Fix cached validation failure in RequiredOrder

src/EfOrderBy/RequiredOrder.cs

@@ -12,8 +12,6 @@ public static void Validate(DbContext context)
             return;
         }
 
-        validated.Add(contextType);
-
         // Check if this DbContext requires ordering for all entities (opt-in feature)
         var requireOrdering = context.GetService<IDbContextOptions>()
             .FindExtension<OrderRequiredExtension>()
@@ -23,6 +21,10 @@ public static void Validate(DbContext context)
         {
             ValidateAllEntitiesHaveOrdering(context.Model);
         }
+
+        // Marked only after validation succeeds, so a failed validation keeps throwing
+        // instead of silently passing on every subsequent query
+        validated.Add(contextType);
     }
 
     static void ValidateAllEntitiesHaveOrdering(IModel model)

src/Tests/RequireOrderingTests.cs

@@ -54,6 +54,23 @@ public async Task RequireOrderingForAllEntities_ThrowsWhenEntityMissingOrdering(
         Assert.That(ex.Message, Does.Contain("do not have ordering configured"));
     }
 
+    [Test]
+    public async Task RequireOrderingForAllEntities_ThrowsOnEveryQueryNotJustTheFirst()
+    {
+        await using var database = await sqlInstanceWithMissing.Build();
+        await using var context = database.NewDbContext();
+
+        Assert.ThrowsAsync<Exception>(() => context.EntitiesWithoutDefaultOrder.ToListAsync());
+
+        // Validation is cached per DbContext type. A failed validation must not be cached,
+        // otherwise the error disappears after the first query and later queries silently
+        // return unordered results
+        var exception = Assert.ThrowsAsync<Exception>(() => context.EntitiesWithoutDefaultOrder.ToListAsync());
+
+        Assert.That(exception!.Message, Does.Contain("EntityWithoutDefaultOrder"));
+        Assert.That(exception.Message, Does.Contain("do not have ordering configured"));
+    }
+
     [Test]
     public async Task RequireOrderingForAllEntities_SucceedsWhenAllEntitiesHaveOrdering()
     {