为什么crypto.subtle.digest返回一个空对象

async function calculateDigest(data) {
  const encoder = new TextEncoder();
  const dataBuffer = encoder.encode(data);
  
  const digestBuffer = await crypto.subtle.digest('SHA-256', dataBuffer);
  
  // 将ArrayBuffer转换为十六进制字符串
  const digestArray = Array.from(new Uint8Array(digestBuffer));
  const digestHex = digestArray.map(byte => byte.toString(16).padStart(2, '0')).join('');
  
  return digestHex;
}

const data = 'Hello, world!';
calculateDigest(data)
  .then(digest => {
    console.log('Digest:', digest);
  })
  .catch(error => {
    console.error('Error:', error);
  });