feat: Restore support for aliases via Buildalyzer

integrationtest/TargetProjects/NetCore/TargetProject/Constructs/Csharp1.cs

@@ -1,3 +1,5 @@
+extern alias TheLib;
+
 using System.Linq;
 
 namespace TargetProject.Constructs;

integrationtest/TargetProjects/NetCore/TargetProject/StrykerFeatures/UseAssert.cs

@@ -1,4 +1,7 @@
+extern alias TheLog;
+
 using System.Diagnostics;
+using TheLog::Serilog.Configuration;
 
 namespace TargetProject.StrykerFeatures;
 public class UseAssert
@@ -7,6 +10,8 @@ public class UseAssert
 
     public void IncrementCounter()
     {
+        // this is only to check for alias support
+        var test = new BatchingOptions();
         _counter++;
         Debug.Assert(_counter > 0, "Counter should be greater than 0");
     }

integrationtest/TargetProjects/NetCore/TargetProject/TargetProject.csproj

@@ -21,14 +21,19 @@
       project reference path (it also ensures the import above was properly
       evaluated).
     -->
-    <ProjectReference Include="..\$(LibraryDir)\Library.csproj" />
+    <ProjectReference Include="..\$(LibraryDir)\Library.csproj">
+      <Aliases>TheLib</Aliases>
+    </ProjectReference>
       <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleTo">
         <_Parameter1>$(AssemblyName).Tests</_Parameter1>
       </AssemblyAttribute>
   </ItemGroup>
 
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.Common" Version="4.11.0" />
+    <PackageReference Include="Serilog" Version="4.1.0">
+      <Aliases>TheLog</Aliases>
+    </PackageReference>
   </ItemGroup>
 
   <ItemGroup>

src/Stryker.Core/Stryker.Core.UnitTest/Compiling/CSharpCompilingProcessTests.cs

@@ -75,8 +75,8 @@ public int Subtract(int first, int second)
     public void CompilingProcessTests_ShouldSupportPackageReferenceAliases()
     {
         var syntaxTree = CSharpSyntaxTree.ParseText(@"
-extern alias TestAlias;
-using TestAlias::System;
+extern alias TheAlias;
+using TheAlias::System;
 
 namespace ExampleProject
 {
@@ -88,6 +88,10 @@ public int Subtract(int first, int second)
     }
 }
 }");
+        var alias = new Dictionary<string, ImmutableArray<string>>();
+        var immutableArray = ImmutableArray.Create("TheAlias");
+        alias[typeof(object).Assembly.Location]=immutableArray;
+
         var input = new MutationTestInput()
         {
             SourceProjectInfo = new SourceProjectInfo
@@ -101,21 +105,8 @@ public int Subtract(int first, int second)
                         { "TargetFileName", "TargetFileName.dll" },
                     },
                     // add a reference to system so the example code can compile
-                    references: new[] { typeof(object).Assembly.Location },
-                    packageReferences: new ReadOnlyDictionary<string, IReadOnlyDictionary<string, string>>(
-                         new Dictionary<string, IReadOnlyDictionary<string, string>>
-                         {
-                             {
-                                 typeof(object).Assembly.GetName().Name,
-                                 new ReadOnlyDictionary<string, string>(
-                                     new Dictionary<string, string>
-                                     {
-                                         { "Aliases", "TestAlias" }
-                                     }
-                                 )
-                             }
-                         }
-                    )
+                    references: [typeof(object).Assembly.Location],
+                    aliases: alias.ToImmutableDictionary()
                 ).Object
             }
         };

src/Stryker.Core/Stryker.Core.UnitTest/TestHelper.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.IO;
 using Buildalyzer;
 using Moq;
@@ -15,7 +16,8 @@ public static Mock<IAnalyzerResult> SetupProjectAnalyzerResult(Dictionary<string
         IReadOnlyDictionary<string, IReadOnlyDictionary<string, string>> packageReferences = null,
         string[] references = null,
         string[] preprocessorSymbols = null,
-        string[] analyzers = null
+        string[] analyzers = null,
+        ImmutableDictionary<string,  ImmutableArray<string>> aliases = null
     )
     {
         var analyzerResultMock = new Mock<IAnalyzerResult>();
@@ -67,7 +69,9 @@ public static Mock<IAnalyzerResult> SetupProjectAnalyzerResult(Dictionary<string
         {
             analyzerResultMock.Setup(x => x.AnalyzerReferences).Returns(analyzers);
         }
+        aliases ??= ImmutableDictionary<string, ImmutableArray<string>>.Empty;
         analyzerResultMock.Setup(x => x.Items).Returns(new Dictionary<string, IProjectItem[]>());
+        analyzerResultMock.Setup(x => x.ReferenceAliases).Returns(aliases);
 
         return analyzerResultMock;
     }

src/Stryker.Core/Stryker.Core/Initialisation/Buildalyzer/IAnalyzerResultExtensions.cs

@@ -107,28 +107,14 @@ public static IEnumerable<MetadataReference> LoadReferences(this IAnalyzerResult
     {
         foreach (var reference in analyzerResult.References)
         {
-            var referenceFileNameWithoutExtension = Path.GetFileNameWithoutExtension(reference);
-            string packageWithAlias = null;
 
-            if (analyzerResult.PackageReferences is not null)
+            if (!analyzerResult.ReferenceAliases.TryGetValue(reference, out var aliases))
             {
-                // Check for any matching package reference with an alias using LINQ
-                packageWithAlias = analyzerResult.PackageReferences
-                    .Where(pr => pr.Key == referenceFileNameWithoutExtension && pr.Value.ContainsKey("Aliases"))
-                    .Select(pr => pr.Value["Aliases"])
-                    .FirstOrDefault();
-            }
-
-            if (packageWithAlias is not null)
-            {
-                // Return the reference with the alias
-                yield return MetadataReference.CreateFromFile(reference).WithAliases(new[] { packageWithAlias });
-            }
-            else
-            {
-                // If no alias is found, return the reference without aliases
-                yield return MetadataReference.CreateFromFile(reference);
+                aliases = [];
             }
+
+            // If no alias is found, return the reference without aliases
+            yield return MetadataReference.CreateFromFile(reference).WithAliases(aliases);
         }
     }