Add tests

src/HotChocolate/Fusion/src/Core/DependencyInjection/FusionRequestExecutorBuilderExtensions.cs

@@ -301,7 +301,15 @@ public static FusionGatewayBuilder ModifyFusionOptions(
             throw new ArgumentNullException(nameof(modify));
         }
 
-        builder.Services.AddSingleton(modify);
+        builder.CoreBuilder.Configure(
+            c =>
+            {
+                c.OnConfigureSchemaServicesHooks.Add(
+                    (ctx, sc) =>
+                    {
+                        sc.AddSingleton(modify);
+                    });
+            });
 
         return builder;
     }
@@ -547,8 +555,7 @@ internal static ValueTask<ISchema> BuildSchemaAsync(
 
     private static FusionOptions GetFusionOptions(IServiceProvider sp)
     {
-        var appSp = sp.GetApplicationServices();
-        var configures = appSp.GetServices<Action<FusionOptions>>();
+        var configures = sp.GetServices<Action<FusionOptions>>();
         var options = new FusionOptions();
 
         foreach (var configure in configures)

src/HotChocolate/Fusion/test/Core.Tests/OptionsTests.cs

@@ -0,0 +1,73 @@
+using HotChocolate.Fusion.Composition;
+using HotChocolate.Fusion.Composition.Features;
+using HotChocolate.Fusion.Metadata;
+using HotChocolate.Fusion.Shared;
+using HotChocolate.Skimmed.Serialization;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace HotChocolate.Fusion;
+
+public class OptionsTests
+{
+    [Fact]
+    public async Task Options_Are_Scoped_To_Particular_Gateway_Builder()
+    {
+        using var demoProject = await DemoProject.CreateAsync();
+
+        var fusionGraph = await FusionGraphComposer.ComposeAsync(
+            new[]
+            {
+                demoProject.Appointment.ToConfiguration(),
+            },
+            new FusionFeatureCollection(FusionFeatures.NodeField));
+
+        var services = new ServiceCollection()
+            .AddSingleton(demoProject.HttpClientFactory);
+
+        var executor1 = await services
+            .AddFusionGatewayServer("graph1")
+            .ConfigureFromDocument(SchemaFormatter.FormatAsDocument(fusionGraph))
+            .ModifyFusionOptions(options => options.AllowFusionQueryPlan = !options.AllowFusionQueryPlan)
+            .BuildRequestExecutorAsync("graph1");
+
+        var executor2 = await services.AddFusionGatewayServer("graph2")
+            .ConfigureFromDocument(SchemaFormatter.FormatAsDocument(fusionGraph))
+            .BuildRequestExecutorAsync("graph2");
+
+        var options1 = executor1.Services.GetRequiredService<IFusionOptionsAccessor>();
+        var options2 = executor2.Services.GetRequiredService<IFusionOptionsAccessor>();
+        var defaultOptions = new FusionOptions();
+
+        Assert.Equal(options1.AllowFusionQueryPlan, !defaultOptions.AllowFusionQueryPlan);
+        Assert.Equal(options2.AllowFusionQueryPlan, defaultOptions.AllowFusionQueryPlan);
+    }
+
+    [Fact]
+    public async Task Multiple_Option_Modifications_Are_Applied()
+    {
+        using var demoProject = await DemoProject.CreateAsync();
+
+        var fusionGraph = await FusionGraphComposer.ComposeAsync(
+            new[]
+            {
+                demoProject.Appointment.ToConfiguration(),
+            },
+            new FusionFeatureCollection(FusionFeatures.NodeField));
+
+        var services = new ServiceCollection()
+            .AddSingleton(demoProject.HttpClientFactory);
+
+        var executor = await services
+            .AddFusionGatewayServer()
+            .ConfigureFromDocument(SchemaFormatter.FormatAsDocument(fusionGraph))
+            .ModifyFusionOptions(options => options.AllowFusionQueryPlan = !options.AllowFusionQueryPlan)
+            .ModifyFusionOptions(options => options.IncludeFusionDebugInfo = !options.IncludeFusionDebugInfo)
+            .BuildRequestExecutorAsync();
+
+        var options = executor.Services.GetRequiredService<IFusionOptionsAccessor>();
+        var defaultOptions = new FusionOptions();
+
+        Assert.Equal(options.AllowFusionQueryPlan, !defaultOptions.AllowFusionQueryPlan);
+        Assert.Equal(options.IncludeFusionDebugInfo, !defaultOptions.IncludeFusionDebugInfo);
+    }
+}