Ignore a false positive nuget-client assets file (#848)

Author: dagood

repos/dir.targets

@@ -392,6 +392,11 @@
       <ProjectDirectories Include="$(ProjectDir)" />
     </ItemGroup>
 
+    <ItemGroup>
+      <!-- This file is a resource tracked by Git, not generated by restore. Ignore false positive. -->
+      <IgnoredProjectAssetsJsonFiles Include="$(SubmoduleDirectory)nuget-client/test/NuGet.Core.Tests/NuGet.Build.Tasks.Pack.Test/compiler/resources/project.assets.json" />
+    </ItemGroup>
+
     <WritePackageUsageData
       RestoredPackageFiles="@(AllRestoredPackageFiles)"
       TarballPrebuiltPackageFiles="@(TarballPrebuiltPackageFiles)"
@@ -401,6 +406,7 @@
       TargetRid="$(TargetRid)"
       ProjectDirectories="@(ProjectDirectories)"
       RootDir="$(ProjectDir)"
+      IgnoredProjectAssetsJsonFiles="@(IgnoredProjectAssetsJsonFiles)"
       DataFile="$(PackageReportDataFile)"
       ProjectAssetsJsonArchiveFile="$(ProjectAssetsJsonArchiveFile)" />
   </Target>

tools-local/tasks/Microsoft.DotNet.SourceBuild.Tasks/UsageReport/WritePackageUsageData.cs

@@ -64,6 +64,12 @@ public class WritePackageUsageData : Task
         [Required]
         public string RootDir { get; set; }
 
+        /// <summary>
+        /// project.assets.json files to ignore, for example, because they are checked-in assets not
+        /// generated during source-build and cause false positives.
+        /// </summary>
+        public string[] IgnoredProjectAssetsJsonFiles { get; set; }
+
         /// <summary>
         /// Output usage data JSON file path.
         /// </summary>
@@ -132,10 +138,11 @@ public override bool Execute()
 
             Log.LogMessage(MessageImportance.Low, "Finding project.assets.json files...");
 
-            string[] assetFiles = Directory.GetFiles(
-                RootDir,
-                "project.assets.json",
-                SearchOption.AllDirectories);
+            string[] assetFiles = Directory
+                .GetFiles(RootDir, "project.assets.json", SearchOption.AllDirectories)
+                .Select(path => path.Substring(RootDir.Length))
+                .Except(IgnoredProjectAssetsJsonFiles.NullAsEmpty())
+                .ToArray();
 
             if (!string.IsNullOrEmpty(ProjectAssetsJsonArchiveFile))
             {
@@ -152,10 +159,9 @@ public override bool Execute()
                 {
                     // Only one entry can be open at a time, so don't do this during the Parallel
                     // ForEach later.
-                    foreach (var file in assetFiles)
+                    foreach (var relativePath in assetFiles)
                     {
-                        string relativePath = file.Substring(RootDir.Length);
-                        using (var stream = File.OpenRead(file))
+                        using (var stream = File.OpenRead(Path.Combine(RootDir, relativePath)))
                         using (Stream entryWriter = projectAssetArchive
                             .CreateEntry(relativePath, CompressionLevel.Optimal)
                             .Open())
@@ -176,7 +182,7 @@ public override bool Execute()
                 {
                     var properties = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
 
-                    using (var file = File.OpenRead(assetFile))
+                    using (var file = File.OpenRead(Path.Combine(RootDir, assetFile)))
                     using (var reader = new StreamReader(file))
                     using (var jsonReader = new JsonTextReader(reader))
                     {
@@ -194,8 +200,7 @@ public override bool Execute()
                         .Where(id => properties.Contains(id.Id + "/" + id.Version.OriginalVersion)))
                     {
                         usages.Add(Usage.Create(
-                            // Store relative path for future report generation.
-                            assetFile.Substring(RootDir.Length),
+                            assetFile,
                             identity,
                             possibleRids));
                     }