fix: support passing assigned render mode via parameter builder

Author: egil

src/bunit.core/ComponentParameterCollectionBuilder.cs

@@ -78,7 +78,7 @@ public ComponentParameterCollectionBuilder<TComponent> Add<TChildComponent>(Expr
 	/// <param name="parameterSelector">A lambda function that selects the parameter.</param>
 	/// <param name="markup">The markup string to pass to the <see cref="RenderFragment"/>.</param>
 	/// <returns>This <see cref="ComponentParameterCollectionBuilder{TComponent}"/>.</returns>
-	public ComponentParameterCollectionBuilder<TComponent> Add(Expression<Func<TComponent, RenderFragment?>> parameterSelector, [StringSyntax("Html")]string markup)
+	public ComponentParameterCollectionBuilder<TComponent> Add(Expression<Func<TComponent, RenderFragment?>> parameterSelector, [StringSyntax("Html")] string markup)
 		=> Add(parameterSelector, markup.ToMarkupRenderFragment());
 
 	/// <summary>
@@ -266,7 +266,7 @@ public ComponentParameterCollectionBuilder<TComponent> AddChildContent(RenderFra
 	/// </summary>
 	/// <param name="markup">The markup string to pass the ChildContent parameter wrapped in a <see cref="RenderFragment"/>.</param>
 	/// <returns>This <see cref="ComponentParameterCollectionBuilder{TComponent}"/>.</returns>
-	public ComponentParameterCollectionBuilder<TComponent> AddChildContent([StringSyntax("Html")]string markup)
+	public ComponentParameterCollectionBuilder<TComponent> AddChildContent([StringSyntax("Html")] string markup)
 		=> AddChildContent(markup.ToMarkupRenderFragment());
 
 	/// <summary>
@@ -344,11 +344,11 @@ public ComponentParameterCollectionBuilder<TComponent> Bind<TValue>(
 		Action<TValue> changedAction,
 		Expression<Func<TValue>>? valueExpression = null)
 	{
-		#if !NET8_0_OR_GREATER
+#if !NET8_0_OR_GREATER
 		var (parameterName, _, isCascading) = GetParameterInfo(parameterSelector);
-		#else
+#else
 		var (parameterName, _, isCascading) = GetParameterInfo(parameterSelector, initialValue);
-		#endif
+#endif
 
 		if (isCascading)
 			throw new ArgumentException("Using Bind with a cascading parameter is not allowed.", parameterName);
@@ -397,6 +397,13 @@ static string TrimEnd(string source, string value)
 			: source;
 	}
 
+#if NET9_0_OR_GREATER
+	public ComponentParameterCollectionBuilder<TComponent> SetAssignedRenderMode(IComponentRenderMode? renderMode)
+	{
+		return this;
+	}
+#endif
+
 	/// <summary>
 	/// Try to add a <paramref name="value"/> for a parameter with the <paramref name="name"/>, if
 	/// <typeparamref name="TComponent"/> has a property with that name, AND that property has a <see cref="ParameterAttribute"/>
@@ -454,14 +461,14 @@ Expression<Func<TComponent, TValue>> parameterSelector
 			: propInfoCandidate;
 
 		var paramAttr = propertyInfo?.GetCustomAttribute<ParameterAttribute>(inherit: true);
-	#if !NET8_0_OR_GREATER
+#if !NET8_0_OR_GREATER
 		var cascadingParamAttr = propertyInfo?.GetCustomAttribute<CascadingParameterAttribute>(inherit: true);
 
 		if (propertyInfo is null || (paramAttr is null && cascadingParamAttr is null))
 			throw new ArgumentException($"The parameter selector '{parameterSelector}' does not resolve to a public property on the component '{typeof(TComponent)}' with a [Parameter] or [CascadingParameter] attribute.", nameof(parameterSelector));
 
 		return (propertyInfo.Name, CascadingValueName: cascadingParamAttr?.Name, IsCascading: cascadingParamAttr is not null);
-	#else
+#else
 		var cascadingParamAttrBase = propertyInfo?.GetCustomAttribute<CascadingParameterAttributeBase>(inherit: true);
 
 		if (propertyInfo is null || (paramAttr is null && cascadingParamAttrBase is null))
@@ -494,7 +501,7 @@ static ArgumentException CreateErrorMessageForSupplyFromQuery(
 			                              NavigationManager.NavigateTo(uri);
 			                              """);
 		}
-	#endif
+#endif
 	}
 
 	private static bool HasChildContentParameter()

tests/bunit.core.tests/Rendering/RenderModeTests.razor

@@ -125,6 +125,36 @@
             </text>);
 	}
 
+    [Fact(DisplayName = "SetAssignedRenderMode on root component")]
+    public void Test011()
+    {
+        var cut = RenderComponent<ComponentThatPrintsAssignedRenderMode>(ps => ps.SetAssignedRenderMode(RenderMode.InteractiveServer));
+        cut.MarkupMatches(@<p>Assigned Render Mode: InteractiveServerRenderMode</p>);
+    }
+
+    [Fact(DisplayName = "SetAssignedRenderMode on parent component cascades to children")]
+    public void Test012()
+    {
+        var cut = RenderComponent<ComponentWithChildContent>(ps => ps
+            .SetAssignedRenderMode(RenderMode.InteractiveWebAssembly)
+            .AddChildContent<ComponentThatPrintsAssignedRenderMode>());
+
+        cut.MarkupMatches(@<p>Assigned Render Mode: InteractiveWebAssemblyRenderMode</p>);
+    }
+
+    [Fact(DisplayName = "SetAssignedRenderMode child components")]
+    public void Test013()
+    {
+        var cut = RenderComponent<ComponentWithChildContent>(ps => ps
+            .AddChildContent<ComponentThatPrintsAssignedRenderMode>(pps => pps.SetAssignedRenderMode(RenderMode.InteractiveServer))
+            .AddChildContent<ComponentThatPrintsAssignedRenderMode>(pps => pps.SetAssignedRenderMode(RenderMode.InteractiveWebAssembly)));
+
+        cut.MarkupMatches(
+            @<text>
+                <p>Assigned Render Mode: InteractiveServerRenderMode</p>
+                <p>Assigned Render Mode: InteractiveWebAssemblyRenderMode</p>
+            </text>);
+    }
 
     [Fact(DisplayName = "Different assigned RenderMode between child and parent throws")]
 	public void Test020()