klz-cables.com/lib/mdx-utils.ts

export function fixMdxDataProps(content: string): string {
  let fixedContent = content;
  let dataIndex = fixedContent.indexOf('data={{');

  while (dataIndex !== -1) {
    let openCount = 0;
    let endIndex = -1;
    const startObj = dataIndex + 6; // index of the first '{' in 'data={{'

    let inString = false;
    let isEscaped = false;

    for (let i = startObj; i < fixedContent.length; i++) {
      const char = fixedContent[i];

      if (isEscaped) {
        isEscaped = false;
        continue;
      }

      if (char === '\\') {
        isEscaped = true;
        continue;
      }

      if (char === '"') {
        inString = !inString;
        continue;
      }

      if (!inString) {
        if (char === '{') {
          openCount++;
        } else if (char === '}') {
          openCount--;
          if (openCount === 0) {
            endIndex = i;
            break;
          }
        }
      }
    }

    if (endIndex !== -1) {
      // jsonStr is the content INSIDE the outer curly braces
      const jsonStr = fixedContent.substring(startObj + 1, endIndex);
      const safeJsonStr = jsonStr.replace(/"/g, '&quot;');
      const replacement = `data="{${safeJsonStr}}"`;

      // We also need to consume the closing `}` of the `data={{`
      const nextCharIndex = endIndex + 1;
      const skipChars =
        nextCharIndex < fixedContent.length && fixedContent[nextCharIndex] === '}' ? 2 : 1;

      fixedContent =
        fixedContent.substring(0, dataIndex) +
        replacement +
        fixedContent.substring(endIndex + skipChars);

      dataIndex = fixedContent.indexOf('data={{', dataIndex + replacement.length);
    } else {
      // Malformed braces, prevent infinite loop
      break;
    }
  }

  return fixedContent;
}