Example code from the video "Use async/await with TypeScript in Cloud Functions"

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Example code from the video "Use async/await with TypeScript in Cloud Functions"

This is the example code from my video about using async/await with Cloud Functions. I've placed it here in a gist so it's easier to compare the "before" and "after" states for each case.

The code in this project is licensed under the Apache License 2.0.

Copyright 2018 Google LLC
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
    https://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

example1-1-before.ts

export const getBostonWeather = functions.https.onRequest((request, response) => {
    admin.firestore().doc("cities-weather/boston-ma-us").get()
    .then(snapshot => {
        const data = snapshot.data()
        response.send(data)
    })
    .catch(error => {
        // Handle the error
        console.log(error)
        response.status(500).send(error)
    })
})

example1-2-after.ts

export const getBostonWeather = functions.https.onRequest(async (request, response) => {
    try {
        const snapshot = await admin.firestore().doc("cities-weather/boston-ma-us").get()
        const data = snapshot.data()
        response.send(data)
    }
    catch (error) {
        // Handle the error
        console.log(error)
        response.status(500).send(error)
    }
})

example2-1-before.ts

export const getBostonAreaWeather = functions.https.onRequest((request, response) => {
    admin.firestore().doc("areas/greater-boston").get()
    .then(areaSnapshot => {
        const cities = areaSnapshot.data().cities
        const promises = []
        cities.forEach(city => {
            const p = admin.firestore().doc(`cities-weather/${city}`).get()
            promises.push(p)
        })
        return Promise.all(promises)
    })
    .then(snapshots => {
        const results = []
        snapshots.forEach(snap => {
            const data = snap.data()
            data.city = snap.id
            results.push(data)
        })
        response.send(results)
    })
    .catch(error => {
        console.log(error)
        response.status(500).send(error)
    })
})

example2-2-after.ts

export const getBostonAreaWeather = functions.https.onRequest(async (request, response) => {
    try {
        const areaSnapshot = await admin.firestore().doc("areas/greater-boston").get()
        const cities = areaSnapshot.data().cities
        const promises = []
        cities.forEach(city => {
            const p = admin.firestore().doc(`cities-weather/${city}`).get()
            promises.push(p)
        })

        const snapshots = await Promise.all(promises)

        const results = []
        snapshots.forEach(snap => {
            const data = snap.data()
            data.city = snap.id
            results.push(data)
        })

        response.send(results)
    }
    catch (error) {
        console.error(error)
        response.status(500).send(error)
    }
})

@Marcus-C137 for this to work you have to change these files in /functions directory to use ECMAScript2017

in .eslintrc.json

 "parserOptions": {
    // Required for certain syntax usages
    "ecmaVersion": 8
  },

and in package.json add

  "engines": {
    "node": "8"
  },

And then run npm install --save

@Marcus-C137 @ykabbara

I must admit that I haven't tested this, but I think you can fix it by defining the type in the array. From the code it looks like it should be an array of DocumentData objects.

add this import to index.ts if you don't have it to get firebase types:

import * as firebase from 'firebase';
And edit package.json to add in the firebase reference so it looks something like the following:

"dependencies": {`
   "firebase-admin": "~7.0.0",
   "firebase-functions": "^2.2.0",
   **"firebase": "^6.0.2"**
 },

Then edit the line where const results is created to read
const results: firebase.firestore.DocumentData [] = []

Like I said I didn't test this, so I'm not certain that DocumentData is the correct object type, You should be able to check it by calling typeof, and you can see the list in this doc: https://firebase.google.com/docs/reference/js/firebase.firestore.html.

I had a similar issue on my project when trying to pass a snapshot into an arrow function and fixed it by adding the type to the snapshot:
.then( (snapshot: firebase.firestore.QuerySnapshot) => {}

I hope that helps you and this isn't a red herring!

Hey... I think you need to update the code. 'cause I'm also having trouble with the problem as same as above.
I can't fix the error 'ts2532'

export const getBostonAreaWeather = functions.https.onRequest((request, response) => {
admin.firestore().doc("areas/greater-boston").get()
.then(areaSnapshot => {
const cities = areaSnapshot.data().cities
const promises: any[] | never[] | Promise<FirebaseFirestore.DocumentSnapshot>[] = []
cities.forEach((city: any) => {
const p = admin.firestore().doc(cities-weather/${city}).get()
promises.push(p)
})
return Promise.all(promises)
})
.then(snapshots => {
const results: any[] | never[] = []
snapshots.forEach(snap => {
const data = snap.data()
data.city = snap.id
results.push(data)
})
response.send(results)
})
.catch(error => {
console.log(error)
response.status(500).send(error)
})
})

Hi sir
I am getting six errors in this code ,its not working in my vs code its showing 6 errors
I think you have to update the code please help me

here is my error

src/index.ts:17:24 - error TS2532: Object is possibly 'undefined'.

17 const cities = areaSnapshot.data().cities
~~~~~~~~~~~~~~~~~~~

src/index.ts:18:15 - error TS7034: Variable 'promises' implicitly has type 'any[]' in some locations where its type cannot be determined.

18 const promises = []
~~~~~~~~

src/index.ts:19:24 - error TS7006: Parameter 'city' implicitly has an 'any' type.

19 cities.forEach(city => {
~~~~

src/index.ts:24:45 - error TS7005: Variable 'promises' implicitly has an 'any[]' type.

24 const snapshots = await Promise.all(promises)
~~~~~~~~

src/index.ts:26:15 - error TS7034: Variable 'results' implicitly has type 'any[]' in some locations where its type cannot be determined.

26 const results = []
~~~~~~~

src/index.ts:33:23 - error TS7005: Variable 'results' implicitly has an 'any[]' type.

33 response.send(results)
~~~~~~~

Found 6 errors.

npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! functions@ build: tsc
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the functions@ build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

to ignore errors like ' Object is possibly 'undefined'.' :
go to tsconfig.json and add "strictNullChecks":false

I'm missing examples with pubsub topics.

@vinod-hosamani @tkhduracell
I had the same errors with you, and fixed them with the following steps.

Step 1. To configure the file "functions/tsconfig.json" :
disable the line : "strict": true, ( in compilerOptions {...} )
enable a new option: "noImplicitAny": false (in compilerOptions {...} )
add a new line: "strictNullChecks":false. ( after "include": ["src"],)

Step 2. In the command line, run "npm install -g tslint"

Step 3. in the command line, run "npm run-script build "

After the step 1, the new file "functions/tsconfig.json" should be like
{ "compilerOptions": { "module": "commonjs", "noImplicitReturns": true, "noUnusedLocals": true, "outDir": "lib", "sourceMap": true, // "strict": true, "target": "es2017", "noImplicitAny": false }, "compileOnSave": true, "include": [ "src" ], "strictNullChecks":false }

@vinod-hosamani @tkhduracell
I had the same errors with you, and fixed them with the following steps.

Step 1. To configure the file "functions/tsconfig.json" :
disable the line : "strict": true, ( in compilerOptions {...} )
enable a new option: "noImplicitAny": false (in compilerOptions {...} )
add a new line: "strictNullChecks":false. ( after "include": ["src"],)

Step 2. In the command line, run "npm install -g tslint"

Step 3. in the command line, run "npm run-script build "

After the step 1, the new file "functions/tsconfig.json" should be like
{ "compilerOptions": { "module": "commonjs", "noImplicitReturns": true, "noUnusedLocals": true, "outDir": "lib", "sourceMap": true, // "strict": true, "target": "es2017", "noImplicitAny": false }, "compileOnSave": true, "include": [ "src" ], "strictNullChecks":false }

@BoHuang2018 This worked for me!! 60 mins of fussing and just needed a config tweak... lol

Just wanted to say I stumbled on this code and it was a great help to unblock me in a project. Thank you! 🥇