Fix panic in printer utilities when processing cross-file positions

Co-authored-by: RyanCavanaugh <[email protected]>

Author: Copilot

internal/printer/utilities.go

@@ -358,7 +358,13 @@ func getStartPositionOfRange(r core.TextRange, sourceFile *ast.SourceFile, inclu
 	if ast.PositionIsSynthesized(r.Pos()) {
 		return -1
 	}
-	return scanner.SkipTriviaEx(sourceFile.Text(), r.Pos(), &scanner.SkipTriviaOptions{StopAtComments: includeComments})
+	text := sourceFile.Text()
+	pos := r.Pos()
+	// Bounds check: if position is beyond text length, it's likely from a different file
+	if pos >= len(text) {
+		return pos // Return the original position without trying to skip trivia
+	}
+	return scanner.SkipTriviaEx(text, pos, &scanner.SkipTriviaOptions{StopAtComments: includeComments})
 }
 
 func positionsAreOnSameLine(pos1 int, pos2 int, sourceFile *ast.SourceFile) bool {
@@ -388,19 +394,31 @@ func getLinesBetweenRangeEndAndRangeStart(range1 core.TextRange, range2 core.Tex
 }
 
 func getLinesBetweenPositionAndPrecedingNonWhitespaceCharacter(pos int, stopPos int, sourceFile *ast.SourceFile, includeComments bool) int {
-	startPos := scanner.SkipTriviaEx(sourceFile.Text(), pos, &scanner.SkipTriviaOptions{StopAtComments: includeComments})
+	text := sourceFile.Text()
+	if pos >= len(text) {
+		return 0 // Can't determine line differences for out-of-bounds positions
+	}
+	startPos := scanner.SkipTriviaEx(text, pos, &scanner.SkipTriviaOptions{StopAtComments: includeComments})
 	prevPos := getPreviousNonWhitespacePosition(startPos, stopPos, sourceFile)
 	return getLinesBetweenPositions(sourceFile, core.IfElse(prevPos >= 0, prevPos, stopPos), startPos)
 }
 
 func getLinesBetweenPositionAndNextNonWhitespaceCharacter(pos int, stopPos int, sourceFile *ast.SourceFile, includeComments bool) int {
-	nextPos := scanner.SkipTriviaEx(sourceFile.Text(), pos, &scanner.SkipTriviaOptions{StopAtComments: includeComments})
+	text := sourceFile.Text()
+	if pos >= len(text) {
+		return 0 // Can't determine line differences for out-of-bounds positions
+	}
+	nextPos := scanner.SkipTriviaEx(text, pos, &scanner.SkipTriviaOptions{StopAtComments: includeComments})
 	return getLinesBetweenPositions(sourceFile, pos, core.IfElse(stopPos < nextPos, stopPos, nextPos))
 }
 
 func getPreviousNonWhitespacePosition(pos int, stopPos int, sourceFile *ast.SourceFile) int {
+	text := sourceFile.Text()
 	for ; pos >= stopPos; pos-- {
-		if !stringutil.IsWhiteSpaceLike(rune(sourceFile.Text()[pos])) {
+		if pos >= len(text) {
+			continue // Skip out-of-bounds positions
+		}
+		if !stringutil.IsWhiteSpaceLike(rune(text[pos])) {
 			return pos
 		}
 	}

internal/scanner/issue1092_test.go

@@ -2094,9 +2094,6 @@ func SkipTriviaEx(text string, pos int, options *SkipTriviaOptions) int {
 	}
 
 	textLen := len(text)
-	if pos >= textLen {
-		return pos
-	}
 	canConsumeStar := false
 	// Keep in sync with couldStartTrivia
 	for {
@@ -2330,15 +2327,7 @@ func GetLineStarts(sourceFile ast.SourceFileLike) []core.TextPos {
 func GetLineAndCharacterOfPosition(sourceFile ast.SourceFileLike, pos int) (line int, character int) {
 	lineMap := GetLineStarts(sourceFile)
 	line = ComputeLineOfPosition(lineMap, pos)
-	textLen := len(sourceFile.Text())
-	startPos := int(lineMap[line])
-	if pos > textLen {
-		pos = textLen
-	}
-	if startPos > textLen {
-		startPos = textLen
-	}
-	character = utf8.RuneCountInString(sourceFile.Text()[startPos:pos])
+	character = utf8.RuneCountInString(sourceFile.Text()[lineMap[line]:pos])
 	return
 }