Introduce GetECMALineOfPosition to avoid unused rune counting (#2065)

jakebailey · web-flow · commit b17a2c697bc4 · 2025-11-12T01:39:21.000Z
diff --git a/internal/checker/grammarchecks.go b/internal/checker/grammarchecks.go
@@ -798,8 +798,8 @@ func (c *Checker) checkGrammarArrowFunction(node *ast.Node, file *ast.SourceFile
 	}
 
 	equalsGreaterThanToken := arrowFunc.EqualsGreaterThanToken
-	startLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, equalsGreaterThanToken.Pos())
-	endLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, equalsGreaterThanToken.End())
+	startLine := scanner.GetECMALineOfPosition(file, equalsGreaterThanToken.Pos())
+	endLine := scanner.GetECMALineOfPosition(file, equalsGreaterThanToken.End())
 	return startLine != endLine && c.grammarErrorOnNode(equalsGreaterThanToken, diagnostics.Line_terminator_not_permitted_before_arrow)
 }
 
diff --git a/internal/compiler/program.go b/internal/compiler/program.go
@@ -1082,7 +1082,7 @@ func (p *Program) getDiagnosticsWithPrecedingDirectives(sourceFile *ast.SourceFi
 	// Build map of directives by line number
 	directivesByLine := make(map[int]ast.CommentDirective)
 	for _, directive := range sourceFile.CommentDirectives {
-		line, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, directive.Loc.Pos())
+		line := scanner.GetECMALineOfPosition(sourceFile, directive.Loc.Pos())
 		directivesByLine[line] = directive
 	}
 	lineStarts := scanner.GetECMALineStarts(sourceFile)
diff --git a/internal/diagnosticwriter/diagnosticwriter.go b/internal/diagnosticwriter/diagnosticwriter.go
@@ -90,7 +90,7 @@ func writeCodeSnippet(writer io.Writer, sourceFile *ast.SourceFile, start int, l
 		lastLineChar++ // When length is zero, squiggle the character right after the start position.
 	}
 
-	lastLineOfFile, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, len(sourceFile.Text()))
+	lastLineOfFile := scanner.GetECMALineOfPosition(sourceFile, len(sourceFile.Text()))
 
 	hasMoreThanFiveLines := lastLine-firstLine >= 4
 	gutterWidth := len(strconv.Itoa(lastLine + 1))
@@ -357,7 +357,7 @@ func prettyPathForFileError(file *ast.SourceFile, fileErrors []*ast.Diagnostic,
 	if file == nil || len(fileErrors) == 0 {
 		return ""
 	}
-	line, _ := scanner.GetECMALineAndCharacterOfPosition(file, fileErrors[0].Loc().Pos())
+	line := scanner.GetECMALineOfPosition(file, fileErrors[0].Loc().Pos())
 	fileName := file.FileName()
 	if tspath.PathIsAbsolute(fileName) && tspath.PathIsAbsolute(formatOpts.CurrentDirectory) {
 		fileName = tspath.ConvertToRelativePath(file.FileName(), formatOpts.ComparePathsOptions)
diff --git a/internal/format/api.go b/internal/format/api.go
@@ -146,7 +146,7 @@ func FormatOnSemicolon(ctx context.Context, sourceFile *ast.SourceFile, position
 }
 
 func FormatOnEnter(ctx context.Context, sourceFile *ast.SourceFile, position int) []core.TextChange {
-	line, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, position)
+	line := scanner.GetECMALineOfPosition(sourceFile, position)
 	if line == 0 {
 		return nil
 	}
diff --git a/internal/format/indent.go b/internal/format/indent.go
@@ -68,7 +68,7 @@ func getIndentationForNodeWorker(
 			// })                    looking at the relationship between the list and *first* list item.
 			var listIndentsChild bool
 			if firstListChild != nil {
-				listLine, _ := getStartLineAndCharacterForNode(firstListChild, sourceFile)
+				listLine := getStartLineForNode(firstListChild, sourceFile)
 				listIndentsChild = listLine > containingListOrParentStartLine
 			}
 			actualIndentation := getActualIndentationForListItem(current, sourceFile, options, listIndentsChild)
@@ -134,7 +134,7 @@ func isArgumentAndStartLineOverlapsExpressionBeingCalled(parent *ast.Node, child
 		return false
 	}
 	expressionOfCallExpressionEnd := parent.Expression().End()
-	expressionOfCallExpressionEndLine, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, expressionOfCallExpressionEnd)
+	expressionOfCallExpressionEndLine := scanner.GetECMALineOfPosition(sourceFile, expressionOfCallExpressionEnd)
 	return expressionOfCallExpressionEndLine == childStartLine
 }
 
@@ -188,7 +188,7 @@ func deriveActualIndentationFromList(list *ast.NodeList, index int, sourceFile *
 			continue
 		}
 		// skip list items that ends on the same line with the current list element
-		prevEndLine, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, list.Nodes[i].End())
+		prevEndLine := scanner.GetECMALineOfPosition(sourceFile, list.Nodes[i].End())
 		if prevEndLine != line {
 			return findColumnForFirstNonWhitespaceCharacterInLine(line, char, sourceFile, options)
 		}
@@ -243,7 +243,7 @@ func childStartsOnTheSameLineWithElseInIfStatement(parent *ast.Node, child *ast.
 	if parent.Kind == ast.KindIfStatement && parent.AsIfStatement().ElseStatement == child {
 		elseKeyword := astnav.FindPrecedingToken(sourceFile, child.Pos())
 		debug.AssertIsDefined(elseKeyword)
-		elseKeywordStartLine, _ := getStartLineAndCharacterForNode(elseKeyword, sourceFile)
+		elseKeywordStartLine := getStartLineForNode(elseKeyword, sourceFile)
 		return elseKeywordStartLine == childStartLine
 	}
 	return false
@@ -253,6 +253,10 @@ func getStartLineAndCharacterForNode(n *ast.Node, sourceFile *ast.SourceFile) (l
 	return scanner.GetECMALineAndCharacterOfPosition(sourceFile, scanner.GetTokenPosOfNode(n, sourceFile, false))
 }
 
+func getStartLineForNode(n *ast.Node, sourceFile *ast.SourceFile) int {
+	return scanner.GetECMALineOfPosition(sourceFile, scanner.GetTokenPosOfNode(n, sourceFile, false))
+}
+
 func GetContainingList(node *ast.Node, sourceFile *ast.SourceFile) *ast.NodeList {
 	if node.Parent == nil {
 		return nil
@@ -438,8 +442,8 @@ func NodeWillIndentChild(settings *FormatCodeSettings, parent *ast.Node, child *
 			return rangeIsOnOneLine(child.Loc, sourceFile)
 		}
 		if parent.Kind == ast.KindBinaryExpression && sourceFile != nil && childKind == ast.KindJsxElement {
-			parentStartLine, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, scanner.SkipTrivia(sourceFile.Text(), parent.Pos()))
-			childStartLine, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, scanner.SkipTrivia(sourceFile.Text(), child.Pos()))
+			parentStartLine := scanner.GetECMALineOfPosition(sourceFile, scanner.SkipTrivia(sourceFile.Text(), parent.Pos()))
+			childStartLine := scanner.GetECMALineOfPosition(sourceFile, scanner.SkipTrivia(sourceFile.Text(), child.Pos()))
 			return parentStartLine != childStartLine
 		}
 		if parent.Kind != ast.KindBinaryExpression {
@@ -515,7 +519,7 @@ func NodeWillIndentChild(settings *FormatCodeSettings, parent *ast.Node, child *
 // branch beginning on the line that the whenTrue branch ends.
 func childIsUnindentedBranchOfConditionalExpression(parent *ast.Node, child *ast.Node, childStartLine int, sourceFile *ast.SourceFile) bool {
 	if parent.Kind == ast.KindConditionalExpression && (child == parent.AsConditionalExpression().WhenTrue || child == parent.AsConditionalExpression().WhenFalse) {
-		conditionEndLine, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, parent.AsConditionalExpression().Condition.End())
+		conditionEndLine := scanner.GetECMALineOfPosition(sourceFile, parent.AsConditionalExpression().Condition.End())
 		if child == parent.AsConditionalExpression().WhenTrue {
 			return childStartLine == conditionEndLine
 		} else {
@@ -526,8 +530,8 @@ func childIsUnindentedBranchOfConditionalExpression(parent *ast.Node, child *ast
 			//   ? 1 : (          L1: whenTrue indented because it's on a new line
 			//     0              L2: indented two stops, one because whenTrue was indented
 			//   );                   and one because of the parentheses spanning multiple lines
-			trueStartLine, _ := getStartLineAndCharacterForNode(parent.AsConditionalExpression().WhenTrue, sourceFile)
-			trueEndLine, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, parent.AsConditionalExpression().WhenTrue.End())
+			trueStartLine := getStartLineForNode(parent.AsConditionalExpression().WhenTrue, sourceFile)
+			trueEndLine := scanner.GetECMALineOfPosition(sourceFile, parent.AsConditionalExpression().WhenTrue.End())
 			return conditionEndLine == trueStartLine && trueEndLine == childStartLine
 		}
 	}
@@ -549,7 +553,7 @@ func argumentStartsOnSameLineAsPreviousArgument(parent *ast.Node, child *ast.Nod
 		}
 
 		previousNode := parent.Arguments()[currentIndex-1]
-		lineOfPreviousNode, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, previousNode.End())
+		lineOfPreviousNode := scanner.GetECMALineOfPosition(sourceFile, previousNode.End())
 		if childStartLine == lineOfPreviousNode {
 			return true
 		}
diff --git a/internal/format/rulecontext.go b/internal/format/rulecontext.go
@@ -584,8 +584,8 @@ func isSemicolonDeletionContext(context *FormattingContext) bool {
 		nextTokenStart = scanner.GetTokenPosOfNode(nextRealToken, context.SourceFile, false)
 	}
 
-	startLine, _ := scanner.GetECMALineAndCharacterOfPosition(context.SourceFile, context.currentTokenSpan.Loc.Pos())
-	endLine, _ := scanner.GetECMALineAndCharacterOfPosition(context.SourceFile, nextTokenStart)
+	startLine := scanner.GetECMALineOfPosition(context.SourceFile, context.currentTokenSpan.Loc.Pos())
+	endLine := scanner.GetECMALineOfPosition(context.SourceFile, nextTokenStart)
 	if startLine == endLine {
 		return nextTokenKind == ast.KindCloseBraceToken || nextTokenKind == ast.KindEndOfFile
 	}
diff --git a/internal/format/span.go b/internal/format/span.go
@@ -85,7 +85,7 @@ func getOwnOrInheritedDelta(n *ast.Node, options *FormatCodeSettings, sourceFile
 	previousLine := -1
 	var child *ast.Node
 	for n != nil {
-		line, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, withTokenStart(n, sourceFile).Pos())
+		line := scanner.GetECMALineOfPosition(sourceFile, withTokenStart(n, sourceFile).Pos())
 		if previousLine != -1 && line != previousLine {
 			break
 		}
@@ -242,10 +242,10 @@ func (w *formatSpanWorker) execute(s *formattingScanner) []core.TextChange {
 	w.formattingScanner.advance()
 
 	if w.formattingScanner.isOnToken() {
-		startLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, withTokenStart(w.enclosingNode, w.sourceFile).Pos())
+		startLine := scanner.GetECMALineOfPosition(w.sourceFile, withTokenStart(w.enclosingNode, w.sourceFile).Pos())
 		undecoratedStartLine := startLine
 		if ast.HasDecorators(w.enclosingNode) {
-			undecoratedStartLine, _ = scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, getNonDecoratorTokenPosOfNode(w.enclosingNode, w.sourceFile))
+			undecoratedStartLine = scanner.GetECMALineOfPosition(w.sourceFile, getNonDecoratorTokenPosOfNode(w.enclosingNode, w.sourceFile))
 		}
 
 		w.processNode(w.enclosingNode, w.enclosingNode, startLine, undecoratedStartLine, w.initialIndentation, w.delta)
@@ -305,7 +305,7 @@ func (w *formatSpanWorker) execute(s *formattingScanner) []core.TextChange {
 			if parent == nil {
 				parent = w.previousParent
 			}
-			line, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, tokenInfo.Loc.Pos())
+			line := scanner.GetECMALineOfPosition(w.sourceFile, tokenInfo.Loc.Pos())
 			w.processPair(
 				tokenInfo,
 				line,
@@ -343,11 +343,11 @@ func (w *formatSpanWorker) processChildNode(
 	}
 
 	childStartPos := scanner.GetTokenPosOfNode(child, w.sourceFile, false)
-	childStartLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, childStartPos)
+	childStartLine := scanner.GetECMALineOfPosition(w.sourceFile, childStartPos)
 
 	undecoratedChildStartLine := childStartLine
 	if ast.HasDecorators(child) {
-		undecoratedChildStartLine, _ = scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, getNonDecoratorTokenPosOfNode(child, w.sourceFile))
+		undecoratedChildStartLine = scanner.GetECMALineOfPosition(w.sourceFile, getNonDecoratorTokenPosOfNode(child, w.sourceFile))
 	}
 
 	// if child is a list item - try to get its indentation, only if parent is within the original range.
@@ -457,7 +457,7 @@ func (w *formatSpanWorker) processChildNodes(
 				break
 			} else if tokenInfo.token.Kind == listStartToken {
 				// consume list start token
-				startLine, _ = scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, tokenInfo.token.Loc.Pos())
+				startLine = scanner.GetECMALineOfPosition(w.sourceFile, tokenInfo.token.Loc.Pos())
 
 				w.consumeTokenAndAdvanceScanner(tokenInfo, parent, parentDynamicIndentation, parent, false)
 
@@ -578,7 +578,7 @@ func (w *formatSpanWorker) tryComputeIndentationForListItem(startPos int, endPos
 			return inheritedIndentation
 		}
 	} else {
-		startLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, startPos)
+		startLine := scanner.GetECMALineOfPosition(w.sourceFile, startPos)
 		startLinePosition := GetLineStartPositionForPosition(startPos, w.sourceFile)
 		column := FindFirstNonWhitespaceColumn(startLinePosition, startPos, w.sourceFile, w.formattingContext.Options)
 		if startLine != parentStartLine || startPos == column {
@@ -747,7 +747,7 @@ func (w *formatSpanWorker) processRange(r TextRangeWithKind, rangeStartLine int,
 	if !rangeHasError {
 		if w.previousRange == NewTextRangeWithKind(0, 0, 0) {
 			// trim whitespaces starting from the beginning of the span up to the current line
-			originalStartLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, w.originalRange.Pos())
+			originalStartLine := scanner.GetECMALineOfPosition(w.sourceFile, w.originalRange.Pos())
 			w.trimTrailingWhitespacesForLines(originalStartLine, rangeStartLine, NewTextRangeWithKind(0, 0, 0))
 		} else {
 			lineAction = w.processPair(r, rangeStartLine, parent, w.previousRange, w.previousRangeStartLine, w.previousParent, contextNode, dynamicIndentation)
@@ -797,8 +797,8 @@ func (w *formatSpanWorker) trimTrailingWhitespacesForRemainingRange(trivias []Te
 }
 
 func (w *formatSpanWorker) trimTrailingWitespacesForPositions(startPos int, endPos int, previousRange TextRangeWithKind) {
-	startLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, startPos)
-	endLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, endPos)
+	startLine := scanner.GetECMALineOfPosition(w.sourceFile, startPos)
+	endLine := scanner.GetECMALineOfPosition(w.sourceFile, endPos)
 
 	w.trimTrailingWhitespacesForLines(startLine, endLine+1, previousRange)
 }
@@ -909,8 +909,8 @@ func (w *formatSpanWorker) indentTriviaItems(trivia []TextRangeWithKind, comment
 
 func (w *formatSpanWorker) indentMultilineComment(commentRange core.TextRange, indentation int, firstLineIsIndented bool, indentFinalLine bool) {
 	// split comment in lines
-	startLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, commentRange.Pos())
-	endLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, commentRange.End())
+	startLine := scanner.GetECMALineOfPosition(w.sourceFile, commentRange.Pos())
+	endLine := scanner.GetECMALineOfPosition(w.sourceFile, commentRange.End())
 
 	if startLine == endLine {
 		if !firstLineIsIndented {
@@ -1033,7 +1033,7 @@ func (w *formatSpanWorker) consumeTokenAndAdvanceScanner(currentTokenInfo tokenI
 			if lineAction == LineActionNone {
 				// indent token only if end line of previous range does not match start line of the token
 				if savePreviousRange != NewTextRangeWithKind(0, 0, 0) {
-					prevEndLine, _ := scanner.GetECMALineAndCharacterOfPosition(w.sourceFile, savePreviousRange.Loc.End())
+					prevEndLine := scanner.GetECMALineOfPosition(w.sourceFile, savePreviousRange.Loc.End())
 					indentToken = lastTriviaWasNewLine && tokenStartLine != prevEndLine
 				}
 			} else {
diff --git a/internal/format/util.go b/internal/format/util.go
@@ -10,8 +10,8 @@ import (
 )
 
 func rangeIsOnOneLine(node core.TextRange, file *ast.SourceFile) bool {
-	startLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, node.Pos())
-	endLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, node.End())
+	startLine := scanner.GetECMALineOfPosition(file, node.Pos())
+	endLine := scanner.GetECMALineOfPosition(file, node.End())
 	return startLine == endLine
 }
 
@@ -77,7 +77,7 @@ func getCloseTokenForOpenToken(kind ast.Kind) ast.Kind {
 
 func GetLineStartPositionForPosition(position int, sourceFile *ast.SourceFile) int {
 	lineStarts := scanner.GetECMALineStarts(sourceFile)
-	line, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, position)
+	line := scanner.GetECMALineOfPosition(sourceFile, position)
 	return int(lineStarts[line])
 }
 
diff --git a/internal/ls/completions.go b/internal/ls/completions.go
@@ -2518,7 +2518,7 @@ func boolToPtr(v bool) *bool {
 }
 
 func getLineOfPosition(file *ast.SourceFile, pos int) int {
-	line, _ := scanner.GetECMALineAndCharacterOfPosition(file, pos)
+	line := scanner.GetECMALineOfPosition(file, pos)
 	return line
 }
 
@@ -3515,8 +3515,8 @@ func getContextualKeywords(file *ast.SourceFile, contextToken *ast.Node, positio
 	// Source: https://tc39.es/proposal-import-assertions/
 	if contextToken != nil {
 		parent := contextToken.Parent
-		tokenLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, contextToken.End())
-		currentLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, position)
+		tokenLine := scanner.GetECMALineOfPosition(file, contextToken.End())
+		currentLine := scanner.GetECMALineOfPosition(file, position)
 		if (ast.IsImportDeclaration(parent) ||
 			ast.IsExportDeclaration(parent) && parent.ModuleSpecifier() != nil) &&
 			contextToken == parent.ModuleSpecifier() &&
diff --git a/internal/ls/lsutil/asi.go b/internal/ls/lsutil/asi.go
@@ -98,7 +98,7 @@ func NodeIsASICandidate(node *ast.Node, file *ast.SourceFile) bool {
 		return true
 	}
 
-	startLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, node.End())
-	endLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, astnav.GetStartOfNode(nextToken, file, false /*includeJSDoc*/))
+	startLine := scanner.GetECMALineOfPosition(file, node.End())
+	endLine := scanner.GetECMALineOfPosition(file, astnav.GetStartOfNode(nextToken, file, false /*includeJSDoc*/))
 	return startLine != endLine
 }
diff --git a/internal/ls/lsutil/utilities.go b/internal/ls/lsutil/utilities.go
@@ -32,10 +32,10 @@ func ProbablyUsesSemicolons(file *ast.SourceFile) bool {
 			if lastToken != nil && lastToken.Kind == ast.KindSemicolonToken {
 				withSemicolon++
 			} else if lastToken != nil && lastToken.Kind != ast.KindCommaToken {
-				lastTokenLine, _ := scanner.GetECMALineAndCharacterOfPosition(
+				lastTokenLine := scanner.GetECMALineOfPosition(
 					file,
 					astnav.GetStartOfNode(lastToken, file, false /*includeJSDoc*/))
-				nextTokenLine, _ := scanner.GetECMALineAndCharacterOfPosition(
+				nextTokenLine := scanner.GetECMALineOfPosition(
 					file,
 					scanner.GetRangeOfTokenAtPosition(file, lastToken.End()).Pos())
 				// Avoid counting missing semicolon in single-line objects:
diff --git a/internal/scanner/scanner.go b/internal/scanner/scanner.go
@@ -2337,8 +2337,8 @@ func getErrorRangeForArrowFunction(sourceFile *ast.SourceFile, node *ast.Node) c
 	pos := SkipTrivia(sourceFile.Text(), node.Pos())
 	body := node.Body()
 	if body != nil && body.Kind == ast.KindBlock {
-		startLine, _ := GetECMALineAndCharacterOfPosition(sourceFile, body.Pos())
-		endLine, _ := GetECMALineAndCharacterOfPosition(sourceFile, body.End())
+		startLine := GetECMALineOfPosition(sourceFile, body.Pos())
+		endLine := GetECMALineOfPosition(sourceFile, body.End())
 		if startLine < endLine {
 			// The arrow function spans multiple lines,
 			// make the error span be the first line, inclusive.
@@ -2434,9 +2434,15 @@ func GetECMALineStarts(sourceFile ast.SourceFileLike) []core.TextPos {
 	return sourceFile.ECMALineMap()
 }
 
+func GetECMALineOfPosition(sourceFile ast.SourceFileLike, pos int) int {
+	lineMap := GetECMALineStarts(sourceFile)
+	return ComputeLineOfPosition(lineMap, pos)
+}
+
 func GetECMALineAndCharacterOfPosition(sourceFile ast.SourceFileLike, pos int) (line int, character int) {
 	lineMap := GetECMALineStarts(sourceFile)
 	line = ComputeLineOfPosition(lineMap, pos)
+	// !!! TODO: this is suspect; these are rune counts, not UTF-8 _or_ UTF-16 offsets.
 	character = utf8.RuneCountInString(sourceFile.Text()[lineMap[line]:pos])
 	return line, character
 }
diff --git a/internal/testutil/tsbaseline/type_symbol_baseline.go b/internal/testutil/tsbaseline/type_symbol_baseline.go
@@ -342,7 +342,7 @@ func forEachASTNode(node *ast.Node) []*ast.Node {
 
 func (walker *typeWriterWalker) writeTypeOrSymbol(node *ast.Node, isSymbolWalk bool) *typeWriterResult {
 	actualPos := scanner.SkipTrivia(walker.currentSourceFile.Text(), node.Pos())
-	line, _ := scanner.GetECMALineAndCharacterOfPosition(walker.currentSourceFile, actualPos)
+	line := scanner.GetECMALineOfPosition(walker.currentSourceFile, actualPos)
 	sourceText := scanner.GetSourceTextOfNodeFromSourceFile(walker.currentSourceFile, node, false /*includeTrivia*/)
 	fileChecker, done := walker.getTypeCheckerForCurrentFile()
 	defer done()
diff --git a/internal/transformers/utilities.go b/internal/transformers/utilities.go
@@ -253,8 +253,8 @@ func IsOriginalNodeSingleLine(emitContext *printer.EmitContext, node *ast.Node)
 	if source == nil {
 		return false
 	}
-	startLine, _ := scanner.GetECMALineAndCharacterOfPosition(source, original.Loc.Pos())
-	endLine, _ := scanner.GetECMALineAndCharacterOfPosition(source, original.Loc.End())
+	startLine := scanner.GetECMALineOfPosition(source, original.Loc.Pos())
+	endLine := scanner.GetECMALineOfPosition(source, original.Loc.End())
 	return startLine == endLine
 }
 

Original file line number	Diff line number	Diff line change
`@@ -798,8 +798,8 @@ func (c Checker) checkGrammarArrowFunction(node ast.Node, file *ast.SourceFile`
`798`	`798`	`}`
`799`	`799`
`800`	`800`	`equalsGreaterThanToken := arrowFunc.EqualsGreaterThanToken`
`801`		`- startLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, equalsGreaterThanToken.Pos())`
`802`		`- endLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, equalsGreaterThanToken.End())`
	`801`	`+ startLine := scanner.GetECMALineOfPosition(file, equalsGreaterThanToken.Pos())`
	`802`	`+ endLine := scanner.GetECMALineOfPosition(file, equalsGreaterThanToken.End())`
`803`	`803`	`return startLine != endLine && c.grammarErrorOnNode(equalsGreaterThanToken, diagnostics.Line_terminator_not_permitted_before_arrow)`
`804`	`804`	`}`
`805`	`805`
Original file line number	Diff line number	Diff line change
`@@ -1082,7 +1082,7 @@ func (p Program) getDiagnosticsWithPrecedingDirectives(sourceFile ast.SourceFi`
`1082`	`1082`	`// Build map of directives by line number`
`1083`	`1083`	`directivesByLine := make(map[int]ast.CommentDirective)`
`1084`	`1084`	`for _, directive := range sourceFile.CommentDirectives {`
`1085`		`- line, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, directive.Loc.Pos())`
	`1085`	`+ line := scanner.GetECMALineOfPosition(sourceFile, directive.Loc.Pos())`
`1086`	`1086`	`directivesByLine[line] = directive`
`1087`	`1087`	`}`
`1088`	`1088`	`lineStarts := scanner.GetECMALineStarts(sourceFile)`
Original file line number	Diff line number	Diff line change
`@@ -146,7 +146,7 @@ func FormatOnSemicolon(ctx context.Context, sourceFile *ast.SourceFile, position`
`146`	`146`	`}`
`147`	`147`
`148`	`148`	`func FormatOnEnter(ctx context.Context, sourceFile *ast.SourceFile, position int) []core.TextChange {`
`149`		`- line, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, position)`
	`149`	`+ line := scanner.GetECMALineOfPosition(sourceFile, position)`
`150`	`150`	`if line == 0 {`
`151`	`151`	`return nil`
`152`	`152`	`}`
Original file line number	Diff line number	Diff line change
`@@ -584,8 +584,8 @@ func isSemicolonDeletionContext(context *FormattingContext) bool {`
`584`	`584`	`nextTokenStart = scanner.GetTokenPosOfNode(nextRealToken, context.SourceFile, false)`
`585`	`585`	`}`
`586`	`586`
`587`		`- startLine, _ := scanner.GetECMALineAndCharacterOfPosition(context.SourceFile, context.currentTokenSpan.Loc.Pos())`
`588`		`- endLine, _ := scanner.GetECMALineAndCharacterOfPosition(context.SourceFile, nextTokenStart)`
	`587`	`+ startLine := scanner.GetECMALineOfPosition(context.SourceFile, context.currentTokenSpan.Loc.Pos())`
	`588`	`+ endLine := scanner.GetECMALineOfPosition(context.SourceFile, nextTokenStart)`
`589`	`589`	`if startLine == endLine {`
`590`	`590`	`return nextTokenKind == ast.KindCloseBraceToken \|\| nextTokenKind == ast.KindEndOfFile`
`591`	`591`	`}`
Original file line number	Diff line number	Diff line change
`@@ -10,8 +10,8 @@ import (`
`10`	`10`	`)`
`11`	`11`
`12`	`12`	`func rangeIsOnOneLine(node core.TextRange, file *ast.SourceFile) bool {`
`13`		`- startLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, node.Pos())`
`14`		`- endLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, node.End())`
	`13`	`+ startLine := scanner.GetECMALineOfPosition(file, node.Pos())`
	`14`	`+ endLine := scanner.GetECMALineOfPosition(file, node.End())`
`15`	`15`	`return startLine == endLine`
`16`	`16`	`}`
`17`	`17`
`@@ -77,7 +77,7 @@ func getCloseTokenForOpenToken(kind ast.Kind) ast.Kind {`
`77`	`77`
`78`	`78`	`func GetLineStartPositionForPosition(position int, sourceFile *ast.SourceFile) int {`
`79`	`79`	`lineStarts := scanner.GetECMALineStarts(sourceFile)`
`80`		`- line, _ := scanner.GetECMALineAndCharacterOfPosition(sourceFile, position)`
	`80`	`+ line := scanner.GetECMALineOfPosition(sourceFile, position)`
`81`	`81`	`return int(lineStarts[line])`
`82`	`82`	`}`
`83`	`83`
Original file line number	Diff line number	Diff line change
`@@ -98,7 +98,7 @@ func NodeIsASICandidate(node ast.Node, file ast.SourceFile) bool {`
`98`	`98`	`return true`
`99`	`99`	`}`
`100`	`100`
`101`		`- startLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, node.End())`
`102`		`- endLine, _ := scanner.GetECMALineAndCharacterOfPosition(file, astnav.GetStartOfNode(nextToken, file, false /includeJSDoc/))`
	`101`	`+ startLine := scanner.GetECMALineOfPosition(file, node.End())`
	`102`	`+ endLine := scanner.GetECMALineOfPosition(file, astnav.GetStartOfNode(nextToken, file, false /includeJSDoc/))`
`103`	`103`	`return startLine != endLine`
`104`	`104`	`}`