Function mapRenderedOffsetToRawIndex

packages/cli/src/transform.ts:1303–1337

(rawText: string, renderedOffset: number, bias: "start" | "end" = "start")

}

function mapRenderedOffsetToRawIndex(rawText: string, renderedOffset: number, bias: "start" | "end" = "start"): number {
  if (renderedOffset <= 0) return 0;

  let renderedIndex = 0;
  let rawIndex = 0;

  while (rawIndex < rawText.length) {
    const char = rawText[rawIndex];
    if (isCollapsibleWhitespaceChar(char)) {
      const runStart = rawIndex;
      while (rawIndex < rawText.length && isCollapsibleWhitespaceChar(rawText[rawIndex])) {
        rawIndex++;
      }

      if (renderedIndex === renderedOffset) {
        return bias === "end" ? rawIndex : runStart;
      }

      renderedIndex += 1;
      if (renderedIndex >= renderedOffset) {
        return bias === "end" ? rawIndex : runStart;
      }
      continue;
    }

    if (renderedIndex === renderedOffset) {
      return rawIndex;
    }

    rawIndex++;
    renderedIndex++;
  }

  return rawText.length;
}

function findTextDiff(oldText: string, newText: string): { oldSubstring: string; newSubstring: string; prefixLen: number } | null {
  if (oldText === newText) return null;