Implements support for Repo‑Local MSBuild SDKs via .msbuild/Sdk/<SdkName>/

src/Build.UnitTests/BackEnd/RepoLocalSdkResolver_Tests.cs

@@ -0,0 +1,292 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.IO;
+using Microsoft.Build.Construction;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Shared;
+using Microsoft.Build.UnitTests;
+using Shouldly;
+using Xunit;
+
+using RepoLocalSdkResolver = Microsoft.Build.BackEnd.SdkResolution.RepoLocalSdkResolver;
+using DefaultSdkResolver = Microsoft.Build.BackEnd.SdkResolution.DefaultSdkResolver;
+using SdkResultFactory = Microsoft.Build.BackEnd.SdkResolution.SdkResultFactory;
+
+#nullable disable
+
+namespace Microsoft.Build.Engine.UnitTests.BackEnd
+{
+    public class RepoLocalSdkResolver_Tests : IDisposable
+    {
+        private readonly string _testRoot;
+
+        public RepoLocalSdkResolver_Tests()
+        {
+            _testRoot = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N"));
+            Directory.CreateDirectory(_testRoot);
+        }
+
+        public void Dispose()
+        {
+            if (Directory.Exists(_testRoot))
+            {
+                FileUtilities.DeleteDirectoryNoThrow(_testRoot, recursive: true);
+            }
+        }
+
+        [Theory]
+        [InlineData(".git")]
+        [InlineData(".hg")]
+        [InlineData(".svn")]
+        public void ResolveSdkFromRepoLocalDirectory(string repoMarker)
+        {
+            // Arrange
+            string repoRoot = Path.Combine(_testRoot, "repo");
+            Directory.CreateDirectory(repoRoot);
+            Directory.CreateDirectory(Path.Combine(repoRoot, repoMarker));
+
+            string sdkName = "My.Test.Sdk";
+            string sdkPath = Path.Combine(repoRoot, ".msbuild", "Sdk", sdkName, "Sdk");
+            Directory.CreateDirectory(sdkPath);
+
+            // Create Sdk.props and Sdk.targets to make it a valid SDK
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.props"), "<Project />");
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.targets"), "<Project />");
+
+            string projectPath = Path.Combine(repoRoot, "src", "Project.csproj");
+            Directory.CreateDirectory(Path.GetDirectoryName(projectPath));
+            File.WriteAllText(projectPath, "<Project />");
+
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(projectPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeTrue();
+            result.Path.ShouldBe(sdkPath);
+        }
+
+        [Fact]
+        public void DoesNotResolveSdkWhenNoRepoMarkerFound()
+        {
+            // Arrange
+            string projectDir = Path.Combine(_testRoot, "project");
+            Directory.CreateDirectory(projectDir);
+
+            string projectPath = Path.Combine(projectDir, "Project.csproj");
+            File.WriteAllText(projectPath, "<Project />");
+
+            string sdkName = "My.Test.Sdk";
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(projectPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeFalse();
+        }
+
+        [Fact]
+        public void DoesNotResolveSdkWhenSdkDirectoryDoesNotExist()
+        {
+            // Arrange
+            string repoRoot = Path.Combine(_testRoot, "repo");
+            Directory.CreateDirectory(repoRoot);
+            Directory.CreateDirectory(Path.Combine(repoRoot, ".git"));
+
+            string projectPath = Path.Combine(repoRoot, "src", "Project.csproj");
+            Directory.CreateDirectory(Path.GetDirectoryName(projectPath));
+            File.WriteAllText(projectPath, "<Project />");
+
+            string sdkName = "My.Test.Sdk";
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(projectPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeFalse();
+        }
+
+        [Fact]
+        public void FailsWhenSdkDirectoryExistsButNoPropsOrTargets()
+        {
+            // Arrange
+            string repoRoot = Path.Combine(_testRoot, "repo");
+            Directory.CreateDirectory(repoRoot);
+            Directory.CreateDirectory(Path.Combine(repoRoot, ".git"));
+
+            string sdkName = "My.Test.Sdk";
+            string sdkPath = Path.Combine(repoRoot, ".msbuild", "Sdk", sdkName, "Sdk");
+            Directory.CreateDirectory(sdkPath);
+            // Don't create Sdk.props or Sdk.targets
+
+            string projectPath = Path.Combine(repoRoot, "src", "Project.csproj");
+            Directory.CreateDirectory(Path.GetDirectoryName(projectPath));
+            File.WriteAllText(projectPath, "<Project />");
+
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(projectPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeFalse();
+        }
+
+        [Fact]
+        public void SucceedsWithOnlyPropsFile()
+        {
+            // Arrange
+            string repoRoot = Path.Combine(_testRoot, "repo");
+            Directory.CreateDirectory(repoRoot);
+            Directory.CreateDirectory(Path.Combine(repoRoot, ".git"));
+
+            string sdkName = "My.Test.Sdk";
+            string sdkPath = Path.Combine(repoRoot, ".msbuild", "Sdk", sdkName, "Sdk");
+            Directory.CreateDirectory(sdkPath);
+
+            // Create only Sdk.props
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.props"), "<Project />");
+
+            string projectPath = Path.Combine(repoRoot, "src", "Project.csproj");
+            Directory.CreateDirectory(Path.GetDirectoryName(projectPath));
+            File.WriteAllText(projectPath, "<Project />");
+
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(projectPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeTrue();
+            result.Path.ShouldBe(sdkPath);
+        }
+
+        [Fact]
+        public void SucceedsWithOnlyTargetsFile()
+        {
+            // Arrange
+            string repoRoot = Path.Combine(_testRoot, "repo");
+            Directory.CreateDirectory(repoRoot);
+            Directory.CreateDirectory(Path.Combine(repoRoot, ".git"));
+
+            string sdkName = "My.Test.Sdk";
+            string sdkPath = Path.Combine(repoRoot, ".msbuild", "Sdk", sdkName, "Sdk");
+            Directory.CreateDirectory(sdkPath);
+
+            // Create only Sdk.targets
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.targets"), "<Project />");
+
+            string projectPath = Path.Combine(repoRoot, "src", "Project.csproj");
+            Directory.CreateDirectory(Path.GetDirectoryName(projectPath));
+            File.WriteAllText(projectPath, "<Project />");
+
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(projectPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeTrue();
+            result.Path.ShouldBe(sdkPath);
+        }
+
+        [Fact]
+        public void FindsRepoRootMultipleLevelsUp()
+        {
+            // Arrange
+            string repoRoot = Path.Combine(_testRoot, "repo");
+            Directory.CreateDirectory(repoRoot);
+            Directory.CreateDirectory(Path.Combine(repoRoot, ".git"));
+
+            string sdkName = "My.Test.Sdk";
+            string sdkPath = Path.Combine(repoRoot, ".msbuild", "Sdk", sdkName, "Sdk");
+            Directory.CreateDirectory(sdkPath);
+
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.props"), "<Project />");
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.targets"), "<Project />");
+
+            // Create project several levels deep
+            string projectPath = Path.Combine(repoRoot, "src", "subfolder", "nested", "Project.csproj");
+            Directory.CreateDirectory(Path.GetDirectoryName(projectPath));
+            File.WriteAllText(projectPath, "<Project />");
+
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(projectPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeTrue();
+            result.Path.ShouldBe(sdkPath);
+        }
+
+        [Fact]
+        public void UsesSolutionPathWhenProjectPathIsNull()
+        {
+            // Arrange
+            string repoRoot = Path.Combine(_testRoot, "repo");
+            Directory.CreateDirectory(repoRoot);
+            Directory.CreateDirectory(Path.Combine(repoRoot, ".git"));
+
+            string sdkName = "My.Test.Sdk";
+            string sdkPath = Path.Combine(repoRoot, ".msbuild", "Sdk", sdkName, "Sdk");
+            Directory.CreateDirectory(sdkPath);
+
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.props"), "<Project />");
+            File.WriteAllText(Path.Combine(sdkPath, "Sdk.targets"), "<Project />");
+
+            string solutionPath = Path.Combine(repoRoot, "MySolution.sln");
+            File.WriteAllText(solutionPath, "");
+
+            var resolver = new RepoLocalSdkResolver();
+            var context = new MockSdkResolverContext(null, solutionPath);
+            var factory = new SdkResultFactory(new SdkReference(sdkName, null, null));
+
+            // Act
+            var result = resolver.Resolve(new SdkReference(sdkName, null, null), context, factory);
+
+            // Assert
+            result.Success.ShouldBeTrue();
+            result.Path.ShouldBe(sdkPath);
+        }
+
+        [Fact]
+        public void ResolverHasHigherPriorityThanDefault()
+        {
+            // This test verifies that RepoLocalSdkResolver has a higher priority (lower number)
+            // than DefaultSdkResolver so that repo-local SDKs take precedence
+            var repoLocalResolver = new RepoLocalSdkResolver();
+            var defaultResolver = new DefaultSdkResolver();
+
+            repoLocalResolver.Priority.ShouldBeLessThan(defaultResolver.Priority);
+        }
+
+        private sealed class MockSdkResolverContext : Microsoft.Build.Framework.SdkResolverContext
+        {
+            public MockSdkResolverContext(string projectFilePath, string solutionFilePath = null)
+            {
+                ProjectFilePath = projectFilePath;
+                SolutionFilePath = solutionFilePath;
+            }
+        }
+    }
+}

src/Build.UnitTests/BackEnd/SdkResolverLoader_Tests.cs

@@ -46,7 +46,7 @@ public void AssertDefaultLoaderReturnsDefaultResolvers()
 
             var resolvers = loader.LoadAllResolvers(new MockElementLocation("file"));
 
-            resolvers.Select(i => i.GetType().FullName).ShouldBe(new[] { typeof(DefaultSdkResolver).FullName });
+            resolvers.Select(i => i.GetType().FullName).ShouldBe(new[] { typeof(RepoLocalSdkResolver).FullName, typeof(DefaultSdkResolver).FullName });
 
             _logger.ErrorCount.ShouldBe(0);
             _logger.WarningCount.ShouldBe(0);