javascript - ESLint 错误尝试部署函数 Firebase

Question

我尝试部署 fireabase 示例，但是当我尝试部署它时，CLI 启动错误:

[代码]

const functions = require('firebase-functions'); //to activate firebase functions

const admin = require('firebase-admin'); //to active firebase database permissions

admin.initializeApp(functions.config().firebase);

exports.addMessage = functions.https.onRequest((req, res) => {
// [END addMessageTrigger]
  // Grab the text parameter.
  const original = req.query.text;
  // [START adminSdkPush]
  // Push the new message into the Realtime Database using the Firebase Admin SDK.
  admin.database().ref('/messages').push({original: original}).then(snapshot => {
    // Redirect with 303 SEE OTHER to the URL of the pushed object in the Firebase console.
    res.redirect(303, snapshot.ref);
  });
  // [END adminSdkPush]
});

[错误]

  15:3   error  Expected catch() or return                  promise/catch-or-return
  15:69  error  Each then() should return a value or throw  promise/always-return

✖ 2 problems (2 errors, 0 warnings)


npm ERR! Darwin 17.4.0
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "--prefix" "/Users/user/test/functions" "run" "lint"
npm ERR! node v6.10.2
npm ERR! npm  v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! functions@ lint: `eslint .`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the functions@ lint script 'eslint .'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the functions package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     eslint .
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs functions
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!     npm owner ls functions
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR!     /Users/eliassebastian/Developer/npm-debug.log

Error: functions predeploy error: Command terminated with non-zero exit code1

我看一下 firebase 提供的原始 final here

我是 Javascript 和这个世界的新手，所以我真的迷失了这种类型的消息。

我该如何解决这个问题？

Answer 1

ESLint 警告是合法的。要获得关于每一个的更多详细信息，您可以使用它们的唯一 ID 进行搜索。例如:

15:3   error  Expected catch() or return                  promise/catch-or-return

这里警告的id是promise/catch-or-return。谷歌搜索“eslint promise/catch-or-return”发现 a plugin for ESLint将警告描述为:

Enforces the use of catch() on un-returned promises

你得到这个是因为你有一个从 then 返回的 promise ，但你永远不会 return 或 catch 可能的错误。

第二个警告:

15:69  error  Each then() should return a value or throw  promise/always-return

来自同一个 ESLint 插件，描述如下:

Return inside each then() to create readable and reusable Promise chains.

它要求您在 then 调用的每个函数中返回一个值，即使您没有任何特殊内容要发送到下一个 promise 链也是如此。

您可以像这样解决这两个问题:

admin.database().ref('/messages').push({original: original}).then(snapshot => {
    res.redirect(303, snapshot.ref);
    return null;
}).catch(error => {
    console.error(error);
    res.error(500);
});

注意 then block 现在返回 null，catch 用于从 then 返回的 promise 以捕获错误并发送错误回复客户。