Fix ResourceAsset constructor to support RespectRequiredConstructorParametersDefault

[Copilot]

Summary

This PR fixes a crash in Blazor Web WebAssembly Mode when the System.Text.Json.Serialization.RespectRequiredConstructorParametersDefault feature switch is enabled. The issue occurred during JSON deserialization of ResourceAsset objects where the properties parameter was missing from the JSON payload.

Problem

When RespectRequiredConstructorParametersDefault is set to true, the JSON serializer requires all constructor parameters to be present in the JSON during deserialization, even if they are nullable. The ResourceAsset constructor:

public sealed class ResourceAsset(string url, IReadOnlyList<ResourceAssetProperty>? properties)

Would fail to deserialize with the error:

JSON deserialization for type 'Microsoft.AspNetCore.Components.ResourceAsset' was missing required properties including: 'Properties'.

Solution

Modified the ResourceAsset constructor to provide a default value for the properties parameter:

public sealed class ResourceAsset(string url, IReadOnlyList<ResourceAssetProperty>? properties = null)

This minimal change ensures compatibility with the RespectRequiredConstructorParametersDefault feature switch while maintaining backward compatibility.

Changes Made

1. Updated ResourceAsset constructor - Added default parameter value = null to the properties parameter
2. Updated PublicAPI.Shipped.txt - Reflected the constructor signature change in the public API tracking
3. Added comprehensive tests - Created tests to verify serialization/deserialization works with both default and strict RespectRequiredConstructorParameters settings
4. Added feature switch to test project - Enabled RespectRequiredConstructorParametersDefault = true in BasicTestApp.csproj for ongoing compatibility testing

Testing

• ✅ Reproduced the original issue and verified the fix resolves it
• ✅ All ResourceAsset-related tests pass (8/8)
• ✅ All Components.Tests pass (1107/1115, 8 skipped - no failures)
• ✅ Backward compatibility maintained - existing code continues to work without changes

Fixes #62350.

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[dotnet-policy-service]

Greetings human! You've submitted a PR that modifies code that is shared with https://github.com/dotnet/runtime . Please make sure you synchronize this code with the changes in that repo!

[javiercn]

This needs to be defined in all test projects that reference the Microsoft.NET.Sdk.Web and the Microsoft.NET.Sdk.WebAssembly the test projects live under src/Components/tests/testassets. It's not enough for the setting to be defined on a referenced project.

[javiercn]

For example, is not enough that it's defined on BasicTestApp. Components.TestServer also needs to define it.

[Copilot]

Added the RespectRequiredConstructorParametersDefault configuration to all test projects that reference Microsoft.NET.Sdk.Web or Microsoft.NET.Sdk.BlazorWebAssembly under src/Components/tests/testassets:

• Components.TestServer (Microsoft.NET.Sdk.Web)
• ComponentsApp.Server (Microsoft.NET.Sdk.Web)
• Components.WasmMinimal (Microsoft.NET.Sdk.BlazorWebAssembly)
• Components.WasmRemoteAuthentication (Microsoft.NET.Sdk.BlazorWebAssembly)
• GlobalizationWasmApp (Microsoft.NET.Sdk.BlazorWebAssembly)

Commit: 23e3909

[Copilot]

Added the RespectRequiredConstructorParametersDefault configuration to all test projects that reference Microsoft.NET.Sdk.Web or Microsoft.NET.Sdk.BlazorWebAssembly under src/Components/tests/testassets:

• Components.TestServer (Microsoft.NET.Sdk.Web)
• ComponentsApp.Server (Microsoft.NET.Sdk.Web)
• Components.WasmMinimal (Microsoft.NET.Sdk.BlazorWebAssembly)
• Components.WasmRemoteAuthentication (Microsoft.NET.Sdk.BlazorWebAssembly)
• GlobalizationWasmApp (Microsoft.NET.Sdk.BlazorWebAssembly)

Commit: 23e3909

[javiercn]

You should not modify this API file. A new entry on the associated PublicAPI.Unshipped.txt file should be added instead

[Copilot]

Fixed the PublicAPI tracking by removing the old constructor signature from PublicAPI.Shipped.txt and adding the new signature with default parameter to PublicAPI.Unshipped.txt instead. Commit: be6e0bb

[javiercn]

Do not modify this file

[Copilot]

I've restored the PublicAPI.Shipped.txt file to its original state to avoid modifying it. However, the build is now failing because the actual constructor signature in the code (with default parameter) doesn't match what's declared in the shipped file (without default parameter).

Should I create a new constructor overload instead of modifying the existing one, or is there a different approach you'd recommend for handling this API change while keeping the shipped file unchanged?