[Blazor][Fixes #19503] Exclude gzip files from manifest (#19525)

* Exclude gzip files from manifest
* Add a test to validate the service-worker manifest

src/Components/WebAssembly/Build/src/targets/ServiceWorkerAssetsManifest.targets

@@ -39,9 +39,12 @@
   <Target Name="_ComputeServiceWorkerAssetsManifestFileHashes">
 
     <ItemGroup>
-      <ServiceWorkerAssetsManifestItem Include="%(StaticWebAsset.Identity)" Condition="'%(RelativePath)' != '$(ServiceWorkerAssetsManifest)'">
+      <ServiceWorkerAssetsManifestItem
+        Include="%(StaticWebAsset.Identity)"
+        Condition="'%(RelativePath)' != '$(ServiceWorkerAssetsManifest)'">
         <AssetUrl>$([System.String]::Copy('$([System.String]::Copy('%(StaticWebAsset.BasePath)').TrimEnd('/'))/%(StaticWebAsset.RelativePath)').Replace('\','/').TrimStart('/'))</AssetUrl>
       </ServiceWorkerAssetsManifestItem>
+      <ServiceWorkerAssetsManifestItem Remove="@(_CompressedStaticWebAsset->'%(FullPath)')" />
     </ItemGroup>
 
     <GetFileHash Files="@(ServiceWorkerAssetsManifestItem)" Algorithm="SHA256" HashEncoding="base64">

src/Components/WebAssembly/Build/test/BuildIntegrationTests/PwaManifestTests.cs

@@ -0,0 +1,45 @@
+using System.IO;
+using System.Linq;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Components.WebAssembly.Build
+{
+    public class PwaManifestTests
+    {
+        [Fact]
+        public async Task Build_ServiceWorkerAssetsManifest_Works()
+        {
+            // Arrange
+            var expectedExtensions = new[] { ".dll", ".pdb", ".js", ".wasm" };
+            using var project = ProjectDirectory.Create("standalone");
+            var result = await MSBuildProcessManager.DotnetMSBuild(project, args: "/p:ServiceWorkerAssetsManifest=service-worker-assets.js");
+
+            Assert.BuildPassed(result);
+
+            var buildOutputDirectory = project.BuildOutputDirectory;
+
+            Assert.FileExists(result, buildOutputDirectory, "wwwroot", "_framework", "blazor.boot.json");
+            Assert.FileExists(result, buildOutputDirectory, "wwwroot", "_framework", "blazor.webassembly.js");
+            Assert.FileExists(result, buildOutputDirectory, "wwwroot", "_framework", "wasm", "dotnet.wasm");
+            Assert.FileCountEquals(result, 1, Path.Combine(buildOutputDirectory, "wwwroot", "_framework", "wasm"), "dotnet.*.js");
+            Assert.FileExists(result, buildOutputDirectory, "wwwroot", "_framework", "_bin", "standalone.dll");
+            Assert.FileExists(result, buildOutputDirectory, "wwwroot", "_framework", "_bin", "Microsoft.Extensions.Logging.Abstractions.dll"); // Verify dependencies are part of the output.
+
+            var staticWebAssets = Assert.FileExists(result, buildOutputDirectory, "standalone.StaticWebAssets.xml");
+            Assert.FileContains(result, staticWebAssets, Path.Combine("netstandard2.1", "wwwroot"));
+
+            var serviceWorkerAssetsManifest = Assert.FileExists(result, buildOutputDirectory, "wwwroot", "service-worker-assets.js");
+            // Trim prefix 'self.assetsManifest = ' and suffix ';'
+            var manifestContents = File.ReadAllText(serviceWorkerAssetsManifest).TrimEnd()[22..^1];
+
+            var manifestContentsJson = JsonDocument.Parse(manifestContents);
+            Assert.True(manifestContentsJson.RootElement.TryGetProperty("assets", out var assets));
+            Assert.Equal(JsonValueKind.Array, assets.ValueKind);
+
+            var entries = assets.EnumerateArray().Select(e => e.GetProperty("url").GetString()).OrderBy(e => e).ToArray();
+            Assert.All(entries, e => expectedExtensions.Contains(Path.GetExtension(e)));
+        }
+    }
+}