Fixed accessing dynamic properties by index

src/System.Linq.Dynamic.Core/DynamicClass.cs

@@ -18,7 +18,7 @@ namespace System.Linq.Dynamic.Core;
 /// </summary>
 public abstract class DynamicClass : DynamicObject
 {
-    private Dictionary<string, object?>? _propertiesDictionary = null;
+    private Dictionary<string, object?>? _propertiesDictionary;
 
     private Dictionary<string, object?> Properties
     {
@@ -27,6 +27,7 @@ public abstract class DynamicClass : DynamicObject
             if (_propertiesDictionary == null)
             {
                 _propertiesDictionary = new();
+
                 foreach (PropertyInfo pi in GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance))
                 {
                     int parameters = pi.GetIndexParameters().Length;
@@ -150,7 +151,7 @@ public override bool TryGetMember(GetMemberBinder binder, out object? result)
     /// <returns>
     /// true if the operation is successful; otherwise, false. If this method returns false, the run-time binder of the language determines the behavior. (In most cases, a language-specific run-time exception is thrown.)
     /// </returns>
-    public override bool TrySetMember(SetMemberBinder binder, object value)
+    public override bool TrySetMember(SetMemberBinder binder, object? value)
     {
         string name = binder.Name;
         if (Properties.ContainsKey(name))

test/System.Linq.Dynamic.Core.Tests/DynamicClassTest.cs

@@ -0,0 +1,101 @@
+using System.Collections.Generic;
+using FluentAssertions;
+using Xunit;
+
+namespace System.Linq.Dynamic.Core.Tests;
+
+public class DynamicClassTest
+{
+    [Fact]
+    public void DynamicClass_GetProperties_Should_Work()
+    {
+        // Arrange
+        var range = new List<object>
+        {
+            new { FieldName = "TestFieldName", Value = 3.14159 }
+        };
+
+        // Act
+        var rangeResult = range.AsQueryable().Select("new(FieldName as FieldName)").ToDynamicList();
+        var item = rangeResult.First();
+
+        var call = () => item.GetDynamicMemberNames();
+        call.Should().NotThrow();
+    }
+
+    [Fact]
+    public void DynamicClass_GetPropertyValue_Should_Work()
+    {
+        // Arrange
+        var test = "Test";
+        var range = new List<object>
+        {
+            new { FieldName = test, Value = 3.14159 }
+        };
+
+        // Act
+        var rangeResult = range.AsQueryable().Select("new(FieldName as FieldName)").ToDynamicList();
+        var item = rangeResult.First();
+
+        var value = item.FieldName as string;
+        value.Should().Be(test);
+    }
+
+    [Fact]
+    public void DynamicClass_GettingValue_ByIndex_Should_Work()
+    {
+        // Arrange
+        var test = "Test";
+        var range = new List<object>
+        {
+            new { FieldName = test, Value = 3.14159 }
+        };
+
+        // Act
+        var rangeResult = range.AsQueryable().Select("new(FieldName as FieldName)").ToDynamicList();
+        var item = rangeResult.First();
+
+        var value = item["FieldName"] as string;
+        value.Should().Be(test);
+    }
+
+    [Fact]
+    public void DynamicClass_SettingExistingPropertyValue_ByIndex_Should_Work()
+    {
+        // Arrange
+        var test = "Test";
+        var newTest = "abc";
+        var range = new List<object>
+        {
+            new { FieldName = test, Value = 3.14159 }
+        };
+
+        // Act
+        var rangeResult = range.AsQueryable().Select("new(FieldName as FieldName)").ToDynamicList();
+        var item = rangeResult.First();
+
+        item["FieldName"] = newTest;
+        var value = item["FieldName"] as string;
+        value.Should().Be(newTest);
+    }
+
+    [Fact]
+    public void DynamicClass_SettingNewProperty_ByIndex_Should_Work()
+    {
+        // Arrange
+        var test = "Test";
+        var newTest = "abc";
+        var range = new List<object>
+        {
+            new { FieldName = test, Value = 3.14159 }
+        };
+
+        // Act
+        var rangeResult = range.AsQueryable().Select("new(FieldName as FieldName)").ToDynamicList();
+        var item = rangeResult.First();
+
+        item["X"] = newTest;
+        var value = item["X"] as string;
+        value.Should().Be(newTest);
+    }
+}