fix case with ' at the end.

Also guard parsed string from being a Text as literal value

src/AST-Core-Tests/RBParserTest.class.st

@@ -485,6 +485,7 @@ RBParserTest >> testParseFaultyMethod [
 		add: 'method: asd  ^ asd. n'; "invalid expresion after return"
 		add: 'method: asd  ^ {'; "Only Open a literal array"
 		add: 'selector '''; 
+		add: 'selector ''part1''''part2'; "string with escaped ' does not end"
 		add: 'selector #^';
 		add: 'selector ¿';
 		add: ':nl'.
@@ -545,6 +546,40 @@ RBParserTest >> testParseFaultyPragma [
 	self assert: node pragmas first isFaulty
 ]
 
+{ #category : #'tests parsing' }
+RBParserTest >> testParseMethodWhichEndsWithUncompleteStringWithEscapedMarkAtTheEnd [
+	| node strangeMethod body statement message errorNode |
+	strangeMethod := '
+	selector  
+		|temp| 
+		temp := ''this is right'', ''wrong'''''.
+	node := self parseFaultyMethod: strangeMethod.
+
+	self assert: node isMethod.
+	self assert: node isFaulty.
+	self assertEmpty: node arguments.
+
+	body := node body.
+	self assert: body isSequence.
+	self assert: body isFaulty.
+	self assert: (body temporaries includes: (RBVariableNode named: 'temp')).
+
+	statement := body statements first.
+	self assert: statement isFaulty.
+	self assert: statement isAssignment.
+
+	message := statement value.
+	self assert: message isFaulty.
+	self assert: message arguments size equals: 1.
+
+	errorNode := message arguments at: 1.
+	self assert: errorNode isFaulty.
+	self
+		assert: errorNode value
+		equals: 'wrong'''.
+	self assert: errorNode errorMessage equals: 'Unmatched '' in string literal.' translated
+]
+
 { #category : #'tests parsing' }
 RBParserTest >> testParseMethodWithErrorTokenIsWellFormed [
 	| node strangeMethod body statement message errorNode |

src/AST-Core/RBScanner.class.st

@@ -450,10 +450,14 @@ RBScanner >> scanLiteralCharacter [
 { #category : #'private-scanning' }
 RBScanner >> scanLiteralString [
 	| string |
-	[stream atEnd ifTrue: [^ self scanError: 'Unmatched '' in string literal.'].
-	string := stream upTo: $'.
-	stream peekBack = $' ifFalse: [
+	[stream atEnd ifTrue: [
+		self step. "to handle eof"
+		^ self scanError: 'Unmatched '' in string literal.'].
+	string := stream upTo: $'. 
+	stream peekBack = $' ifFalse: [ 
+		"the peek logic here is because #upTo: does not tell if given char was found"
 		buffer nextPutAll: string.
+		self step. "to handle eof"
 		^ self scanError: 'Unmatched '' in string literal.'].
 	
 	self step = $'] whileTrue: [ 
@@ -463,7 +467,13 @@ RBScanner >> scanLiteralString [
 	buffer position = 0 ifFalse: [ 		
 		buffer nextPutAll: string.
 		string := buffer contents].	
-	^RBLiteralToken value: string start: tokenStart stop: self previousStepPosition
+	
+	"It's possible to use a plain Text for parsing.
+	In that case string here could be a Text instance but literal value must be a String"	
+	^RBLiteralToken 
+		value: string asString 
+		start: tokenStart 
+		stop: self previousStepPosition
 ]
 
 { #category : #'private-scanning' }