[StaticWebAssets] Compress generated html file (#48980)

Author: maraf

src/StaticWebAssetsSdk/Tasks/OverrideHtmlAssetPlaceholders.cs

@@ -98,7 +98,9 @@ public override bool Execute()
                         fileWrites.Add(outputPath);
                     }
 
-                    htmlCandidates.Add(new TaskItem(outputPath, item.CloneCustomMetadata()));
+                    var newItem = new TaskItem(outputPath, item.CloneCustomMetadata());
+                    newItem.RemoveMetadata("OriginalItemSpec");
+                    htmlCandidates.Add(newItem);
                 }
             }
         }

test/Microsoft.NET.Sdk.Razor.Tests/StaticWebAssetsFingerprintingTest.cs

@@ -5,6 +5,7 @@
 
 using Microsoft.AspNetCore.StaticWebAssets.Tasks;
 using System.Text.Json;
+using System.IO.Compression;
 
 namespace Microsoft.NET.Sdk.Razor.Tests;
 
@@ -88,7 +89,7 @@ public void Publish_OverrideHtmlAssetPlaceholders(string testAsset, string scrip
         var indexHtmlOutputPath = Path.Combine(outputPath, "wwwroot", "index.html");
         var endpointsManifestPath = Path.Combine(outputPath, $"{projectName}.staticwebassets.endpoints.json");
 
-        AssertImportMapInHtml(indexHtmlOutputPath, endpointsManifestPath, scriptPath, expectFingerprintOnScript: expectFingerprintOnScript, expectPreloadElement: testAsset == "VanillaWasm");
+        AssertImportMapInHtml(indexHtmlOutputPath, endpointsManifestPath, scriptPath, expectFingerprintOnScript: expectFingerprintOnScript, expectPreloadElement: testAsset == "VanillaWasm", assertHtmlCompressed: true);
     }
 
     private void FingerprintUserJavascriptAssets(bool fingerprintUserJavascriptAssets)
@@ -125,38 +126,81 @@ private void ReplaceStringInIndexHtml(TestAsset testAsset, string sourceValue, s
         }
     }
 
-    private void AssertImportMapInHtml(string indexHtmlPath, string endpointsManifestPath, string scriptPath, bool expectFingerprintOnScript = true, bool expectPreloadElement = false)
+    private void AssertImportMapInHtml(string indexHtmlPath, string endpointsManifestPath, string scriptPath, bool expectFingerprintOnScript = true, bool expectPreloadElement = false, bool assertHtmlCompressed = false)
     {
-        var indexHtmlContent = File.ReadAllText(indexHtmlPath);
-        var endpoints = JsonSerializer.Deserialize<StaticWebAssetEndpointsManifest>(File.ReadAllText(endpointsManifestPath));
 
+        var endpoints = JsonSerializer.Deserialize<StaticWebAssetEndpointsManifest>(File.ReadAllText(endpointsManifestPath));
         var fingerprintedScriptPath = GetFingerprintedPath(scriptPath);
-        if (expectFingerprintOnScript)
+
+        var indexHtmlContent = File.ReadAllText(indexHtmlPath);
+        AssertHtmlContent(indexHtmlContent);
+
+        if (assertHtmlCompressed)
         {
-            Assert.DoesNotContain($"src=\"{scriptPath}\"", indexHtmlContent);
-            Assert.Contains($"src=\"{fingerprintedScriptPath}\"", indexHtmlContent);
+            var indexHtmlGzipContent = DecompressGzipFile(indexHtmlPath + ".gz");
+            AssertHtmlContent(indexHtmlGzipContent);
+
+            var indexHtmlBrotliContent = DecompressBrotliFile(indexHtmlPath + ".br");
+            AssertHtmlContent(indexHtmlBrotliContent);
         }
-        else
+
+        void AssertHtmlContent(string content)
         {
-            Assert.Contains(scriptPath, indexHtmlContent);
+            if (expectFingerprintOnScript)
+            {
+                Assert.DoesNotContain($"src=\"{scriptPath}\"", content);
+                Assert.Contains($"src=\"{fingerprintedScriptPath}\"", content);
+            }
+            else
+            {
+                Assert.Contains(scriptPath, content);
+
+                if (scriptPath != fingerprintedScriptPath)
+                {
+                    Assert.DoesNotContain(fingerprintedScriptPath, content);
+                }
+            }
+
+            Assert.Contains(GetFingerprintedPath("_framework/dotnet.js"), content);
+            Assert.Contains(GetFingerprintedPath("_framework/dotnet.native.js"), content);
+            Assert.Contains(GetFingerprintedPath("_framework/dotnet.runtime.js"), content);
 
-            if (scriptPath != fingerprintedScriptPath)
+            if (expectPreloadElement)
             {
-                Assert.DoesNotContain(fingerprintedScriptPath, indexHtmlContent);
+                Assert.DoesNotContain("<link rel=\"preload\"", content);
+                Assert.Contains($"<link href=\"{fingerprintedScriptPath}\" rel=\"preload\" as=\"script\" fetchpriority=\"high\" crossorigin=\"anonymous\"", content);
             }
         }
 
-        Assert.Contains(GetFingerprintedPath("_framework/dotnet.js"), indexHtmlContent);
-        Assert.Contains(GetFingerprintedPath("_framework/dotnet.native.js"), indexHtmlContent);
-        Assert.Contains(GetFingerprintedPath("_framework/dotnet.runtime.js"), indexHtmlContent);
+        string GetFingerprintedPath(string route)
+            => endpoints.Endpoints.FirstOrDefault(e => e.Route == route && e.Selectors.Length == 0)?.AssetFile ?? throw new Exception($"Missing endpoint for file '{route}' in '{endpointsManifestPath}'");
 
-        if (expectPreloadElement)
+        string DecompressGzipFile(string path)
         {
-            Assert.DoesNotContain("<link rel=\"preload\">", indexHtmlContent);
-            Assert.Contains($"<link href=\"{fingerprintedScriptPath}\" rel=\"preload\" as=\"script\" fetchpriority=\"high\" crossorigin=\"anonymous\"", indexHtmlContent);
+            if (File.Exists(path))
+            {
+                using var fileStream = File.OpenRead(path);
+                using var compressedStream = new GZipStream(fileStream, CompressionMode.Decompress);
+                using var reader = new StreamReader(compressedStream);
+                return reader.ReadToEnd();
+            }
+
+            Assert.Fail($"File '{path}' does not exist.");
+            return null;
         }
 
-        string GetFingerprintedPath(string route)
-            => endpoints.Endpoints.FirstOrDefault(e => e.Route == route && e.Selectors.Length == 0)?.AssetFile ?? throw new Exception($"Missing endpoint for file '{route}' in '{endpointsManifestPath}'");
+        string DecompressBrotliFile(string path)
+        {
+            if (File.Exists(path))
+            {
+                using var fileStream = File.OpenRead(path);
+                using var compressedStream = new BrotliStream(fileStream, CompressionMode.Decompress);
+                using var reader = new StreamReader(compressedStream);
+                return reader.ReadToEnd();
+            }
+
+            Assert.Fail($"File '{path}' does not exist.");
+            return null;
+        }
     }
 }