Include PDBs in CopyLocal outputs if they exist

Fixes NuGet/Home#2009.

Author: jasonmalinowski

src/Microsoft.NuGet.Build.Tasks.Tests/AssertHelpers.cs

@@ -26,14 +26,28 @@ public static void AssertCountOf(int expectedCount, IEnumerable<ITaskItem> items
         /// </summary>
         public static void PathEndsWith(string expectedPath, string actualPath)
         {
-            if (expectedPath != actualPath)
+            // We could implement this with a simple Assert.True(...EndsWithPath),
+            // but that results in less user-friendly output from the test than a smarter call to
+            // Assert.EndsWith
+            if (!actualPath.EndsWithPath(expectedPath))
             {
-                // This means it must be a subfolder, so we have to prefix with a path component to ensure
-                // we are matching full components
                 Assert.EndsWith("\\" + expectedPath, actualPath);
+
+                // If we get out of sync with this function or EndsWithPath, that Assert might not
+                // fail. In that case, fail the test.
+                throw new Exception("The Assert.EndsWith in the previous line should have failed.");
             }
         }
 
+        /// <summary>
+        /// Returns that the expected path ends with our actual path. "Ends with" in this case is defined by path
+        /// components, so "Directory\File" doesn't end with "ile", to prevent any bugs where path components get mangled.
+        /// </summary>
+        public static bool EndsWithPath(this string path, string suffix)
+        {
+            return path == suffix || path.EndsWith("\\" + suffix);
+        }
+
         public static void AssertNoTargetPaths(IEnumerable<ITaskItem> items)
         {
             foreach (var item in items)

src/Microsoft.NuGet.Build.Tasks.Tests/ReferenceResolutionTests.cs

@@ -218,6 +218,21 @@ public static void IncludingFrameworkReferencesActuallyIncludesFrameworkReferenc
             Assert.Contains("FluentAssertions", packageNames);
         }
 
+        [Fact]
+        public static void CopyLocalContentsIncludePdbsIfAvailable()
+        {
+            var result = NuGetTestHelpers.ResolvePackagesWithJsonFileContents(
+                Default.GetString(Json.Json.FluentAssertionsAndWin10),
+                targetMoniker: "UAP,Version=v10.0",
+                runtimeIdentifier: "win10-x86",
+                includeFrameworkReferences: true);
+
+            Assert.Single(result.CopyLocalItems, r => r.ItemSpec.EndsWithPath("FluentAssertions.dll"));
+            Assert.Single(result.CopyLocalItems, r => r.ItemSpec.EndsWithPath("FluentAssertions.pdb"));
+            Assert.Single(result.CopyLocalItems, r => r.ItemSpec.EndsWithPath("FluentAssertions.Core.dll"));
+            Assert.Single(result.CopyLocalItems, r => r.ItemSpec.EndsWithPath("FluentAssertions.Core.pdb"));
+        }
+
         [Fact]
         public static void FrameworkReferencesAreNotProvidedIfAlreadyProvidedByAnotherPackage()
         {

src/Microsoft.NuGet.Build.Tasks/ResolveNuGetPackageAssets.cs

@@ -262,7 +262,7 @@ private void GetReferences(JObject lockFile)
 
             foreach (var package in GetPackagesFromTarget(lockFile, target))
             {
-                foreach (var referenceItem in CreateItems(package, NuGetAssetTypeCompile))
+                foreach (var referenceItem in CreateItems(package, NuGetAssetTypeCompile, includePdbs: false))
                 {
                     _references.Add(referenceItem);
 
@@ -746,7 +746,7 @@ private string GetTargetMonikerWithOptionalRuntimeIdentifier(ITaskItem preferred
             return needsRuntimeIdentifier ? preferredTargetMoniker.ItemSpec + "/" + RuntimeIdentifier : preferredTargetMoniker.ItemSpec;
         }
 
-        private IEnumerable<ITaskItem> CreateItems(NuGetPackageObject package, string key)
+        private IEnumerable<ITaskItem> CreateItems(NuGetPackageObject package, string key, bool includePdbs = true)
         {
             var values = package.TargetObject[key] as JObject;
             var items = new List<ITaskItem>();
@@ -777,6 +777,22 @@ private IEnumerable<ITaskItem> CreateItems(NuGetPackageObject package, string ke
                 item.SetMetadata(NuGetIsFrameworkReference, "false");
 
                 items.Add(item);
+
+                // If there's a PDB alongside the implementation, we should copy that as well
+                if (includePdbs)
+                {
+                    var pdbFileName = Path.ChangeExtension(item.ItemSpec, ".pdb");
+
+                    if (_fileExists(pdbFileName))
+                    {
+                        var pdbItem = new TaskItem(pdbFileName);
+
+                        // CopyMetadataTo also includes an OriginalItemSpec that will point to our original item, as we want
+                        item.CopyMetadataTo(pdbItem);
+
+                        items.Add(pdbItem);
+                    }
+                }
             }
 
             return items;