How to get value from Firestore using Firebase Functions?

Question

I would like to do a very basic request, to get the textvalue of my document 'LA'. I need to retrieve the value before doing others things with it.

async function getValue() {

  doc = await admin.firestore().doc('cities/LA').get();
  console.log('Authorized User Data From Function:', doc.data());
  result = doc.data().text;
  return result;
}

app.get('/hello-world',  async(req, res) => {

  console.log("before" );

  var text = getValue();

  console.log(text);
  //...do something with text

  console.log("after" );

  return res.status(200).send("sent !");

});
module.exports.app = functions.https.onRequest(app);

I have no errors when I deploy.

/Users/user/Documents/APP TEST/functions/index.js
  170:12  warning  Avoid nesting promises          promise/no-nesting
  170:12  warning  Avoid nesting promises          promise/no-nesting
  173:12  warning  Unexpected function expression  prefer-arrow-callback
  180:12  warning  Unexpected function expression  prefer-arrow-callback

✖ 4 problems (0 errors, 4 warnings)
  0 errors and 2 warnings potentially fixable with the `--fix` option.

✔  functions: Finished running predeploy script.
i  functions: ensuring necessary APIs are enabled...
✔  functions: all necessary APIs are enabled
i  functions: preparing functions directory for uploading...
i  functions: packaged functions (42.45 KB) for uploading
✔  functions: functions folder uploaded successfully
i  functions: updating Node.js 8 function app(us-central1)...
i  functions: updating Node.js 8 function sendIAPAnalytics(us-central1)...
✔  scheduler: all necessary APIs are enabled
✔  functions[sendIAPAnalytics(us-central1)]: Successful update operation. 
✔  functions[app(us-central1)]: Successful update operation. 

✔  Deploy complete!

Expected logs:

before
Authorized User Data From Function:
<my text value>
after

Displayed logs:

>Function execution started
>Function execution took 517 ms, finished with status code: 200

and nothing else :(

What's wrong?

I also tried the solution of this post without success, nothing is displayed: https://stackoverflow.com/a/55240125/2123039

Thanks

EDIT 1: No more logs adding try/catch block:

async function getValue() {

  try {
    doc = await admin.firestore().collection('cities').doc("LA").get();
    console.log('Authorized User Data From Function:', doc.data());
    result = doc.data();
    return result;

  } catch(e) {
    console.log(e);
  }

}

can you write your `await admin.firestore().doc('cities/LA').get();` inside a try catch block, to check if there is any error coming up — HexaCrop, Oct 17 '19 at 10:06
@KevinRED, please see my edits, logs are the same, so empty :( — cmii, Oct 17 '19 at 10:27
Do one thing make your console logs as console.error for now. Once the code is executed check in firebase console and filter the logs with errors. Most of the time it will take some time for firebase to show the logs in cloud. — HexaCrop, Oct 17 '19 at 10:32
Add an `await` when calling async function `getValue()` i.e. `var text = await getValue()` — William Chong, Oct 17 '19 at 10:49

Renaud Tarnec · Accepted Answer · 2019-10-17T10:51:57.607

By doing async function getValue() {...} you are declaring an asynchronous function (which is correct, since the get() function is asynchronous). But then you need to call it as follows

app.get('/hello-world',  async(req, res) => {

  console.log("before" );

  const text = await getValue();   // <- Here use await

  console.log(text);
  //...do something with text

  console.log("after" );

  return res.status(200).send("sent !");

});

How to get value from Firestore using Firebase Functions?

1 Answers1