Fix pharo-project#7898

 - Position should be within the bounds of the source code
 - resolve it to the method's selector

src/Tools-CodeNavigation-Tests/CNSelectorExtractionOnPositionTest.class.st

@@ -71,6 +71,12 @@ CNSelectorExtractionOnPositionTest >> methodWithIfTrueIfFalse [
 		ifFalse: [ self yourself ]
 ]
 
+{ #category : #helpers }
+CNSelectorExtractionOnPositionTest >> methodWithSpacesAtTheEnd [
+	"Please do not remove the leading spaces"
+	^ 1 someMessageFollowedBySpaces  
+]
+
 { #category : #helpers }
 CNSelectorExtractionOnPositionTest >> methodX:a [
 
@@ -167,6 +173,16 @@ CNSelectorExtractionOnPositionTest >> testCaretAfterReturnShouldMatchChildCascad
 	self assert: self selectedSelector equals: cascade messages first selector
 ]
 
+{ #category : #'tests - no selection - return' }
+CNSelectorExtractionOnPositionTest >> testCaretAtEndOfMethodShouldMatchMethodNode [
+
+	self sourceCodeOf: self class >> #methodWithSpacesAtTheEnd.
+
+	self caretAfter: self returnNodeToTest methodNode.
+
+	self assert: self selectedSelector equals: #methodWithSpacesAtTheEnd
+]
+
 { #category : #'tests - no selection - blocks' }
 CNSelectorExtractionOnPositionTest >> testCaretBeforeMessageInBlock [
 

src/Tools-CodeNavigation/CNSelectorExtractor.class.st

@@ -57,7 +57,7 @@ CNSelectorExtractor >> extractSelectorFromAST: ast atPosition: aPosition [
 		ifTrue: [ 0 ]
 		ifFalse: [ -1 ].
 
-	position := aPosition + offset.
+	position := (aPosition + offset) min: ast stop.
 	bestNodeAtPosition := ast bestNodeFor: (position to: position).
 	^ self extractSelectorFromNode: bestNodeAtPosition
 ]