[release/10.0] [browser] Expect fingerprint on dotnet.js for preloading (#120746)

Backport of #120694 to release/10.0

In dotnet/sdk#50949 we changed the identity of
StaticWebAsset to contain fingerprint (dotnet.native.wasm ->
dotnet.native.FP.wasm). This PR accommodates this when checking for
dotnet.native.wasm asset from build.

The SDK change didn't flown to the runtime yet, and so Wasm.Build.Tests
won't test it yet.

Fixes dotnet/aspnetcore#64011

/cc @maraf

## Customer Impact

- [ ] Customer reported
- [x] Found internally

[[Select one or both of the boxes. Describe how this issue impacts
customers, citing the expected and actual behaviors and scope of the
issue. If customer-reported, provide the issue
number.]](dotnet/aspnetcore#64011)

## Regression

- [x] Yes
- [ ] No

Introduced in dotnet/sdk#50949 which added a
fingerprint to the msbuild item identity

## Testing

Manual and automated tests.

## Risk

Low. The change are very scoped to target and items used only by
preloading.

**IMPORTANT**: If this backport is for a servicing release, please
verify that:

- The PR target branch is `release/X.0-staging`, not `release/X.0`.

## Package authoring no longer needed in .NET 9

**IMPORTANT**: Starting with .NET 9, you no longer need to edit a NuGet
package's csproj to enable building and bump the version.
Keep in mind that we still need package authoring in .NET 8 and older
versions.

---------

Co-authored-by: Marek Fišera <mara@neptuo.com>
Co-authored-by: Larry Ewing <lewing@microsoft.com>

Author: 3 people

eng/Versions.props

@@ -163,7 +163,7 @@
     <MicrosoftExtensionsLoggingVersion>3.1.7</MicrosoftExtensionsLoggingVersion>
     <MicrosoftSymbolStoreVersion>1.0.406601</MicrosoftSymbolStoreVersion>
     <!-- sdk version, for testing workloads -->
-    <SdkVersionForWorkloadTesting>$(MicrosoftDotNetApiCompatTaskVersion)</SdkVersionForWorkloadTesting>
+    <SdkVersionForWorkloadTesting>10.0.100-rc.2.25501.103</SdkVersionForWorkloadTesting>
     <EmsdkPackageVersion>10.0.0-preview.7.25359.101</EmsdkPackageVersion>
     <NodePackageVersion>$(runtimewinx64MicrosoftNETCoreRuntimeWasmNodeTransportPackageVersion)</NodePackageVersion>
     <!-- The package path for python in src/mono/mono.proj needs to be updated if this changes-->

src/mono/nuget/Microsoft.NET.Sdk.WebAssembly.Pack/build/Microsoft.NET.Sdk.WebAssembly.Browser.targets

@@ -514,8 +514,13 @@ Copyright (c) .NET Foundation. All rights reserved.
   </Target>
 
   <Target Name="_AddWasmPreloadBuildProperties" DependsOnTargets="_WasmConfigurePreload;_AddWasmStaticWebAssets" BeforeTargets="GenerateStaticWebAssetsManifest" Condition="'$(_WasmPreloadAssets)' == 'true'">
+    <PropertyGroup>
+      <_WasmBootConfigFileNameWithoutExtension>$([System.IO.Path]::GetFileNameWithoutExtension('$(_WasmBootConfigFileName)'))</_WasmBootConfigFileNameWithoutExtension>
+      <_WasmBootConfigFileExtension>$([System.IO.Path]::GetExtension('$(_WasmBootConfigFileName)'))</_WasmBootConfigFileExtension>
+    </PropertyGroup>
     <ItemGroup>
-      <_WasmPreloadBuildScriptAsset Include="@(StaticWebAsset)" Condition="'%(AssetKind)' != 'Publish' and '%(FileName)%(Extension)' == '$(_WasmBootConfigFileName)'" />
+      <_WasmPreloadBuildScriptAsset Include="@(StaticWebAsset)" Condition="'$(_WasmFingerprintAssets)' == 'true' and '$(_WasmFingerprintBootConfig)' == 'true' and '%(AssetKind)' != 'Publish' and '%(FileName)%(Extension)' == '$(_WasmBootConfigFileNameWithoutExtension).%(Fingerprint)$(_WasmBootConfigFileExtension)'" />
+      <_WasmPreloadBuildScriptAsset Include="@(StaticWebAsset)" Condition="('$(_WasmFingerprintAssets)' != 'true' or '$(_WasmFingerprintBootConfig)' != 'true') and '%(AssetKind)' != 'Publish' and '%(FileName)%(Extension)' == '$(_WasmBootConfigFileName)'" />
     </ItemGroup>
 
     <FilterStaticWebAssetEndpoints

src/mono/wasm/Wasm.Build.Tests/PreloadingTests.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.IO;
 using System.Linq;
 using Xunit;
@@ -18,22 +19,26 @@ public PreloadingTests(ITestOutputHelper output, SharedBuildPerTestClassFixture
     }
 
     [Theory]
-    [InlineData(false, false)]
-    [InlineData(false, true)]
-    [InlineData(true, false)]
-    [InlineData(true, true)]
-    public void PreloadAssets(bool isPublish, bool fingerprintDotnetJs)
+    [InlineData(false, false, false)]
+    [InlineData(false, false, true)]
+    [InlineData(false, true, false)]
+    [InlineData(false, true, true)]
+    [InlineData(true, false, false)]
+    [InlineData(true, false, true)]
+    [InlineData(true, true, false)]
+    [InlineData(true, true, true)]
+    public void PreloadAssets(bool isPublish, bool fingerprintDotnetJs, bool preloadAssets)
     {
         Configuration config = Configuration.Debug;
         ProjectInfo info = CopyTestAsset(config, aot: false, TestAsset.WasmBasicTestApp, "PreloadAssets");
 
-        string extraMSBuildArgs = $"-p:WasmFingerprintDotnetJs={fingerprintDotnetJs}";
+        string extraMSBuildArgs = $"-p:WasmFingerprintDotnetJs={fingerprintDotnetJs.ToString().ToLower()} -p:WasmPreloadAssets={preloadAssets.ToString().ToLower()}";
         if (isPublish)
             PublishProject(info, config, new PublishOptions(ExtraMSBuildArgs: extraMSBuildArgs), wasmFingerprintDotnetJs: fingerprintDotnetJs);
         else
             BuildProject(info, config, new BuildOptions(ExtraMSBuildArgs: extraMSBuildArgs), wasmFingerprintDotnetJs: fingerprintDotnetJs);
 
-        string? indexHtmlPath = null;
+        string? indexHtmlPath;
         if (isPublish)
         {
             indexHtmlPath = Path.Combine(
@@ -51,16 +56,37 @@ public void PreloadAssets(bool isPublish, bool fingerprintDotnetJs)
         Assert.True(File.Exists(indexHtmlPath));
         string indexHtmlContent = File.ReadAllText(indexHtmlPath);
 
-        if (fingerprintDotnetJs)
+        Assert.Equal(preloadAssets ? 1 : 0, CountOccurrences(indexHtmlContent, "rel=\"preload\""));
+        if (preloadAssets)
         {
-            // Expect to find fingerprinted preload
-            Assert.Contains("<link href=\"_framework/dotnet", indexHtmlContent);
-            Assert.DoesNotContain("<link href=\"_framework/dotnet.js\"", indexHtmlContent);
+            if (fingerprintDotnetJs)
+            {
+                // Expect to find fingerprinted preload
+                Assert.Contains("<link href=\"_framework/dotnet", indexHtmlContent);
+                Assert.DoesNotContain("<link href=\"_framework/dotnet.js\"", indexHtmlContent);
+            }
+            else
+            {
+                // Expect to find non-fingerprinted preload
+                Assert.Contains("<link href=\"_framework/dotnet.js\"", indexHtmlContent);
+            }
         }
-        else
+    }
+
+    public static int CountOccurrences(string source, string substring)
+    {
+        if (string.IsNullOrEmpty(source) || string.IsNullOrEmpty(substring))
+            return 0;
+
+        int count = 0;
+        int index = 0;
+
+        while ((index = source.IndexOf(substring, index, StringComparison.Ordinal)) != -1)
         {
-            // Expect to find non-fingerprinted preload
-            Assert.Contains("<link href=\"_framework/dotnet.js\"", indexHtmlContent);
+            count++;
+            index += substring.Length;
         }
+
+        return count;
     }
 }