Refactor method calls and add new tests (#851)

Modified `#if` directive in `NotNullWhenAttribute.cs` to include `NETSTANDARD2_0` and remove `NETSTANDARD1_3_OR_GREATER`. Updated `GenerateStaticMethodCall` in `ExpressionHelper.cs` to use `TryGetStaticMethod` instead of `GetStaticMethod`, throwing an `ArgumentException` if the method is not found. Replaced `GetStaticMethod` with `TryGetStaticMethod` in `ExpressionHelper.cs`. Added `MyView` class with nullable `Properties` dictionary to `ExpressionParserTests.cs`. Added `Parse_InvalidExpressionShouldThrowArgumentException` test to verify `ArgumentException` is thrown for invalid expressions.

Author: StefH

src/System.Linq.Dynamic.Core/Compatibility/CodeAnalysis/NotNullWhenAttribute.cs

@@ -22,7 +22,7 @@
 // SOFTWARE.
 #endregion
 
-#if NETSTANDARD1_3_OR_GREATER || NET35 || NET40 || NET45 || NET452 || NET46 || NETCOREAPP2_1 || UAP10_0
+#if NETSTANDARD1_3 || NETSTANDARD2_0 || NET35 || NET40 || NET45 || NET452 || NET46 || NETCOREAPP2_1 || UAP10_0
 
 // ReSharper disable once CheckNamespace
 namespace System.Diagnostics.CodeAnalysis;

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

@@ -477,7 +477,11 @@ private void TryConvertTypes(ref Expression left, ref Expression right)
 
     private static Expression GenerateStaticMethodCall(string methodName, Expression left, Expression right)
     {
-        var methodInfo = GetStaticMethod(methodName, left, right);
+        if (!TryGetStaticMethod(methodName, left, right, out var methodInfo))
+        {
+            throw new ArgumentException($"Method '{methodName}' not found on type '{left.Type}' or '{right.Type}'");
+        }
+
         var parameters = methodInfo.GetParameters();
         var parameterTypeLeft = parameters[0].ParameterType;
         var parameterTypeRight = parameters[1].ParameterType;
@@ -495,15 +499,10 @@ private static Expression GenerateStaticMethodCall(string methodName, Expression
         return Expression.Call(null, methodInfo, [left, right]);
     }
 
-    private static MethodInfo GetStaticMethod(string methodName, Expression left, Expression right)
+    private static bool TryGetStaticMethod(string methodName, Expression left, Expression right, [NotNullWhen(true)] out MethodInfo? methodInfo)
     {
-        var methodInfo = left.Type.GetMethod(methodName, [left.Type, right.Type]);
-        if (methodInfo == null)
-        {
-            methodInfo = right.Type.GetMethod(methodName, [left.Type, right.Type])!;
-        }
-
-        return methodInfo;
+        methodInfo = left.Type.GetMethod(methodName, [left.Type, right.Type]) ?? right.Type.GetMethod(methodName, [left.Type, right.Type]);
+        return methodInfo != null;
     }
 
     private static Expression? GetMethodCallExpression(MethodCallExpression methodCallExpression)

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

@@ -27,6 +27,10 @@ public enum ExampleFlags
         D = 8,
     };
 
+    public class MyView
+    {
+        public Dictionary<string, string>? Properties { get; set; }
+    }
 
     public ExpressionParserTests()
     {
@@ -421,8 +425,18 @@ public void Parse_StringConcat(string expression, string result)
 
         // Act
         var parsedExpression = parser.Parse(typeof(string)).ToString();
-        
+
         // Assert
         parsedExpression.Should().Be(result);
     }
+
+    [Fact]
+    public void Parse_InvalidExpressionShouldThrowArgumentException()
+    {
+        // Arrange & Act
+        Action act = () => DynamicExpressionParser.ParseLambda<MyView, bool>(ParsingConfig.Default, false, "Properties[\"foo\"] > 2", Array.Empty<object>());
+
+        // Assert
+        act.Should().Throw<ArgumentException>().WithMessage("Method 'Compare' not found on type 'System.String' or 'System.Int32'");
+    }
 }