SupportDotInPropertyNames (#719)

Author: StefH

src/System.Linq.Dynamic.Core/Parser/ExpressionParser.cs

@@ -1357,8 +1357,7 @@ private Expression ParseNew()
                 if (TokenIdentifierIs("as"))
                 {
                     _textParser.NextToken();
-                    propName = GetIdentifier();
-                    _textParser.NextToken();
+                    propName = GetIdentifierAs();
                 }
                 else
                 {
@@ -1648,7 +1647,7 @@ private Expression ParseTypeAccess(Type type, bool getNext)
         return ParseMemberAccess(type, null);
     }
 
-    private bool TryGenerateConversion(Expression sourceExpression, Type destinationType, [NotNullWhen(true) ]out Expression? expression)
+    private bool TryGenerateConversion(Expression sourceExpression, Type destinationType, [NotNullWhen(true)] out Expression? expression)
     {
         Type exprType = sourceExpression.Type;
         if (exprType == destinationType)
@@ -2261,7 +2260,33 @@ private bool TokenIdentifierIs(string id)
     private string GetIdentifier()
     {
         _textParser.ValidateToken(TokenId.Identifier, Res.IdentifierExpected);
-        string id = _textParser.CurrentToken.Text;
+
+        return SanitizeId(_textParser.CurrentToken.Text);
+    }
+
+    private string GetIdentifierAs()
+    {
+        _textParser.ValidateToken(TokenId.Identifier, Res.IdentifierExpected);
+
+        if (!_parsingConfig.SupportDotInPropertyNames)
+        {
+            var id = SanitizeId(_textParser.CurrentToken.Text);
+            _textParser.NextToken();
+            return id;
+        }
+
+        var parts = new List<string>();
+        while (_textParser.CurrentToken.Id is TokenId.Dot or TokenId.Identifier)
+        {
+            parts.Add(_textParser.CurrentToken.Text);
+            _textParser.NextToken();
+        }
+
+        return SanitizeId(string.Concat(parts));
+    }
+
+    private static string SanitizeId(string id)
+    {
         if (id.Length > 1 && id[0] == '@')
         {
             id = id.Substring(1);

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

@@ -220,4 +220,11 @@ public IQueryableAnalyzer QueryableAnalyzer
     /// Default value is <c>true</c>.
     /// </summary>
     public bool PrioritizePropertyOrFieldOverTheType { get; set; } = true;
+
+    /// <summary>
+    /// Support a "." in a property-name. Used in the 'new (a.b as a.b)' syntax.
+    /// 
+    /// Default value is <c>false</c>.
+    /// </summary>
+    public bool SupportDotInPropertyNames { get; set; } = false;
 }

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

@@ -83,6 +83,25 @@ public void CreateGenericComparerTypeForDateTime()
         int lessThan = instance.Compare(b, a);
         lessThan.Should().Be(-1);
     }
+
+    [Fact]
+    public void CreateType_With_PropertyWithDot()
+    {
+        // Arrange
+        var properties = new List<DynamicProperty>
+        {
+            new("x.y", typeof(string))
+        };
+
+        // Act
+        var type = DynamicClassFactory.CreateType(properties);
+
+        // Assert
+        type.GetProperty("x.y").Should().NotBeNull();
+
+        var instance = Activator.CreateInstance(type);
+        instance.Should().NotBeNull();
+    }
 }
 
 public class CustomCaseInsensitiveComparer : IComparer

test/System.Linq.Dynamic.Core.Tests/QueryableTests.Select.cs

@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq.Dynamic.Core.Exceptions;
 using System.Linq.Dynamic.Core.Tests.Helpers.Models;
+using FluentAssertions;
 using Linq.PropertyTranslator.Core;
 using QueryInterceptor.Core;
 using Xunit;
@@ -86,6 +87,23 @@ public void Select_Dynamic_PropertyInBaseClass()
             Assert.Equal(expected.ToArray(), dynamic.ToArray());
         }
 
+        [Fact]
+        public void Select_Dynamic_As_WithDot()
+        {
+            // Assign
+            var qry = User.GenerateSampleModels(1).AsQueryable();
+            var config = new ParsingConfig
+            {
+                SupportDotInPropertyNames = true
+            };
+
+            // Act
+            var result = qry.Select(config, "new (Profile.FirstName as P.FirstName)").ToDynamicArray();
+
+            // Assert
+            result.Should().HaveCount(1);
+        }
+
         [Fact]
         public void Select_Dynamic1()
         {