysis.CSharp", codeAnalysisTestVersion),
                 new PackageIdentity("System.ValueTuple", "4.5.0")));
 
+            ReferenceAssembliesNet50 =
+                new ReferenceAssemblies("net5.0", new PackageIdentity("Microsoft.NETCore.App.Ref", "5.0.0-rc.1.20451.14"), Path.Combine("ref", "net5.0"))
+                    .AddPackages(ImmutableArray.Create(new PackageIdentity("Microsoft.CodeAnalysis.CSharp", codeAnalysisTestVersion)));
+
             ExportProviderFactory = new Lazy<IExportProviderFactory>(
                 () =>
                 {