private static Compilation CreateTestCompilation()
    => CSharpCompilation.Create(
        assemblyName: "ConsoleApplication",
        syntaxTrees: new[] {
            SyntaxTreeFromPath(@"Program.cs"),
            SyntaxTreeFromPath(@"InitializerRewriter.cs")
        },
        references: new[] {
            MetadataReferenceFromType<object>(), // mscorlib
            MetadataReferenceFromType<SyntaxTree>(), // CodeAnalysis
            MetadataReferenceFromType<CSharpSyntaxTree>() // CSharpCodeAnalysis
        },
        options: new CSharpCompilationOptions(OutputKind.ConsoleApplication)
    );

private static SyntaxTree SyntaxTreeFromPath(string path)
    => CSharpSyntaxTree.ParseText(File.ReadAllText(path)).WithFilePath(path);

private static MetadataReference MetadataReferenceFromType<T>()
    => MetadataReference.CreateFromFile(typeof(T).GetTypeInfo().Assembly.Location);