feat(slnx): support new solution format (#21)

Author: 616b2f

src/bsp-server/BuildHelper.cs

@@ -9,14 +9,16 @@ namespace dotnet_bsp;
 
 internal static class BuildHelper
 {
+    public static string[] SolutionFileExtensions = [ ".sln", ".slnx" ];
+
     internal static IEnumerable<string> ExtractProjectsFromSolutions(BuildTargetIdentifier[] targets)
     {
         var projList = targets
             .Where(x => Path.GetExtension(x.ToString()) == ".csproj")
             .Select(x => x.Uri.AbsolutePath)
             .ToList();
         var slnList = targets
-            .Where(x => Path.GetExtension(x.ToString()) == ".sln");
+            .Where(x => SolutionFileExtensions.Contains(Path.GetExtension(x.ToString())));
         foreach (var target in slnList)
         {
             var slnFile = SolutionFile.Parse(target.ToString());

src/bsp-server/Handlers/WorkspaceBuildTargetsHandler.cs

@@ -42,7 +42,8 @@ private IReadOnlyList<BuildTarget> GetBuildTargetsInWorkspace(string workspacePa
         logger.LogInformation("Search solution files in: {}", workspacePath);
         //TODO: think about the implications to search for all sln files in workspace
         var slnFilePath = Directory
-            .GetFiles(workspacePath, "*.sln")
+            .GetFiles(workspacePath)
+            .Where(x => BuildHelper.SolutionFileExtensions.Contains(Path.GetExtension(x)))
             .Take(1)
             .SingleOrDefault();
         var projectFiles = new List<string>();