Firebase Cloud Functions/每个then()应该返回一个值或抛出promise/always-return [英] Firebase Cloud Functions / Each then() should return a value or throw promise/always-return

问题描述

我一直遵循关于承诺的官方Firebase教程( https://www.youtube.com /watch?v = 7IkUgCLr5oA )，但就我而言，我无法使其正常工作.

I was following the official firebase tutorial on promises (https://www.youtube.com/watch?v=7IkUgCLr5oA) but in my case, I cannot make it work.

const promise = userRef.push({text:text});

const promise2 = promise.then((snapshot) => {
    res.status(200).json({message: 'ok!'});
});

promise2.catch(error => {
    res.status(500).json({message: 'error'});
});

我做错了什么?万一出现问题，每个then()应该都有其响应，但这就是为什么我要编写promise2 catch的原因.

What am I doing wrong? Each then() should have its response in case something goes wrong, but that is why I am writing the promise2 catch.

推荐答案

只需在发送响应之前添加return.

Just add the return before sending the response.

const promise = userRef.push({text:text});

const promise2 = promise.then((snapshot) => {
    return res.status(200).json({message: 'ok!'});
});

promise2.catch(error => {
    return res.status(500).json({message: 'error'});
});

您还可以按如下方式链接承诺:

Also you can chain the promises as follows:

return userRef.push({text:text})
.then((snapshot) => {
    return res.status(200).json({message: 'ok!'});

}).catch(error => {
    return res.status(500).json({message: 'error'});
});

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