Fix #8407 sorting with projected navigation orderings

src/HotChocolate/Data/src/Data/Sorting/Expressions/Extensions/QueryableSortContextExtensions.cs

@@ -79,6 +79,11 @@ protected override Expression VisitMethodCall(MethodCallExpression node)
 
         public static bool OrderMethodExists(Expression expression)
         {
+            if (!typeof(IOrderedQueryable).IsAssignableFrom(expression.Type))
+            {
+                return false;
+            }
+
             var visitor = new OrderingMethodFinder();
             visitor.Visit(expression);
             return visitor._orderingMethodFound;

src/HotChocolate/Data/test/Data.EntityFramework.Tests/Issue8407ProbeTests.cs

@@ -0,0 +1,104 @@
+using HotChocolate.Execution;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace HotChocolate.Data;
+
+public class Issue8407ProbeTests
+{
+    [Fact]
+    public async Task Sorting_With_Navigation_OrderBy_In_Projection_Does_Not_Throw()
+    {
+        IServiceProvider services =
+            new ServiceCollection()
+                .AddDbContextPool<Issue8407Context>(
+                    b => b.UseInMemoryDatabase($"Issue8407-{Guid.NewGuid():N}"))
+                .AddGraphQL()
+                .AddSorting()
+                .AddQueryType<Issue8407Query>()
+                .Services
+                .BuildServiceProvider();
+
+        await using (var scope = services.CreateAsyncScope())
+        {
+            await using var db = scope.ServiceProvider.GetRequiredService<Issue8407Context>();
+
+            db.Parents.Add(
+                new Issue8407Parent
+                {
+                    Id = 2,
+                    Children =
+                    [
+                        new Issue8407Child { Id = 21, SomeDate = new DateTime(2025, 1, 2) },
+                        new Issue8407Child { Id = 22, SomeDate = new DateTime(2025, 1, 1) }
+                    ]
+                });
+
+            db.Parents.Add(
+                new Issue8407Parent
+                {
+                    Id = 1,
+                    Children =
+                    [
+                        new Issue8407Child { Id = 11, SomeDate = new DateTime(2025, 1, 3) }
+                    ]
+                });
+
+            await db.SaveChangesAsync();
+        }
+
+        var executor = await services.GetRequiredService<IRequestExecutorProvider>()
+            .GetExecutorAsync();
+
+        var result = await executor.ExecuteAsync(
+            """
+            {
+              parents(order: [{ id: ASC }]) {
+                id
+                children {
+                  id
+                }
+              }
+            }
+            """);
+
+        var operationResult = result.ExpectOperationResult();
+        Assert.Empty(operationResult.Errors ?? []);
+    }
+
+    public sealed class Issue8407Query
+    {
+        [UseSorting]
+        public IQueryable<Issue8407Parent> GetParents(Issue8407Context db) =>
+            db.Parents
+                .Select(p => new Issue8407Parent
+                {
+                    Id = p.Id,
+                    Children = p.Children
+                        .AsQueryable()
+                        .OrderBy(c => c.SomeDate)
+                        .ToList()
+                });
+    }
+
+    public sealed class Issue8407Context(DbContextOptions<Issue8407Context> options) : DbContext(options)
+    {
+        public DbSet<Issue8407Parent> Parents => Set<Issue8407Parent>();
+
+        public DbSet<Issue8407Child> Children => Set<Issue8407Child>();
+    }
+
+    public sealed class Issue8407Parent
+    {
+        public int Id { get; set; }
+
+        public List<Issue8407Child> Children { get; set; } = [];
+    }
+
+    public sealed class Issue8407Child
+    {
+        public int Id { get; set; }
+
+        public DateTime SomeDate { get; set; }
+    }
+}