Add unit tests for Go version detection and fix exception handling

Co-authored-by: tommasodotNET <12819039+tommasodotNET@users.noreply.github.com>

Author: Copilot

src/CommunityToolkit.Aspire.Hosting.Golang/CommunityToolkit.Aspire.Hosting.Golang.csproj

@@ -8,6 +8,10 @@
     <Compile Include="$(SharedDir)\PathNormalizer.cs" Link="Utils\PathNormalizer.cs" />
   </ItemGroup>
 
+  <ItemGroup>
+    <InternalsVisibleTo Include="CommunityToolkit.Aspire.Hosting.Golang.Tests" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Aspire.Hosting" />
   </ItemGroup>

src/CommunityToolkit.Aspire.Hosting.Golang/GolangAppHostingExtension.cs

@@ -147,7 +147,7 @@ private static string GetDefaultGoBaseImage(string workingDirectory, IServicePro
     /// <param name="workingDirectory">The working directory of the Go project.</param>
     /// <param name="logger">The logger for diagnostic messages.</param>
     /// <returns>The detected Go version as a string, or <c>null</c> if no version is detected.</returns>
-    private static string? DetectGoVersion(string workingDirectory, ILogger logger)
+    internal static string? DetectGoVersion(string workingDirectory, ILogger logger)
     {
         // Check go.mod file
         var goModPath = Path.Combine(workingDirectory, "go.mod");
@@ -171,9 +171,17 @@ private static string GetDefaultGoBaseImage(string workingDirectory, IServicePro
                     }
                 }
             }
-            catch (Exception ex)
+            catch (IOException ex)
             {
-                logger.LogDebug(ex, "Failed to parse go.mod file");
+                logger.LogDebug(ex, "Failed to parse go.mod file due to IO error");
+            }
+            catch (UnauthorizedAccessException ex)
+            {
+                logger.LogDebug(ex, "Failed to parse go.mod file due to unauthorized access");
+            }
+            catch (RegexMatchTimeoutException ex)
+            {
+                logger.LogDebug(ex, "Failed to parse go.mod file due to regex timeout");
             }
         }
 
@@ -193,8 +201,11 @@ private static string GetDefaultGoBaseImage(string workingDirectory, IServicePro
             using var process = Process.Start(startInfo);
             if (process != null)
             {
-                var output = process.StandardOutput.ReadToEnd();
+                // Read both output and error asynchronously to avoid deadlock
+                var outputTask = process.StandardOutput.ReadToEndAsync();
+                var errorTask = process.StandardError.ReadToEndAsync();
                 process.WaitForExit();
+                var output = outputTask.GetAwaiter().GetResult();
 
                 if (process.ExitCode == 0)
                 {
@@ -209,9 +220,13 @@ private static string GetDefaultGoBaseImage(string workingDirectory, IServicePro
                 }
             }
         }
-        catch (Exception ex)
+        catch (IOException ex)
+        {
+            logger.LogDebug(ex, "Failed to detect Go version from installed toolchain due to IO error");
+        }
+        catch (System.ComponentModel.Win32Exception ex)
         {
-            logger.LogDebug(ex, "Failed to detect Go version from installed toolchain");
+            logger.LogDebug(ex, "Failed to detect Go version from installed toolchain - go command not found or not executable");
         }
 
         logger.LogDebug("No Go version detected, will use default version");

tests/CommunityToolkit.Aspire.Hosting.Golang.Tests/GoVersionDetectionTests.cs

@@ -0,0 +1,147 @@
+using Aspire.Hosting;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace CommunityToolkit.Aspire.Hosting.Golang.Tests;
+
+public class GoVersionDetectionTests
+{
+    [Fact]
+    public void DetectGoVersionFromGoMod()
+    {
+        // Arrange
+        var workingDirectory = Path.GetFullPath(Path.Combine("..", "..", "..", "..", "..", "examples", "golang", "gin-api"));
+        var logger = NullLogger.Instance;
+
+        // Act
+        var version = GolangAppHostingExtension.DetectGoVersion(workingDirectory, logger);
+
+        // Assert
+        Assert.NotNull(version);
+        Assert.Equal("1.22", version);
+    }
+
+    [Fact]
+    public void DetectGoVersionFromGoMod_NonExistentDirectory()
+    {
+        // Arrange
+        var workingDirectory = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+        var logger = NullLogger.Instance;
+
+        // Act
+        var version = GolangAppHostingExtension.DetectGoVersion(workingDirectory, logger);
+
+        // Assert - should fall back to checking installed toolchain or return null
+        // We don't assert a specific value because it depends on the system's Go installation
+        Assert.True(version == null || !string.IsNullOrEmpty(version));
+    }
+
+    [Fact]
+    public void DetectGoVersionFromGoMod_WithPatchVersion()
+    {
+        // Arrange - Create a temporary directory with a go.mod file
+        var tempDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+        Directory.CreateDirectory(tempDir);
+        try
+        {
+            var goModPath = Path.Combine(tempDir, "go.mod");
+            File.WriteAllText(goModPath, @"module testmodule
+
+go 1.21.5
+
+require (
+    github.com/example/package v1.0.0
+)
+");
+
+            var logger = NullLogger.Instance;
+
+            // Act
+            var version = GolangAppHostingExtension.DetectGoVersion(tempDir, logger);
+
+            // Assert
+            Assert.NotNull(version);
+            Assert.Equal("1.21", version);
+        }
+        finally
+        {
+            // Cleanup
+            if (Directory.Exists(tempDir))
+            {
+                Directory.Delete(tempDir, true);
+            }
+        }
+    }
+
+    [Fact]
+    public void DetectGoVersionFromGoMod_WithMajorMinorOnly()
+    {
+        // Arrange - Create a temporary directory with a go.mod file
+        var tempDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+        Directory.CreateDirectory(tempDir);
+        try
+        {
+            var goModPath = Path.Combine(tempDir, "go.mod");
+            File.WriteAllText(goModPath, @"module testmodule
+
+go 1.20
+
+require (
+    github.com/example/package v1.0.0
+)
+");
+
+            var logger = NullLogger.Instance;
+
+            // Act
+            var version = GolangAppHostingExtension.DetectGoVersion(tempDir, logger);
+
+            // Assert
+            Assert.NotNull(version);
+            Assert.Equal("1.20", version);
+        }
+        finally
+        {
+            // Cleanup
+            if (Directory.Exists(tempDir))
+            {
+                Directory.Delete(tempDir, true);
+            }
+        }
+    }
+
+    [Fact]
+    public void DetectGoVersionFromGoMod_InvalidFormat()
+    {
+        // Arrange - Create a temporary directory with an invalid go.mod file
+        var tempDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
+        Directory.CreateDirectory(tempDir);
+        try
+        {
+            var goModPath = Path.Combine(tempDir, "go.mod");
+            File.WriteAllText(goModPath, @"module testmodule
+
+go invalid
+
+require (
+    github.com/example/package v1.0.0
+)
+");
+
+            var logger = NullLogger.Instance;
+
+            // Act
+            var version = GolangAppHostingExtension.DetectGoVersion(tempDir, logger);
+
+            // Assert - should fall back to checking installed toolchain or return null
+            Assert.True(version == null || !string.IsNullOrEmpty(version));
+        }
+        finally
+        {
+            // Cleanup
+            if (Directory.Exists(tempDir))
+            {
+                Directory.Delete(tempDir, true);
+            }
+        }
+    }
+}