谷歌函数在访问body值时中断

Question

我想使用谷歌函数来处理一些帖子数据并返回它。虽然它在本地运行良好，但我无法让它在谷歌服务器上工作。

这个"功能"：

exports.helloWorld = (req, res) => {
  res.set('Access-Control-Allow-Methods', 'GET, HEAD, OPTIONS, POST');
  res.set('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
  res.set('Access-Control-Allow-Origin', '*');
  //res.status(200).send({"req.body.message": req.body.message});
  res.status(200).send({"req.body.message.length": req.body.message.length});
  return;
};

将失败并显示此请求：

fetch("https://us-central1-{myproject}.cloudfunctions.net/demo",
    {
      body: JSON.stringify({"message":"hello"}),
      method: "POST",
      headers: {
        'Content-Type': 'application/json'
      },
      mode: "cors"
    }
  ).then(response => response.json())
    .then(d => console.log(d))
TypeError: Cannot read property 'length' of undefined
    at exports.helloWorld (/user_code/index.js:17:76)
    at ...

而与其他 res.status 相同的方法...注释的行将起作用并返回 {req.body.message： "hello"}

在本地这有效..知道为什么这会破裂吗？

Answer 1

问题是，我没有检查request.method。浏览器发出了预检选项请求 - 这个请求失败了，因为那里没有 req.body.message。所以真正的 POST 请求从未发生过。

这解决了它：

  exports.helloWorld = (req, res) => {
      if (req.method === 'POST') {
      res.set('Access-Control-Allow-Origin', '*')
        .set('Access-Control-Allow-Methods', 'GET, HEAD, OPTIONS, POST')
        .set('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
        .set('Access-Control-Allow-Credentials', false)
        .status(200).send({"req.body.message.length": req.body.message.length });
      }
      else {
        res.set('Access-Control-Allow-Origin', '*')
        .set('Access-Control-Allow-Methods', 'GET, HEAD, OPTIONS, POST')
        .set('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
        .set('Access-Control-Allow-Credentials', false)
        .status(200).send();
      }
    };

Answer 2

尝试如下操作：

res.set('Access-Control-Allow-Origin', '*')
    .set('Access-Control-Allow-Methods', 'GET, HEAD, OPTIONS, POST')
    .set('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept')
    .set('Access-Control-Allow-Credentials', false)
    .status(200).send({"req.body.message": req.body.message.length });