JSS TP4 ComponentName workaround

CustomPlaceholderTransformer.cs

using Sitecore.JavaScriptServices.ViewEngine.LayoutService.Serialization;
using Sitecore.LayoutService.ItemRendering;
using RenderedJsonRendering = Sitecore.JavaScriptServices.ViewEngine.ItemRendering.RenderedJsonRendering;

namespace MyNamespace.JavaScriptServices.ViewEngine.LayoutService.Serialization
{
    public class CustomPlaceholderTransformer : PlaceholderTransformer
    {
        public override object TransformPlaceholderElement(RenderedPlaceholderElement element)
        {
            var transformedElement = (dynamic)base.TransformPlaceholderElement(element);

            // This check is a bit redundant because the base method does the same check, but the type cast is necessary.
            if (!(element is RenderedJsonRendering renderingElement))
            {
                return element;
            }

            // This is the important part, changing the erroneous base `componentName` property to the value 
            // provided in the `Component Name` field.
            transformedElement.componentName = renderingElement.ComponentName;
            return transformedElement;
        }
    }
}

RegisterDependencies.cs

// Make sure this assembly is registered with the container _after_ Sitecore.JavaScriptServices.ViewEngine.dll
// e.g.
/*
 <services>
   ...
   <configurator type="Sitecore.JavaScriptServices.ViewEngine.RegisterDependencies, Sitecore.JavaScriptServices.ViewEngine" />
   <configurator type="MyNamespace.JavaScriptServices.ViewEngine.RegisterDependencies, MyNamespace.JavaScriptServices.ViewEngine" />
   ...
 </services>
*/

using Microsoft.Extensions.DependencyInjection;
using Sitecore.DependencyInjection;
using Sitecore.JavaScriptServices.ViewEngine.LayoutService;
using MyNamespace.JavaScriptServices.ViewEngine.LayoutService.Serialization;

namespace MyNamespace.JavaScriptServices.ViewEngine
{
  public class RegisterDependencies : IServicesConfigurator
  {
    public void Configure(IServiceCollection serviceCollection)
    {
      serviceCollection.AddTransient<IPlaceholderTransformer, CustomPlaceholderTransformer>();
    }
  }
}