use padStart

src/compiler/utils/get_code_frame.ts

@@ -18,9 +18,7 @@ export default function get_code_frame(
 		.slice(frame_start, frame_end)
 		.map((str, i) => {
 			const isErrorLine = frame_start + i === line;
-
+			const line_num = String(i + frame_start + 1).padStart(digits, ' ');
-			let line_num = String(i + frame_start + 1);
-			while (line_num.length < digits) line_num = ` ${line_num}`;
 
 			if (isErrorLine) {
 				const indicator = ' '.repeat(digits + 2 + tabs_to_spaces(str.slice(0, column)).length) + '^';