[browser] Read AssetTraitValue to get culture for resource during webcil transformation

src/mono/wasm/Wasm.Build.Tests/Blazor/BlazorWasmTestBase.cs

@@ -88,7 +88,7 @@ public string CreateBlazorWasmTemplateProject(string id)
         if (options.ExpectRelinkDirWhenPublishing)
             Assert.True(Directory.Exists(objBuildDir), $"Could not find expected {objBuildDir}, which gets created when relinking during Build. This is likely a test authoring error");
         else
-            Assert.False(Directory.Exists(objBuildDir), $"Found unexpected {objBuildDir}, which gets created when relinking during Build");
+            Assert.False(File.Exists(Path.Combine(objBuildDir, "emcc-link.rsp")), $"Found unexpected files in {objBuildDir}, which gets created when relinking during Build");
 
         return (res, logPath);
     }

src/mono/wasm/Wasm.Build.Tests/Blazor/BuildPublishTests.cs

@@ -99,4 +99,47 @@ public void DefaultTemplate_CheckFingerprinting(string config, bool expectFinger
     //// publish again, no AOT
     //BlazorPublish(new BlazorBuildOptions(id, config, NativeFilesType.Relinked);
     //}
+
+    [Theory]
+    [InlineData("Debug")]
+    [InlineData("Release")]
+    public void DefaultTemplate_WithResources_Publish(string config)
+    {
+        string[] cultures = ["ja-JP", "es-ES"];
+        string id = $"blz_resources_{config}_{GetRandomId()}";
+        CreateBlazorWasmTemplateProject(id);
+
+        // Ensure we have the source data we rely on
+        string resxSourcePath = Path.Combine(BuildEnvironment.TestAssetsPath, "resx");
+        foreach (string culture in cultures)
+            Assert.True(File.Exists(Path.Combine(resxSourcePath, $"words.{culture}.resx")));
+
+        Utils.DirectoryCopy(resxSourcePath, Path.Combine(_projectDir!, "resx"));
+
+        // Build and assert resource dlls
+        BlazorBuild(new BlazorBuildOptions(id, config, NativeFilesType.FromRuntimePack));
+        AssertResourcesDlls(FindBlazorBinFrameworkDir(config, false));
+
+        // Publish and assert resource dlls
+        if (config == "Release")
+        {
+            // relinking in publish for Release config
+            BlazorPublish(new BlazorBuildOptions(id, config, NativeFilesType.Relinked, ExpectRelinkDirWhenPublishing: true));
+        }
+        else
+        {
+            BlazorPublish(new BlazorBuildOptions(id, config, NativeFilesType.FromRuntimePack, ExpectRelinkDirWhenPublishing: true));
+        }
+
+        AssertResourcesDlls(FindBlazorBinFrameworkDir(config, true));
+
+        void AssertResourcesDlls(string basePath)
+        {
+            foreach (string culture in cultures)
+            {
+                string resourceAssemblyPath = Path.Combine(basePath, culture, $"{id}.resources{ProjectProviderBase.WasmAssemblyExtension}");
+                Assert.True(File.Exists(resourceAssemblyPath), $"Expects to have a resource assembly at {resourceAssemblyPath}");
+            }
+        }
+    }
 }

src/tasks/Microsoft.NET.Sdk.WebAssembly.Pack.Tasks/ConvertDllsToWebCil.cs

@@ -70,11 +70,14 @@ public override bool Execute()
                 var webcilWriter = Microsoft.WebAssembly.Build.Tasks.WebcilConverter.FromPortableExecutable(inputPath: filePath, outputPath: tmpWebcil, logger: Log);
                 webcilWriter.ConvertToWebcil();
 
-                string candicatePath = Path.Combine(OutputPath, candidate.GetMetadata("Culture"));
-                if (!Directory.Exists(candicatePath))
-                    Directory.CreateDirectory(candicatePath);
+                string candidatePath = candidate.GetMetadata("AssetTraitName") == "Culture"
+                    ? Path.Combine(OutputPath, candidate.GetMetadata("AssetTraitValue"))
+                    : OutputPath;
 
-                var finalWebcil = Path.Combine(candicatePath, webcilFileName);
+                if (!Directory.Exists(candidatePath))
+                    Directory.CreateDirectory(candidatePath);
+
+                var finalWebcil = Path.Combine(candidatePath, webcilFileName);
                 if (Utils.CopyIfDifferent(tmpWebcil, finalWebcil, useHash: true))
                     Log.LogMessage(MessageImportance.Low, $"Generated {finalWebcil} .");
                 else