feat: enhance MsBuildHelper to locate output assemblies by probing multiple configurations, improving consistency for local and CI runs

Author: V0v1kkk

DotNetMetadataMcpServer/MsBuildHelper.cs

@@ -35,38 +35,84 @@ public MsBuildHelper(ILogger<MsBuildHelper>? logger = null)
         }
 
         var project = new Project(csprojPath, null, null, projectCollection);
-        project.SetProperty("Configuration", configuration);
 
-        var assemblyName = project.GetPropertyValue("AssemblyName");
-        var outputPath = project.GetPropertyValue("OutputPath")
-            .Replace('\\', Path.DirectorySeparatorChar)
-            .Replace('/', Path.DirectorySeparatorChar);
-
-        var targetFramework = project.GetPropertyValue("TargetFramework");
+        // Try the requested configuration first, then fall back to the most common alternatives.
+        var configurationsToTry = new List<string>();
+        void addIfMissing(string cfg)
+        {
+            if (!configurationsToTry.Contains(cfg, StringComparer.OrdinalIgnoreCase))
+            {
+                configurationsToTry.Add(cfg);
+            }
+        }
 
-        if (string.IsNullOrWhiteSpace(assemblyName))
-            assemblyName = Path.GetFileNameWithoutExtension(csprojPath);
+        addIfMissing(configuration);
+        addIfMissing("Release");
+        addIfMissing("Debug");
 
-        if (string.IsNullOrWhiteSpace(outputPath))
-            outputPath = Path.Combine("bin", configuration);
+        string? finalAsmPath = null;
+        string? chosenConfiguration = null;
+        string assemblyName;
+        string targetFramework;
 
         var projDir = Path.GetDirectoryName(Path.GetFullPath(csprojPath)) ?? "";
-        var fullOutputPath = Path.GetFullPath(Path.Combine(projDir, outputPath));
 
-        string? finalAsmPath = null;
-        foreach (var ext in new[] { ".dll", ".exe" })
+        foreach (var cfg in configurationsToTry)
         {
-            var candidate = Path.Combine(fullOutputPath, assemblyName + ext);
-            if (File.Exists(candidate))
+            project.SetProperty("Configuration", cfg);
+
+            assemblyName = project.GetPropertyValue("AssemblyName");
+            if (string.IsNullOrWhiteSpace(assemblyName))
+            {
+                assemblyName = Path.GetFileNameWithoutExtension(csprojPath);
+            }
+
+            var outputPath = project.GetPropertyValue("OutputPath")
+                .Replace('\\', Path.DirectorySeparatorChar)
+                .Replace('/', Path.DirectorySeparatorChar);
+            if (string.IsNullOrWhiteSpace(outputPath))
+            {
+                outputPath = Path.Combine("bin", cfg);
+            }
+
+            targetFramework = project.GetPropertyValue("TargetFramework");
+
+            var fullOutputPath = Path.GetFullPath(Path.Combine(projDir, outputPath));
+            foreach (var ext in new[] { ".dll", ".exe" })
+            {
+                var candidate = Path.Combine(fullOutputPath, assemblyName + ext);
+                if (File.Exists(candidate))
+                {
+                    finalAsmPath = candidate;
+                    chosenConfiguration = cfg;
+                    break;
+                }
+            }
+
+            if (finalAsmPath != null)
             {
-                finalAsmPath = candidate;
                 break;
             }
         }
+
+        // If not found, fall back to a reasonable default path for the originally requested configuration
+        assemblyName = project.GetPropertyValue("AssemblyName");
+        if (string.IsNullOrWhiteSpace(assemblyName))
+        {
+            assemblyName = Path.GetFileNameWithoutExtension(csprojPath);
+        }
+        targetFramework = project.GetPropertyValue("TargetFramework");
         if (finalAsmPath == null)
         {
-            finalAsmPath = Path.Combine(fullOutputPath, assemblyName + ".dll");
-            _logger.LogWarning("Assembly not found, assume {0}", finalAsmPath);
+            var fallbackOutput = project.GetPropertyValue("OutputPath");
+            if (string.IsNullOrWhiteSpace(fallbackOutput))
+            {
+                fallbackOutput = Path.Combine("bin", configuration);
+            }
+            var fullFallback = Path.GetFullPath(Path.Combine(projDir, fallbackOutput));
+            finalAsmPath = Path.Combine(fullFallback, assemblyName + ".dll");
+            _logger.LogWarning("Assembly not found for configurations [{Configs}], assuming {Path}",
+                string.Join(", ", configurationsToTry), finalAsmPath);
         }
 
         // Search for project.assets.json

readme.md

@@ -81,6 +81,16 @@ Replace `/path/to/DotNetMetadataMcpServer` with the actual path to the published
 - **The project must be built before scanning.** The server relies on compiled assemblies to extract type information, so make sure to build your project before using the tools.
 - **The tool doesn't follow references to other projects.** It only inspects the specified project and its NuGet dependencies. If you need to analyze multiple projects, you'll need to scan each one separately.
 
+### How project outputs are located
+
+When scanning a project, the server needs the compiled assembly path. `MsBuildHelper` evaluates the project and attempts to locate the output assembly by probing configurations in this order:
+
+- the requested configuration (by default Debug), then
+- Release, and if still not found,
+- falls back to checking Debug again as a safe default.
+
+The first existing output wins. If no output is found, a reasonable default path is assumed and a warning is logged. This makes local runs (often Debug) and CI runs (often Release) behave consistently. Ensure you build the project in one of these configurations before scanning.
+
 ## Usage
 
 The server provides five main tools that can be used by AI agents: