[Blazor] Fix manifest integrity computation (#22771)

* [Blazor] Fix manifest integrity computation

* Add a couple of tests to validate incrementalism

2 files changed, 74 insertions, 1 deletions

diff --git a/src/Components/WebAssembly/Build/src/targets/ServiceWorkerAssetsManifest.targets b/src/Components/WebAssembly/Build/src/targets/ServiceWorkerAssetsManifest.targets
index 3a72b4e62a..c17edf60e0 100644
--- a/src/Components/WebAssembly/Build/src/targets/ServiceWorkerAssetsManifest.targets
+++ b/src/Components/WebAssembly/Build/src/targets/ServiceWorkerAssetsManifest.targets
@@ -163,7 +163,7 @@
 
     <WriteLinesToFile
       File="$(_CombinedHashIntermediatePath)"
-      Lines="@(_ServiceWorkerAssetsManifestItemWithHash->'%(FileHash)')"
+      Lines="@(_ServiceWorkerAssetsManifestItemWithHash->'%(Integrity)')"
       WriteOnlyWhenDifferent="true"
       Overwrite="true" />
 
diff --git a/src/Components/WebAssembly/Build/test/BuildIntegrationTests/PwaManifestTests.cs b/src/Components/WebAssembly/Build/test/BuildIntegrationTests/PwaManifestTests.cs
index a268e8f8ea..464d361e70 100644
--- a/src/Components/WebAssembly/Build/test/BuildIntegrationTests/PwaManifestTests.cs
+++ b/src/Components/WebAssembly/Build/test/BuildIntegrationTests/PwaManifestTests.cs
@@ -1,6 +1,7 @@
 using System.IO;
 using System.Linq;
 using System.Text.Json;
+using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using Xunit;
 
@@ -41,5 +42,77 @@ namespace Microsoft.AspNetCore.Components.WebAssembly.Build
             var entries = assets.EnumerateArray().Select(e => e.GetProperty("url").GetString()).OrderBy(e => e).ToArray();
             Assert.All(entries, e => expectedExtensions.Contains(Path.GetExtension(e)));
         }
+
+        [Fact]
+        public async Task Publish_UpdatesServiceWorkerVersionHash_WhenSourcesChange()
+        {
+            // Arrange
+            using var project = ProjectDirectory.Create("standalone", additionalProjects: new[] { "razorclasslibrary" });
+            var result = await MSBuildProcessManager.DotnetMSBuild(project, "Publish", args: "/bl:initial.binlog /p:ServiceWorkerAssetsManifest=service-worker-assets.js");
+
+            Assert.BuildPassed(result);
+
+            var publishOutputDirectory = project.PublishOutputDirectory;
+
+            var serviceWorkerFile = Assert.FileExists(result, publishOutputDirectory, "wwwroot", "serviceworkers", "my-service-worker.js");
+            var version = File.ReadAllLines(serviceWorkerFile).Last();
+            var match = Regex.Match(version, "\\/\\* Manifest version: (.{8}) \\*\\/");
+            Assert.True(match.Success);
+            Assert.Equal(2, match.Groups.Count);
+            Assert.NotNull(match.Groups[1].Value);
+            var capture = match.Groups[1].Value;
+
+            // Act
+            var cssFile = Path.Combine(project.DirectoryPath, "LinkToWebRoot", "css", "app.css");
+            File.WriteAllText(cssFile, ".updated { }");
+
+            // Assert
+            var updatedResult = await MSBuildProcessManager.DotnetMSBuild(project, "Publish", args: "/bl:updated.binlog /p:ServiceWorkerAssetsManifest=service-worker-assets.js");
+
+            Assert.BuildPassed(result);
+
+            var updatedVersion = File.ReadAllLines(serviceWorkerFile).Last();
+            var updatedMatch = Regex.Match(updatedVersion, "\\/\\* Manifest version: (.{8}) \\*\\/");
+            Assert.True(updatedMatch.Success);
+            Assert.Equal(2, updatedMatch.Groups.Count);
+            Assert.NotNull(updatedMatch.Groups[1].Value);
+            var updatedCapture = updatedMatch.Groups[1].Value;
+
+            Assert.NotEqual(capture, updatedCapture);
+        }
+
+        [Fact]
+        public async Task Publish_DeterministicAcrossBuilds_WhenNoSourcesChange()
+        {
+            // Arrange
+            using var project = ProjectDirectory.Create("standalone", additionalProjects: new[] { "razorclasslibrary" });
+            var result = await MSBuildProcessManager.DotnetMSBuild(project, "Publish", args: "/bl:initial.binlog /p:ServiceWorkerAssetsManifest=service-worker-assets.js");
+
+            Assert.BuildPassed(result);
+
+            var publishOutputDirectory = project.PublishOutputDirectory;
+
+            var serviceWorkerFile = Assert.FileExists(result, publishOutputDirectory, "wwwroot", "serviceworkers", "my-service-worker.js");
+            var version = File.ReadAllLines(serviceWorkerFile).Last();
+            var match = Regex.Match(version, "\\/\\* Manifest version: (.{8}) \\*\\/");
+            Assert.True(match.Success);
+            Assert.Equal(2, match.Groups.Count);
+            Assert.NotNull(match.Groups[1].Value);
+            var capture = match.Groups[1].Value;
+
+            // Act && Assert
+            var updatedResult = await MSBuildProcessManager.DotnetMSBuild(project, "Publish", args: "/bl:updated.binlog /p:ServiceWorkerAssetsManifest=service-worker-assets.js");
+
+            Assert.BuildPassed(result);
+
+            var updatedVersion = File.ReadAllLines(serviceWorkerFile).Last();
+            var updatedMatch = Regex.Match(updatedVersion, "\\/\\* Manifest version: (.{8}) \\*\\/");
+            Assert.True(updatedMatch.Success);
+            Assert.Equal(2, updatedMatch.Groups.Count);
+            Assert.NotNull(updatedMatch.Groups[1].Value);
+            var updatedCapture = updatedMatch.Groups[1].Value;
+
+            Assert.Equal(capture, updatedCapture);
+        }
     }
 }