Incorrect parse of the method argument when it starts with delimiter #57

Author: VitaliyMF

src/NReco.LambdaParser.Tests/LambdaParserTests.cs

@@ -1,6 +1,6 @@
 using System;
-using System.Collections.Generic;
 using System.Collections;
+using System.Collections.Generic;
 using System.Diagnostics;
 using Xunit;
 
@@ -79,6 +79,13 @@ public void Eval() {
 
 			Assert.Equal(true, lambdaParser.Eval(" (1+testObj.IntProp)==2 ? testObj.FldTrue : false ", varContext));
 
+			Assert.Equal("3", lambdaParser.Eval("toString( (1+2) )", varContext) as string);
+			Assert.Equal("3", lambdaParser.Eval("(1+2).ToString()", varContext) as string);
+
+			Assert.Throws<LambdaParserException>(() => lambdaParser.Eval("toString( (1+2)", varContext));
+			Assert.Throws<LambdaParserException>(() => lambdaParser.Eval("toString( (1+2), )", varContext));
+			Assert.Throws<LambdaParserException>(() => lambdaParser.Eval("toString( 1 ", varContext));
+
 			Assert.Equal("ab2_3", lambdaParser.Eval(" \"a\"+testObj.Format(\"b{0}_{1}\", 2, \"3\".ToString() ).ToString() ", varContext));
 
 			Assert.Equal(true, lambdaParser.Eval(" testObj.Hash[\"a\"] == \"1\"", varContext));
@@ -104,6 +111,9 @@ public void Eval() {
 			Assert.Equal(3, lambdaParser.Eval(" new { {\"a\", 1}, {\"b\", 2}, {\"c\", 3} }.Count ", varContext));
 			Assert.Equal(3, lambdaParser.Eval(" { \"a\": 1, \"b\": 2, \"c\": 3 }.Count ", varContext));
 			Assert.Equal(0, lambdaParser.Eval(" { }.Count ", varContext));
+
+			Assert.Equal("1", lambdaParser.Eval("toString( { \"a\": 1 }.Count ) ", varContext) as string);
+			
 			Assert.Throws<LambdaParserException>(() => lambdaParser.Eval("{ \"a\": 1, \"b\": 2, }", varContext));
 			Assert.Throws<LambdaParserException>(() => lambdaParser.Eval("{ \"a\"  }", varContext));
 			Assert.Throws<LambdaParserException>(() => lambdaParser.Eval("{ \"a\":  }", varContext));

src/NReco.LambdaParser/Linq/LambdaParser.cs

@@ -610,17 +610,20 @@ protected int ReadCallArguments(string expr, int start, string endLexem, List<Ex
 			do {
 				var lexem = ReadLexem(expr, end);
 				if (lexem.Type == LexemType.Delimiter) {
-					if (lexem.GetValue() == endLexem) {
-						return lexem.End;
-					} else if (lexem.GetValue() == ",") {
+					if (lexem.GetValue()==endLexem)
+						return lexem.End; // no more arguments
+
+					if (lexem.GetValue()==",") {
 						if (args.Count == 0) {
-							throw new LambdaParserException(expr, lexem.Start, "Value missed");
+							throw new LambdaParserException(expr, lexem.Start, "Value expected before ','");
 						}
 						end = lexem.End;
-					} else {
-						throw new LambdaParserException(expr, lexem.Start, String.Format("Expected '{0}' or ','", endLexem));
-					}
+					} 
 				}
+				if (lexem.Type==LexemType.Stop) {
+					throw new LambdaParserException(expr, lexem.Start, String.Format("Expected '{0}' or ','", endLexem));
+				}
+
 				// read parameter
 				var paramExpr = ParseConditional(expr, end, vars);
 				args.Add(ExprConvertToObjectIfNeeded(paramExpr.Expr));