Load before/after.{solutionName}.sln.targets for .slnx (#11535)

added test checking that targets from these files are included in the project

Author: surayya-MS

src/Build.UnitTests/Construction/SolutionFile_NewParser_Tests.cs

@@ -144,7 +144,7 @@ private static SolutionFile ParseSolutionHelper(string solutionFileContents, boo
             }
         }
 
-        private static string ConvertToSlnx(string slnPath)
+        internal static string ConvertToSlnx(string slnPath)
         {
             string slnxPath = slnPath + "x";
             ISolutionSerializer serializer = SolutionSerializers.GetSerializerByMoniker(slnPath).ShouldNotBeNull();

src/Build.UnitTests/Construction/SolutionProjectGenerator_Tests.cs

@@ -83,6 +83,36 @@ public void SolutionProjectIgnoresDuplicateDefaultTargets(string name)
             }
         }
 
+        /// <summary>
+        /// Test that targets in before.{sln}.targets and after.{sln}.targets files are included in the project.
+        /// </summary>
+        [Theory]
+        [InlineData("before.MySln.sln.targets", false)]
+        [InlineData("before.MySln.sln.targets", true)]
+        [InlineData("after.MySln.sln.targets", false)]
+        [InlineData("after.MySln.sln.targets", true)]
+        public void SolutionProjectIncludesBeforeAndAfterTargets(string name, bool convertToSlnx)
+        {
+            using (TestEnvironment testEnvironment = TestEnvironment.Create())
+            {
+                TransientTestFolder folder = testEnvironment.CreateFolder(createFolder: true);
+                string solutionFileContents = "Microsoft Visual Studio Solution File, Format Version 12.00";
+                TransientTestFile sln = testEnvironment.CreateFile(folder, "MySln.sln", solutionFileContents);
+                string solutionPath = convertToSlnx ? SolutionFile_NewParser_Tests.ConvertToSlnx(sln.Path) : sln.Path;
+                testEnvironment.CreateFile(folder, name,
+                      """
+                      <Project>
+                          <Target Name="TestTarget" />
+                      </Project>
+                      """);
+                ProjectInstance[] instances = SolutionProjectGenerator.Generate(SolutionFile.Parse(solutionPath), null, null, _buildEventContext, CreateMockLoggingService());
+                instances.ShouldHaveSingleItem();
+                instances[0].Targets.ShouldContainKey("TestTarget");
+                MockLogger logger = new MockLogger(output);
+                instances[0].Build(targets: null, new List<ILogger> { logger }).ShouldBeTrue();
+            }
+        }
+
         [Fact]
         public void BuildProjectAsTarget()
         {

src/Build/Construction/Solution/SolutionProjectGenerator.cs

@@ -948,15 +948,7 @@ private ProjectInstance CreateTraversalInstance(string wrapperProjectToolsVersio
             // Add our local extensibility points to the project representing the solution
             // Imported at the top: before.mysolution.sln.targets
             // Imported at the bottom: after.mysolution.sln.targets
-            string escapedSolutionFile = EscapingUtilities.Escape(Path.GetFileName(_solutionFile.FullPath));
-            string escapedSolutionDirectory = EscapingUtilities.Escape(_solutionFile.SolutionFileDirectory);
-            string localFile = Path.Combine(escapedSolutionDirectory, "before." + escapedSolutionFile + ".targets");
-            ProjectImportElement importBeforeLocal = traversalProject.CreateImportElement(localFile);
-            importBeforeLocal.Condition = @"exists('" + localFile + "')";
-
-            localFile = Path.Combine(escapedSolutionDirectory, "after." + escapedSolutionFile + ".targets");
-            ProjectImportElement importAfterLocal = traversalProject.CreateImportElement(localFile);
-            importAfterLocal.Condition = @"exists('" + localFile + "')";
+            (ProjectImportElement importBeforeLocal, ProjectImportElement importAfterLocal) = CreateBeforeAndAfterSolutionImports(traversalProject);
 
             // Put locals second so they can override globals if they want
             traversalProject.PrependChild(importBeforeLocal);
@@ -1025,6 +1017,27 @@ private ProjectInstance CreateTraversalInstance(string wrapperProjectToolsVersio
             return traversalInstance;
         }
 
+        private (ProjectImportElement ImportBeforeSln, ProjectImportElement ImportAfterSln) CreateBeforeAndAfterSolutionImports(ProjectRootElement traversalProject)
+        {
+            string escapedSolutionFileName = EscapingUtilities.Escape(Path.GetFileName(_solutionFile.FullPath));
+            if (escapedSolutionFileName.EndsWith(".slnx"))
+            {
+                // We want to load only after.{solutionFileName}.sln.targets for solution files with .slnx extension
+                escapedSolutionFileName = escapedSolutionFileName.Substring(0, escapedSolutionFileName.Length - 1);
+            }
+
+            string escapedSolutionDirectory = EscapingUtilities.Escape(_solutionFile.SolutionFileDirectory);
+            string localFile = Path.Combine(escapedSolutionDirectory, $"before.{escapedSolutionFileName}.targets");
+            ProjectImportElement importBeforeLocal = traversalProject.CreateImportElement(localFile);
+            importBeforeLocal.Condition = $"exists('{localFile}')";
+
+            localFile = Path.Combine(escapedSolutionDirectory, $"after.{escapedSolutionFileName}.targets");
+            ProjectImportElement importAfterLocal = traversalProject.CreateImportElement(localFile);
+            importAfterLocal.Condition = $"exists('{localFile}')";
+
+            return (importBeforeLocal, importAfterLocal);
+        }
+
         private void EmitMetaproject(ProjectRootElement metaproject, string path)
         {
             if (Traits.Instance.EmitSolutionMetaproj)