Using classes in firebase functions?

Question

I am writing code for a firebase function, the problem is that I need to use a class but when I call the class method the firebase function log shows this error:

ERROR:

ReferenceError: Proverbi is not defined
at exports.getProverbio.functions.https.onRequest (/srv/index.js:48:26)
at cloudFunction (/srv/node_modules/firebase-functions/lib/providers/https.js:49:16)
at /worker/worker.js:783:7
at /worker/worker.js:766:11
at _combinedTickCallback (internal/process/next_tick.js:132:7)
at process._tickDomainCallback (internal/process/next_tick.js:219:9)

Here's the "index.js" code:

//firebase deploy --only functions

// The Cloud Functions for Firebase SDK to create Cloud Functions and setup triggers.
const functions = require('firebase-functions');
// The Firebase Admin SDK to access the Firebase Realtime Database.
const admin = require('firebase-admin');
admin.initializeApp();

// Take the text parameter passed to this HTTP endpoint and insert it into the
// Realtime Database under the path /messages/:pushId/original
exports.addStanza = functions.https.onRequest(async (req, res) => {
    // Grab the text parameter.
    const nome = req.query.text;
    // Push the new message into the Realtime Database using the Firebase Admin SDK.
    const snapshot = await admin.database().ref('/stanze').push({giocatori: {giocatore:{nome:nome,punteggio:0}}});
    // Redirect with 303 SEE OTHER to the URL of the pushed object in the Firebase console.
    //res.redirect(200, nome.toString());
    var link = snapshot.toString().split('/');

    res.json({idStanza:link[4]});
});

// Listens for new messages added to /messages/:pushId/original and creates an
//  uppercase version of the message to /messages/:pushId/uppercase

 exports.addFirstPlayer = functions.database.ref('/stanze/{pushId}/giocatori/giocatore/nome')
.onCreate((snapshot, context) => {
  // Grab the current value of what was written to the Realtime Database.
  const nome = snapshot.val();
 // const snapshot3 = snapshot.ref('/stanza/{pushId}/giocatori/giocatore').remove();
  const snapshot2 =  snapshot.ref.parent.parent.remove();
  return snapshot.ref.parent.parent.push({nome:nome,punteggio:0});
});

exports.addPlayer = functions.https.onRequest(async (req, res) => {
  // Grab the text parameter.
  const nome = req.query.text;
  const idStanza = req.query.id;
  // Push the new message into the Realtime Database using the Firebase Admin SDK.
  const snapshot = await admin.database().ref('/stanz/'+idStanza+"/giocatori").push({nome:nome,punteggio:0 });
  // Redirect with 303 SEE OTHER to the URL of the pushed object in the Firebase console.
  //res.redirect(200, nome.toString());
  res.json({success:{id:idStanza}});
});

exports.getProverbio = functions.https.onRequest(async (req, res) => {
    const difficolta = req.query.difficolta;
    var proverbioClass = new Proverbi(2);
    var p = proverbioClass.getProverbio();
    var proverbio = p.split('-');
    var inizio = proverbio[0];
    var fine = proverbio[1];

    res.json({proverbio:{inizio:inizio,fine:fine,difficolta:difficolta}});
});

Here's the code that's causing the problem:

exports.getProverbio = functions.https.onRequest(async (req, res) => {
    const difficolta = req.query.difficolta;
    var proverbioClass = new Proverbi(2);
    var p = proverbioClass.getProverbio();
    var proverbio = p.split('-');
    var inizio = proverbio[0];
    var fine = proverbio[1];

    res.json({proverbio:{inizio:inizio,fine:fine,difficolta:difficolta}});
});

Here's the "Proverbi.class" code:

class Proverbi{
    constructor(n) {
        this.magicNumber = n;
    }
    getProverbio() {
        var text = "";
        switch (magicNumber) {
            case 1:
                text += ("Chip");
                text += ("-Chop");
                break; 
        }
        return text;
    }
}

How can I use the "Proverbi" class inside the "index.js"?

Answer 1

You need to add the definition of your Proverbi Class to the index.js file.

If you are just going to use this Class in the getProverbio Cloud Function, do as follows:

exports.getProverbio = functions.https.onRequest(async (req, res) => {


    class Proverbi {
        constructor(n) {
            this.magicNumber = n;
        }
        getProverbio() {

            var text = "";
            switch (this.magicNumber) {
                case 1:
                    text += ("Chip");
                    text += ("-Chop");
                    break;
            }
            return text;
        }
    }

    const difficolta = req.query.difficolta;
    var proverbioClass = new Proverbi(2);
    var p = proverbioClass.getProverbio();
    var proverbio = p.split('-');
    var inizio = proverbio[0];
    var fine = proverbio[1];

    res.json({ proverbio: { inizio: inizio, fine: fine, difficolta: difficolta } });
});

If you want to use the Class in other functions, just declare it as follows:

class Proverbi {
    constructor(n) {
        console.log(n);
    }
    getProverbio() {
        console.log(this.magicNumber);
        console.log(this.magicNumber);
        var text = "";
        switch (this.magicNumber) {
            case 1:
                text += ("Chip");
                text += ("-Chop");
                break;
        }
        return text;
    }
}

exports.getProverbio = functions.https.onRequest(async (req, res) => {

    const difficolta = req.query.difficolta;
    var proverbioClass = new Proverbi(2);
    var p = proverbioClass.getProverbio();
    var proverbio = p.split('-');
    var inizio = proverbio[0];
    var fine = proverbio[1];

    res.json({ proverbio: { inizio: inizio, fine: fine, difficolta: difficolta } });
});