support defining property collection as IEnumerable<> for the new sel…

…ect parser

OData.Client.Abstractions/JsonTemplateHelper.cs

@@ -62,9 +62,11 @@ private static void Initialize(object instance, int remainingLevels)
             {
                 continue;
             }
-            if (prop.PropertyType.IsArray)
+            if (prop.PropertyType.IsArray || (prop.PropertyType.IsGenericType && prop.PropertyType.GetGenericTypeDefinition() == typeof(IEnumerable<>)))
             {
-                var elementType = prop.PropertyType.GetElementType()!;
+                var elementType = prop.PropertyType.IsArray ? 
+                    prop.PropertyType.GetElementType()! :
+                    prop.PropertyType.GetGenericArguments()[0]!;
                 if (IsComplexType(elementType))
                 {
                     var arrayPropInstance = Array.CreateInstance(elementType, 1);

OData.Client.UnitTests/SelectAndExpand/NestedIEnumerable/Target.cs

@@ -0,0 +1,8 @@
+namespace Cblx.OData.Client.Tests.SelectAndExpand.NestedIEnumerable;
+
+public class Target
+{
+    public Guid Id { get; set; }
+
+    public IEnumerable<TargetChild> Children { get; set; }
+}

OData.Client.UnitTests/SelectAndExpand/NestedIEnumerable/TargetChild.cs

@@ -0,0 +1,6 @@
+namespace Cblx.OData.Client.Tests.SelectAndExpand.NestedIEnumerable;
+
+public class TargetChild
+{
+    public Guid Id { get; set; }
+}

OData.Client.UnitTests/SelectAndExpand/NestedIEnumerable/TbSource.cs

@@ -0,0 +1,9 @@
+namespace Cblx.OData.Client.Tests.SelectAndExpand.NestedIEnumerable;
+
+public class TbSource
+{
+    public Guid Id { get; set; }
+
+    public Guid ChildId { get; set; }
+    public TbSourceChild[] Children { get; set; }
+}

OData.Client.UnitTests/SelectAndExpand/NestedIEnumerable/TbSourceChild.cs

@@ -0,0 +1,6 @@
+namespace Cblx.OData.Client.Tests.SelectAndExpand.NestedIEnumerable;
+
+public class TbSourceChild
+{
+    public Guid Id { get; set; }
+}

OData.Client.UnitTests/SelectAndExpand/NestedIEnumerable/Tests.cs

@@ -0,0 +1,20 @@
+namespace Cblx.OData.Client.Tests.SelectAndExpand.NestedIEnumerable;
+
+public class Tests
+{
+    [Fact]
+    public void Old()
+    {
+        string query = "$select=Id&$expand=Children($select=Id)";
+        var parser = new SelectAndExpandParser<TbSource, Target>();
+        parser.ToString().Should().Be(query);
+    }
+
+    [Fact]
+    public void New()
+    {
+        string query = "$select=Id&$expand=Children($select=Id)";
+        var parser = new SelectAndExpandParserV2<TbSource, Target>();
+        parser.ToSelectAndExpand().Query.Should().Be(query);
+    }
+}