1.4.7 Regression -- NullReferenceException from invalid expression instead of ArgumentException

[rbell517]

1. Description

In versions 1.4.6 and previous giving invalid expressions would throw ArgumentException or ArgumentNullException, which we could handle accordingly. Instead now a NullReferenceException is thrown, which is bad practice to throw and bad practice to catch.

2. Exception

Exception message: System.NullReferenceException: Object reference not set to an instance of an object.
Stack trace:
   at System.Linq.Dynamic.Core.Parser.ExpressionHelper.GenerateStaticMethodCall(String methodName, Expression left, Expression right)
   at System.Linq.Dynamic.Core.Parser.ExpressionHelper.GenerateGreaterThanEqual(Expression left, Expression right)
   at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseComparisonOperator()
   at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseLogicalAndOrOperator()
   at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseIn()
   at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseOrOperator()
   at System.Linq.Dynamic.Core.DynamicExpressionParser.ParseLambda(Type delegateType, ParsingConfig parsingConfig, Boolean createParameterCtor, ParameterExpression[] parameters, Type resultType, String expression, Object[] values)
   at System.Linq.Dynamic.Core.DynamicExpressionParser.ParseLambda[T,TResult](ParsingConfig parsingConfig, Boolean createParameterCtor, String expression, Object[] values)

3. Fiddle or Project

https://dotnetfiddle.net/sjyNPf

This example uses a numeric operator on a string type, which is invalid and should throw an ArgumentException, but instead throws a NullReferenceException.

Change the nuget version to 1.4.6 to see the expected exception

4. Any further technical details

Valid expressions do not show any regressions.

[StefH]

#851

[rbell517]

Confirmed the issue is resolved in the new version. Thanks!