DynamicExpressionParser.ParseLambda can not parse 'TrimEnd' string method

[Evgentus0]

Here is what to include in your request to make sure we implement a solution as quickly as possible.

1. Description

Trying parse expression which using 'TrimEnd' string method I get an error "No applicable method 'TrimEnd' exists in type 'String''"

2. Exception

• Message : "No applicable method 'TrimEnd' exists in type 'String'"
• StackTrace:
  
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseMemberAccess(Type type, Expression expression)
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseIdentifier()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParsePrimaryStart()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParsePrimary()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseUnary()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseMultiplicative()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseAdditive()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseShiftOperator()
  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.ParseAndOperator()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseOrOperator()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseLambdaOperator()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseNullCoalescingOperator()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.ParseConditionalOperator()
  at System.Linq.Dynamic.Core.Parser.ExpressionParser.Parse(Type resultType, Boolean createParameterCtor)
  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(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)
  at TestEfTranslator.Program.Main(String[] args) in D:\Projects\Examples\TestEfTranslator\TestEfTranslator\Program.cs:line 32

3. Fiddle or Project

To reproduce this issue you can just try to parse next expression:

var expression = DynamicExpressionParser.ParseLambda<string, bool>(new ParsingConfig(), false, "TrimEnd().EndsWith(@0)", "test");
You may even do not use parameters, the main thing is 'TrimEnd()'

[Evgentus0]

It seems that the reason is in MethodFinder.cs, method FindMethod (line 28). The line MemberInfo[] members = t.FindMembers(MemberTypes.Method, flags, Type.FilterNameIgnoreCase, methodName); with method name 'TrimEnd' return only 1 found method, TrimEnd(char[]), so if use TrimEnd() without parameters it will parse in incorrect way.
Try to run something like DynamicExpressionParser.ParseLambda<string, string>(new ParsingConfig(), false, "TrimEnd()"); and you will see expression with strange (null) parameter

[AndriiZ]

Solution:
add
if (args.Length == 0)
{
better = (first.Parameters.Length == 0) && (second.Parameters.Length != 0);
}
to the beginning of bool IsBetterThan(Expression[] args, MethodData first, MethodData second)

Looks like it is lib cant make a dicision if TrimEnd() is better than TrimEnd(char)

[StefH]

Thanks for the fix.

It's merged and I'll add some unit tests.