added symbol check when checking for identifier (#728)

* added symbol check

* added test case for preference

* simplified code for type prioritization

Author: abbasc52

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

@@ -931,10 +931,20 @@ private Expression ParseIdentifier()
 
         var isValidKeyWord = _keywordsHelper.TryGetValue(_textParser.CurrentToken.Text, out var value);
 
-        var extraCondition = !_parsingConfig.PrioritizePropertyOrFieldOverTheType ||
-                             (_parsingConfig.PrioritizePropertyOrFieldOverTheType && !(value is Type && _it != null && FindPropertyOrField(_it.Type, _textParser.CurrentToken.Text, false) != null));
+        
+        bool shouldPrioritizeType = true;
+        
+        if (_parsingConfig.PrioritizePropertyOrFieldOverTheType && value is Type)
+        {
+            bool isPropertyOrField = _it != null && FindPropertyOrField(_it.Type, _textParser.CurrentToken.Text, false) != null;
+            bool hasSymbol = _symbols.ContainsKey(_textParser.CurrentToken.Text);
+            if (isPropertyOrField || hasSymbol)
+            {
+                shouldPrioritizeType = false;
+            }
+        }
 
-        if (isValidKeyWord && extraCondition)
+        if (isValidKeyWord && shouldPrioritizeType)
         {
             if (value is Type typeValue)
             {

test/System.Linq.Dynamic.Core.Tests/Parser/ExpressionParserTests.cs

@@ -331,12 +331,14 @@ public void Parse_NullableShouldReturnNullable(string expression, object resultT
     [InlineData("Company.Equals(null, null)", "Equals(null, null)")]
     [InlineData("MainCompany.Name", "company.MainCompany.Name")]
     [InlineData("Name", "company.Name")]
+    [InlineData("company.Name","company.Name")]
     [InlineData("DateTime", "company.DateTime")]
     public void Parse_When_PrioritizePropertyOrFieldOverTheType_IsTrue(string expression, string result)
     {
         // Arrange
         var config = new ParsingConfig
         {
+            IsCaseSensitive = true,
             CustomTypeProvider = _dynamicTypeProviderMock.Object
         };
         ParameterExpression[] parameters = { ParameterExpressionHelper.CreateParameterExpression(typeof(Company), "company") };