Firebase在文档更新时获取数据库值

Question

当更新某些值时，我想在数据库中查找特定的值。然而，当我做firebase deploy时，我得到的是：

12 info lifecycle functions@~lint: Failed to exec lint script
13 verbose stack Error: functions@ lint: `tslint --project tsconfig.json`
13 verbose stack Exit status 2
13 verbose stack     at EventEmitter.<anonymous> (/usr/local/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:332:16)
13 verbose stack     at EventEmitter.emit (events.js:311:20)
13 verbose stack     at ChildProcess.<anonymous> (/usr/local/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
13 verbose stack     at ChildProcess.emit (events.js:311:20)
13 verbose stack     at maybeClose (internal/child_process.js:1021:16)
13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:286:5)
14 verbose pkgid functions@
15 verbose cwd /Users/u17495358/firecast
16 verbose Darwin 18.7.0
17 verbose argv "/usr/local/bin/node" "/usr/local/bin/npm" "--prefix" "/Users/u17495358/firecast/functions" "run" "lint"
18 verbose node v12.16.1
19 verbose npm  v6.13.4
20 error code ELIFECYCLE
21 error errno 2
22 error functions@ lint: `tslint --project tsconfig.json`
22 error Exit status 2
23 error Failed at the functions@ lint script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 2, true ]

这是我的功能代码：

import * as functions from 'firebase-functions';
import admin = require('firebase-admin');
admin.initializeApp()
export const onLocationUpdate = 
functions.firestore.document("users/{userId}").onUpdate(
change => {
let data = change.before.data();
console.log(data);
for (const key in data) {
const value = data[key];
console.log(value);
}
change.before.ref.get().then(document => {
console.log(document.data);
})
let payload = {
data: {
temp: String(""),
conditions: String("")
}
}
return admin.messaging().sendToTopic("users", payload)
}
)

如果我删除这个，效果会很好：

change.before.ref.get().then(document => {
console.log(document.data);
})

问题出在哪里？我该如何解决？

Answer 1

如果我像这样添加catch()，它会起作用：

change.before.ref.get().then(document => {
console.log(document.data);
}).catch(error => console.log(error))

有趣的是，根据Firebase文档，据说不需要catch()。