fix: internal ctors on Stub not working with Activator.CreateInstance

Author: egil

src/bunit.web/ComponentFactories/StubComponentFactory.cs

@@ -22,9 +22,7 @@ public bool CanCreate(Type componentType)
 	public IComponent Create(Type componentType)
 	{
 		var typeToCreate = StubType.MakeGenericType(componentType);
-		return replacementContent is not null
-			? (IComponent)Activator.CreateInstance(typeToCreate, new object?[] { replacementContent })!
-			: (IComponent)Activator.CreateInstance(typeToCreate, Array.Empty<object?>())!;
+		return (IComponent)Activator.CreateInstance(typeToCreate, new object?[] { replacementContent })!;
 	}
 }
 #endif

src/bunit.web/TestDoubles/Components/Stub{TComponent}.cs

@@ -16,20 +16,20 @@ public sealed class Stub<TComponent> : ComponentDoubleBase<TComponent>
 	/// <summary>
 	/// Initializes a new instance of the <see cref="Stub{TComponent}"/> class.
 	/// </summary>
-	internal Stub() { }
+	public Stub() { }
 
 	/// <summary>
 	/// Initializes a new instance of the <see cref="Stub{TComponent}"/> class
 	/// that uses the provided <paramref name="replacement"/> when rendering.
 	/// </summary>
 	/// <param name="replacement">The replacement template to use when rendering.</param>
-	internal Stub(object replacement)
+	public Stub(object? replacement)
 	{
 		if (replacement is RenderFragment<CapturedParameterView<TComponent>> replacementTemplate)
 			this.replacementTemplate = replacementTemplate;
 		else if (replacement is RenderFragment replacementFragment)
 			this.replacementFragment = replacementFragment;
-		else
+		else if (replacement is not null)
 			throw new ArgumentException($"The type of replacement is not supported. Replacement type = {replacement.GetType()}", nameof(replacement));
 	}