Merge pull request #50 from joadan/fix-projection

Fixed Expand Bug

Author: joadan

src/Linq2OData.Core/Expressions/QueryNodeVisitor.cs

@@ -153,8 +153,11 @@ protected override Expression VisitMethodCall(MethodCallExpression node)
                 }
 
                 // Visit the method arguments (typically lambdas)
-                // Skip the first argument if it's the source (for extension methods)
-                var startIndex = (node.Object == null && node.Arguments.Count > 0 && node.Arguments[0] == sourceMember) ? 1 : 0;
+                // Skip the first argument if it's the source (for extension methods).
+                // Also skip if it's a MethodCallExpression that was already visited in the early
+                // else block above (e.g. the inner Select in .Select(...).ToList()).
+                var startIndex = (node.Object == null && node.Arguments.Count > 0 &&
+                    (node.Arguments[0] == sourceMember || node.Arguments[0] is MethodCallExpression)) ? 1 : 0;
                 for (int i = startIndex; i < node.Arguments.Count; i++)
                 {
                     Visit(node.Arguments[i]);

test/Linq2OData.TestClients/Program.cs

@@ -1,5 +1,5 @@
 //using DemoClientV4.ODataDemo;
-using DemoClientV4.ODataDemo;
+//using DemoClientV4.ODataDemo;
 using Linq2OData.Core.Metadata;
 using Linq2OData.Generator.Models;
 
@@ -17,14 +17,15 @@ static async Task Main(string[] args)
         {
             Console.WriteLine("Here we go!");
 
-            //await GenerateDemoClientV2Async();
+            // await GenerateDemoClientV2Async();
             //await GenerateDemoClientV4Async();
             //await GenerateTripPinClientAsync();
 
             //GenerateLargeClientAsync();
 
-           //     await TestTripPinAsync();
-            await TestV4ClientAsync();
+            //     await TestTripPinAsync();
+            //await TestV4ClientAsync();
+            await TestV2ClientAsync();
         }
 
         private static async Task TestTripPinAsync()
@@ -90,11 +91,17 @@ private static async Task TestV2ClientAsync()
 
             var kalle = clientV2.Services;
 
-            var queryResult = await clientV2
-               .Query<DemoClientV2.ODataDemo.Product>()
-               .Filter(e => e.ID != 1)
-               .Expand(expand => expand.Category!.Products)
-               .ExecuteAsync();
+            //var queryResult = await clientV2
+            //   .Query<DemoClientV2.ODataDemo.Product>()
+            //   .Filter(e => e.ID != 1)
+            //   .Select(e => e.Select(e => new DemoClientV2.ODataDemo.Product { Name = e.Name, Price = e.Price, Supplier = new DemoClientV2.ODataDemo.Supplier { Name = e.Name } }))
+            //   .ExecuteAsync();
+
+            var query = clientV2
+            .Query<DemoClientV2.ODataDemo.Supplier>()
+            .Select(e => e.Select(e => new DemoClientV2.ODataDemo.Supplier { Name = e.Name, Products = e.Products!.Select(p => new DemoClientV2.ODataDemo.Product { Name = p.Name }).ToList() }));
+         
+            var queryResult = await query.ExecuteAsync();
 
 
             var r = queryResult;
@@ -112,7 +119,7 @@ private static async Task TestV4ClientAsync()
             var clientV4 = new DemoClientV4.ODataDemoClientV4(httpClient);
 
             var queryResult = await clientV4
-            .Get<Product>(e => e.ID = 4)
+            .Get<DemoClientV4.ODataDemo.Product>(e => e.ID = 4)
             .Expand(e => e.Categories)
             .Expand(e => e.Supplier)
             .ExecuteAsync();
@@ -185,7 +192,7 @@ private static async Task GenerateTripPinClientAsync()
 
         private static void GenerateLargeClientAsync()
         {
-           
+
             var metadata = File.ReadAllText("Metadata/LargeMetadata.xml");
 
 
@@ -212,8 +219,8 @@ private static void GenerateLargeClientAsync()
 
             var files = generator.GenerateClient(Path.Combine(projectDirectory, "LargeClientV4"));
 
-          //  var files = generator.GenerateClient();
-          
+            //  var files = generator.GenerateClient();
+
         }
 
 

test/Linq2OData.Tests/ExpandTests.cs

@@ -781,6 +781,51 @@ public void Expand_MultiplePropertiesFromSameNestedEntity_V4_GroupsCorrectly()
 
     #endregion
 
+    #region Collection Select with ToList
+
+    [Fact]
+    public void Select_WithToListOnNavigationProperty_V2_DoesNotDuplicateExpand()
+    {
+        // Regression: when a nav-property collection is projected via .Select(...).ToList(),
+        // the inner Select MethodCallExpression was visited twice in VisitMethodCall —
+        // once by the early "visit chained source" path and once by the normal arguments loop.
+        // The second visit placed the nav-property as a child of itself, producing
+        // $expand=OrderItems/OrderItems instead of $expand=OrderItems.
+        var visitor = new QueryNodeVisitor();
+        Expression<Func<List<TestOrder>, List<TestOrder>>> expression = list =>
+            list.Select(o => new TestOrder
+            {
+                ID = o.ID,
+                OrderItems = o.OrderItems!.Select(i => new TestOrderItem { Quantity = i.Quantity }).ToList()
+            }).ToList();
+
+        var node = visitor.Parse(expression);
+        var result = node.GetSelectExpand(ODataVersion.V2);
+
+        Assert.Equal("ID,OrderItems", result.select);
+        Assert.Equal("OrderItems", result.expand);
+    }
+
+    [Fact]
+    public void Select_WithToListOnNavigationProperty_V4_DoesNotDuplicateExpand()
+    {
+        var visitor = new QueryNodeVisitor();
+        Expression<Func<List<TestOrder>, List<TestOrder>>> expression = list =>
+            list.Select(o => new TestOrder
+            {
+                ID = o.ID,
+                OrderItems = o.OrderItems!.Select(i => new TestOrderItem { Quantity = i.Quantity }).ToList()
+            }).ToList();
+
+        var node = visitor.Parse(expression);
+        var result = node.GetSelectExpand(ODataVersion.V4);
+
+        Assert.Equal("ID", result.select);
+        Assert.Equal("OrderItems($select=Quantity)", result.expand);
+    }
+
+    #endregion
+
     #region OData Version Comparison Tests
 
     [Fact]