From dfa74eaa3eeda96cb76031fc99dff11c4cca2c3e Mon Sep 17 00:00:00 2001
From: Viktor Hofer <viktor.hofer@microsoft.com>
Date: Tue, 15 Feb 2022 17:30:39 +0100
Subject: [PATCH 1/3] Traversal: Keep GetTargetPath in sync with Build

https://github.com/microsoft/MSBuildSdks/commit/1c02e77c5d96c50b803e348b6c3444b578d3dee0 I made the GetTargetPath target for traversal projects return nothing. This is actually wrong as msbuild projects are expected to return the same data in the Build and the GetTargetPath target.
If those two targets aren't in sync, a behavior difference is observable when a traversal project is P2Pd and the dependent project reads from the `CollectedBuildOutput` (which is returned by the `ResolveProjectReferences` target). If the `BuildProjectReferences=true` flag is passed in, the output in the ResolveP2P is currently empty vs. not empty during a normal build without the flag set.
---
 src/Traversal/Sdk/Sdk.targets | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/src/Traversal/Sdk/Sdk.targets b/src/Traversal/Sdk/Sdk.targets
index a1e28d18..844a8376 100644
--- a/src/Traversal/Sdk/Sdk.targets
+++ b/src/Traversal/Sdk/Sdk.targets
@@ -95,6 +95,10 @@
 
     <PublishDependsOn Condition="'$(NoBuild)' == 'true'">
     </PublishDependsOn>
+    
+    <GetTargetPathDependsOn>
+      ResolveP2PReferences;
+    </GetTargetPathDependsOn>
   </PropertyGroup>
 
   <ItemGroup Condition=" '$(TraversalTranslateProjectFileItems)' != 'false' ">
@@ -236,10 +240,23 @@
              ContinueOnError="$([MSBuild]::ValueOrDefault('$(PublishContinueOnError)', '$(ContinueOnError)'))" />
   </Target>
   
-  <!--
-    Traversal projects do not build an assembly so dependent projects shouldn't get a path to the target.  Override the GetTargetPath to do nothing.
-  -->
-  <Target Name="GetTargetPath" />
+  <Target Name="GetTargetPath"
+          DependsOnTargets="$(GetTargetPathDependsOn)"
+          Returns="@(CollectedBuildOutput)">
+    <MSBuild Projects="@(ProjectReference)"
+             Condition="'%(ProjectReference.Build)' != 'false'"
+             Targets="GetTargetPath"
+             BuildInParallel="$([MSBuild]::ValueOrDefault('%(ProjectReference.BuildInParallel)', '$(BuildInParallel)'))"
+             SkipNonexistentProjects="$(SkipNonexistentProjects)"
+             SkipNonexistentTargets="$(SkipNonexistentTargets)"
+             StopOnFirstFailure="$(StopOnFirstFailure)"
+             Properties="%(ProjectReference.SetConfiguration); %(ProjectReference.SetPlatform); %(ProjectReference.SetTargetFramework)"
+             ContinueOnError="$(ContinueOnError)">
+      <Output TaskParameter="TargetOutputs" ItemName="CollectedBuildOutput" />
+    </MSBuild>
+  </Target>
+
+  <Target Name="GetTargetPathWithTargetPlatformMoniker" />
 
   <!--
     Traversal projects do not build anything and should not check for invalid configuration/platform.

From 82a608a193b144938fbe181985eeec7d8a9e3572 Mon Sep 17 00:00:00 2001
From: Viktor Hofer <viktor.hofer@microsoft.com>
Date: Tue, 15 Feb 2022 20:59:07 +0100
Subject: [PATCH 2/3] Update Sdk.targets

---
 src/Traversal/Sdk/Sdk.targets | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/Traversal/Sdk/Sdk.targets b/src/Traversal/Sdk/Sdk.targets
index 844a8376..3ad75345 100644
--- a/src/Traversal/Sdk/Sdk.targets
+++ b/src/Traversal/Sdk/Sdk.targets
@@ -96,9 +96,7 @@
     <PublishDependsOn Condition="'$(NoBuild)' == 'true'">
     </PublishDependsOn>
     
-    <GetTargetPathDependsOn>
-      ResolveP2PReferences;
-    </GetTargetPathDependsOn>
+    <GetTargetPathDependsOn></GetTargetPathDependsOn>
   </PropertyGroup>
 
   <ItemGroup Condition=" '$(TraversalTranslateProjectFileItems)' != 'false' ">

From a62106d7c6b8ff53dfde03144fca209f808f1dbf Mon Sep 17 00:00:00 2001
From: Jeff Kluge <jeffkl@microsoft.com>
Date: Thu, 17 Feb 2022 09:17:52 -0800
Subject: [PATCH 3/3] Add unit tests

---
 Packages.props                                |  2 +-
 .../CustomProjectCreatorTemplates.cs          | 15 +++++
 src/Traversal.UnitTests/TraversalTests.cs     | 65 ++++++-------------
 3 files changed, 37 insertions(+), 45 deletions(-)

diff --git a/Packages.props b/Packages.props
index 7137d4df..c3ebaa54 100644
--- a/Packages.props
+++ b/Packages.props
@@ -8,7 +8,7 @@
     <PackageReference Update="Microsoft.Build.Utilities.Core" Version="$(MicrosoftBuildPackageVersion)" />
     <PackageReference Update="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Update="Microsoft.Win32.Registry" Version="4.7.0" />
-    <PackageReference Update="MSBuild.ProjectCreation" Version="7.0.4-preview" />
+    <PackageReference Update="MSBuild.ProjectCreation" Version="7.0.7-preview" />
     <PackageReference Update="Shouldly" Version="4.0.3" />
     <PackageReference Update="xunit" Version="2.4.1" />
     <PackageReference Update="xunit.runner.visualstudio" Version="2.4.3" />
diff --git a/src/Traversal.UnitTests/CustomProjectCreatorTemplates.cs b/src/Traversal.UnitTests/CustomProjectCreatorTemplates.cs
index baf626f8..161d9c40 100644
--- a/src/Traversal.UnitTests/CustomProjectCreatorTemplates.cs
+++ b/src/Traversal.UnitTests/CustomProjectCreatorTemplates.cs
@@ -13,6 +13,21 @@ public static class CustomProjectCreatorTemplates
     {
         private static readonly string ThisAssemblyDirectory = Path.GetDirectoryName(typeof(CustomProjectCreatorTemplates).Assembly.Location);
 
+        public static ProjectCreator ProjectWithBuildOutput(
+            this ProjectCreatorTemplates templates,
+            string target,
+            ProjectCollection projectCollection = null,
+            Action<ProjectCreator> customAction = null)
+        {
+            return ProjectCreator.Templates.SdkCsproj(
+                    sdk: String.Empty,
+                    projectCreator: customAction,
+                    projectCollection: projectCollection)
+                .Target(target, returns: "@(CollectedBuildOutput)")
+                    .TargetItemInclude("CollectedBuildOutput", Path.Combine("bin", "$(MSBuildThisFileName).dll"))
+                .Target("Clean");
+        }
+
         public static ProjectCreator TraversalProject(
             this ProjectCreatorTemplates templates,
             string[] projectReferences = null,
diff --git a/src/Traversal.UnitTests/TraversalTests.cs b/src/Traversal.UnitTests/TraversalTests.cs
index 533bf9fc..df922c88 100644
--- a/src/Traversal.UnitTests/TraversalTests.cs
+++ b/src/Traversal.UnitTests/TraversalTests.cs
@@ -19,57 +19,34 @@ namespace Microsoft.Build.Traversal.UnitTests
     public class TraversalTests : MSBuildSdkTestBase
     {
         [Theory]
-        [InlineData(null)]
         [InlineData("Build")]
-        [InlineData("Rebuild")]
+        [InlineData("GetTargetPath")]
         public void CollectsProjectReferenceBuildTargetOutputs(string target)
         {
-            string[] projects = new[]
-            {
-                GetSkeletonCSProjWithTargetOutputs(@"A\A"),
-                GetSkeletonCSProjWithTargetOutputs(@"B\B"),
-            }.Select(i => i.FullPath).ToArray();
-
-            var subTraversalProject = ProjectCreator
-                .Templates
-                .TraversalProject(projects, path: GetTempFile(@"dirs\dirs.proj"))
-                .Save();
-
-            ProjectCreator
-                .Create(path: GetTempFile("root.proj"))
-                .Target("BuildTraversalProject")
-                .Task(
-                    "MSBuild",
-                    parameters: new Dictionary<string, string>
-                    {
-                        ["Projects"] = subTraversalProject.FullPath,
-                        ["Targets"] = "Restore",
-                        ["Properties"] = $"MSBuildRestoreSessionId={Guid.NewGuid():N}",
-                    })
-                .Task(
-                    "MSBuild",
-                    parameters: new Dictionary<string, string>
+            ProjectCreator traversalProject = ProjectCreator.Templates.TraversalProject(
+                    projectReferences: new string[]
                     {
-                        ["Projects"] = subTraversalProject.FullPath,
-                        ["Targets"] = target,
+                        ProjectCreator.Templates.ProjectWithBuildOutput(target)
+                            .Save(GetTempFile(Path.Combine("A", "A.csproj"))),
+                        ProjectCreator.Templates.ProjectWithBuildOutput(target)
+                            .Save(GetTempFile(Path.Combine("B", "B.csproj"))),
                     })
-                .TaskOutputItem("TargetOutputs", "CollectedOutputs")
-                .TaskMessage("%(CollectedOutputs.Identity)", MessageImportance.High)
-                .Save()
-                .TryBuild("BuildTraversalProject", out bool _, out BuildOutput buildOutput);
+                .Property("SkipResolvePackageAssets", bool.TrueString)
+                .Target("ResolvePackageAssets")
+                .Save(GetTempFile("dirs.proj"))
+                .TryBuild(target, out bool result, out BuildOutput buildOutput, out IDictionary<string, TargetResult> targetOutputs);
 
-            buildOutput.Messages.High.ShouldContain("A.dll", buildOutput.GetConsoleLog());
-            buildOutput.Messages.High.ShouldContain("B.dll", buildOutput.GetConsoleLog());
+            result.ShouldBeTrue(buildOutput.GetConsoleLog());
 
-            ProjectCreator GetSkeletonCSProjWithTargetOutputs(string projectName)
-            {
-                return ProjectCreator.Templates.SdkCsproj(path: GetTempFile($"{projectName}.csproj"), sdk: string.Empty)
-                                    .Target("Build", returns: "@(TestReturnItem)")
-                                    .TargetItemGroup()
-                                    .TargetItemInclude("TestReturnItem", "$(MSBuildThisFileName).dll")
-                                    .Target("Clean")
-                                    .Save();
-            }
+            targetOutputs.ShouldContainKey(target, buildOutput.GetConsoleLog());
+
+            targetOutputs[target].Items.Select(i => i.ItemSpec).ShouldBe(
+                new[]
+                {
+                    Path.Combine("bin", "A.dll"),
+                    Path.Combine("bin", "B.dll"),
+                },
+                buildOutput.GetConsoleLog());
         }
 
         [Fact]