src/test-utils/chunk-test-helpers.ts

export function countLines(text: string): number {
  return text.split("\n").length;
}

export function hasBalancedFences(chunk: string): boolean {
  let open: { markerChar: string; markerLen: number } | null = null;
  for (const line of chunk.split("\n")) {
    const match = line.match(/^( {0,3})(`{3,}|~{3,})(.*)$/);
    if (!match) {
      continue;
    }
    const marker = match[2];
    if (!open) {
      open = { markerChar: marker[0], markerLen: marker.length };
      continue;
    }
    if (open.markerChar === marker[0] && marker.length >= open.markerLen) {
      open = null;
    }
  }
  return open === null;
}