C#: Re-factor the hardcoded package names into a separate class.

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/Assets.cs

@@ -14,14 +14,6 @@ namespace Semmle.Extraction.CSharp.DependencyFetching
     {
         private readonly ProgressMonitor progressMonitor;
 
-        private static readonly string[] netFrameworks = new[] {
-            "microsoft.aspnetcore.app.ref",
-            "microsoft.netcore.app.ref",
-            "microsoft.netframework.referenceassemblies",
-            "microsoft.windowsdesktop.app.ref",
-            "netstandard.library.ref"
-        };
-
         internal Assets(ProgressMonitor progressMonitor)
         {
             this.progressMonitor = progressMonitor;
@@ -109,7 +101,7 @@ namespace Semmle.Extraction.CSharp.DependencyFetching
                     }
 
                     // If this is a .NET framework reference then include everything.
-                    if (netFrameworks.Any(framework => name.StartsWith(framework)))
+                    if (FrameworkPackageNames.AllFrameworks.Any(framework => name.StartsWith(framework)))
                     {
                         dependencies.AddFramework(name);
                     }

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DependencyManager.cs

@@ -232,13 +232,7 @@ namespace Semmle.Extraction.CSharp.DependencyFetching
         {
             // Multiple dotnet framework packages could be present.
             // The order of the packages is important, we're adding the first one that is present in the nuget cache.
-            var packagesInPrioOrder = new string[]
-            {
-                "microsoft.netcore.app.ref", // net7.0, ... net5.0, netcoreapp3.1, netcoreapp3.0
-                "microsoft.netframework.referenceassemblies.", // net48, ..., net20
-                "netstandard.library.ref", // netstandard2.1
-                "netstandard.library" // netstandard2.0
-            };
+            var packagesInPrioOrder = FrameworkPackageNames.NetFrameworks;
 
             var frameworkPath = packagesInPrioOrder
                     .Select((s, index) => (Index: index, Path: GetPackageDirectory(s)))
@@ -308,7 +302,7 @@ namespace Semmle.Extraction.CSharp.DependencyFetching
             }
 
             // First try to find ASP.NET Core assemblies in the NuGet packages
-            if (GetPackageDirectory("microsoft.aspnetcore.app.ref") is string aspNetCorePackage)
+            if (GetPackageDirectory(FrameworkPackageNames.AspNetCoreFramework) is string aspNetCorePackage)
             {
                 progressMonitor.LogInfo($"Found ASP.NET Core in NuGet packages. Not adding installation directory.");
                 dllPaths.Add(aspNetCorePackage);
@@ -322,7 +316,7 @@ namespace Semmle.Extraction.CSharp.DependencyFetching
 
         private void AddMicrosoftWindowsDesktopDlls(ISet<string> dllPaths)
         {
-            if (GetPackageDirectory("microsoft.windowsdesktop.app.ref") is string windowsDesktopApp)
+            if (GetPackageDirectory(FrameworkPackageNames.WindowsDesktopFramework) is string windowsDesktopApp)
             {
                 progressMonitor.LogInfo($"Found Windows Desktop App in NuGet packages.");
                 dllPaths.Add(windowsDesktopApp);

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/FrameworkPackageNames.cs

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Semmle.Extraction.CSharp.DependencyFetching
+{
+    internal static class FrameworkPackageNames
+    {
+        // The order of the packages is important.
+        public static readonly string[] NetFrameworks = new string[]
+            {
+                "microsoft.netcore.app.ref", // net7.0, ... net5.0, netcoreapp3.1, netcoreapp3.0
+                "microsoft.netframework.referenceassemblies.", // net48, ..., net20
+                "netstandard.library.ref", // netstandard2.1
+                "netstandard.library" // netstandard2.0
+            };
+
+        public static string AspNetCoreFramework =>
+            "microsoft.aspnetcore.app.ref";
+
+        public static string WindowsDesktopFramework =>
+            "microsoft.windowsdesktop.app.ref";
+
+        public static readonly IEnumerable<string> AllFrameworks =
+            NetFrameworks
+                .Union(new string[] { AspNetCoreFramework, WindowsDesktopFramework });
+    }
+}

csharp/extractor/Semmle.Extraction.Tests/Assets.cs

@@ -25,7 +25,7 @@ namespace Semmle.Extraction.Tests
             Assert.Equal(6, dependencies.Packages.Count());
 
             var normalizedPaths = dependencies.Paths.Select(FixExpectedPathOnWindows);
-            // Required references
+            // Used references
             Assert.Contains("castle.core/4.4.1/lib/netstandard1.5/Castle.Core.dll", normalizedPaths);
             Assert.Contains("castle.core/4.4.1/lib/netstandard1.5/Castle.Core2.dll", normalizedPaths);
             Assert.Contains("json.net/1.0.33/lib/netstandard2.0/Json.Net.dll", normalizedPaths);
@@ -57,10 +57,10 @@ namespace Semmle.Extraction.Tests
             Assert.Equal(2, dependencies.Paths.Count());
 
             var normalizedPaths = dependencies.Paths.Select(FixExpectedPathOnWindows);
-            // Required references
+            // Used references
             Assert.Contains("microsoft.netframework.referenceassemblies/1.0.3", normalizedPaths);
             Assert.Contains("microsoft.netframework.referenceassemblies.net48/1.0.3", normalizedPaths);
-            // Used packages
+            // Used frameworks
             Assert.Contains("microsoft.netframework.referenceassemblies", dependencies.Packages);
             Assert.Contains("microsoft.netframework.referenceassemblies.net48", dependencies.Packages);
         }