在 Cloud Function 中使用 Cloud Firestore 数据

Question

I am trying to create Cloud Functions that would fetch data from Cloud Firestore, and send a payment request to a payment gateway API using the values fetched from Cloud Firestore.

I can fetch the document I need from Firestore using this function:

exports.getData = functions.https.onRequest((req, res) => {
  const docRef = db.collection('requests').doc('vsFyJ5lisBgYNwQEzOLa');
  const getDoc = docRef.get()
    .then(doc => {
      if (!doc.exists) {
        console.log('No such document!');
        return res.send('Not Found')
      } 
        console.log(doc.data());
        return res.send(doc.data());
    })
    .catch(err => {
      console.log('Error getting document', err);
      
    });
    
 });

However, this function only prints the document values; I need to use the values in another function like the one below:

exports.pay = functions.https.onRequest((req, res) => {
  var Iyzipay = require('iyzipay');
  const doc = db.collection('requests').doc('vsFyJ5lisBgYNwQEzOLa');
  const iyzipay = new Iyzipay({
    apiKey: 'apiKey',
    secretKey: 'secretKey',
      uri: 'https://sandbox-api.iyzipay.com'
  });
  var request = {
    locale: Iyzipay.LOCALE.TR,
    conversationId: '123456789',
    price: doc.price,
    paidPrice: doc.paidPrice,
    currency: Iyzipay.CURRENCY.TRY,
    installment: '1',
    basketId: 'B67832',
    paymentChannel: Iyzipay.PAYMENT_CHANNEL.WEB,
    paymentGroup: Iyzipay.PAYMENT_GROUP.PRODUCT,
    paymentCard: {
        cardHolderName: doc.cardHolderName,
        cardNumber: doc.cardNumber,
        expireMonth: doc.expireMonth,
        expireYear: doc.expireYear,
        cvc: doc.cvc,
        registerCard: '0'
    },
  };
iyzipay.payment.create(request, function (err, result) {
  console.log(err, result);
});
});

I tried to combine the functions like below:

exports.pay = functions.https.onRequest((req, res) => {
  var Iyzipay = require('iyzipay');
  const doc = db.collection('requests').doc('vsFyJ5lisBgYNwQEzOLa');
  const iyzipay = new Iyzipay({
    apiKey: 'sandbox-afXhZPW0MQlE4dCUUlHcEopnMBgXnAZI',
    secretKey: 'sandbox-wbwpzKIiplZxI3hh5ALI4FJyAcZKL6kq',
      uri: 'https://sandbox-api.iyzipay.com'
  });
  const docRef = db.collection('requests').doc('vsFyJ5lisBgYNwQEzOLa');
  const getDoc = docRef.get()
    .then(doc => {
      if (!doc.exists) {
        console.log('No such document!');
        return res.send('Not Found')
      } 
        console.log(doc.data());
        return res.send(doc.data());
    })
    .catch(err => {
      console.log('Error getting document', err);
      
    });
  var request = {
    locale: Iyzipay.LOCALE.TR,
    conversationId: '123456789',
    price: '1',
    paidPrice: '1.2',
    currency: Iyzipay.CURRENCY.TRY,
    installment: '1',
    basketId: 'B67832',
    paymentChannel: Iyzipay.PAYMENT_CHANNEL.WEB,
    paymentGroup: Iyzipay.PAYMENT_GROUP.PRODUCT,
    paymentCard: {
        cardHolderName: doc.cardHolderName,
        cardNumber: doc.cardNumber,
        expireMonth: doc.expireMonth,
        expireYear: doc.expireYear,
        cvc: doc.cvc,
        registerCard: '0'
    }        
  };
iyzipay.payment.create(request, function (err, result) {
  console.log(err, result);
});
});

The payment processor returned an error while the Firestore query printed on the console like before.

I then tried was to try the call to payment processor with static values like below:

var request = {
    locale: Iyzipay.LOCALE.TR,
    conversationId: '123456789',
    price: '1',
    paidPrice: '1.2',
    currency: Iyzipay.CURRENCY.TRY,
    installment: '1',
    basketId: 'B67832',
    paymentChannel: Iyzipay.PAYMENT_CHANNEL.WEB,
    paymentGroup: Iyzipay.PAYMENT_GROUP.LISTING,
    paymentCard: {
        cardHolderName: 'John Doe',
        cardNumber: '5528790000000008',
        expireMonth: '12',
        expireYear: '2030',
        cvc: '123',
        registerCard: '0'
}
}

And the payment processor returned success, so there must be something wrong with the way I fetch or use the Firestore document values.

To test once more if it was indeed using Firestore values, I switched only one field to cardNumber: doc.cardNumber . The console returned:

✔  functions[pay]: http function initialized (http://localhost:5000/highmidlow1/us-central1/pay).
i  functions: Beginning execution of "pay"
⚠  External network resource requested!
   - URL: "https://sandbox-api.iyzipay.com/payment/auth"
 - Be careful, this may be a production service.
⚠  Google API requested!
   - URL: "https://oauth2.googleapis.com/token"
   - Be careful, this may be a production service.
>  null {
>    status: 'failure',
>    errorCode: '12',
>    errorMessage: 'Invalid card number',
>    locale: 'tr',
>    systemTime: 1608311421424,
>    conversationId: '123456789'
>  }
>  {
>    expireYear: '2030',
>    paidPrice: 1.2,
>    cardNumber: '5528790000000008',
>    cvc: '123',
>    price: 1,
>    expireMonth: '12',  }

So how can I fetch a document from Firestore and use its values in a Cloud Function, like price: doc.price ?

Answer 1

I think you need to move your request logic into the .then(...) block because right now it looks like you're trying to use the document result outside of the block where it is actually returned, which might be why you're getting an "invalid card number" error.

The Firestore API uses Promises for most/all fetch operations so you'll always need to wait for the result before using it.

// ...
docRef.get().then(doc => {
    if (!doc.exists) {
        console.log('No such document!');
        return res.send('Not Found')
    }
    console.log(doc.data());
    res.send(doc.data());

    const request = { ... }
})

If you're using a node version that supports async/await , it might make it easier to spot these types of bugs.

const doc = await docRef.get()
if (!doc.exists) {
    console.log('No such document!');
    return res.send('Not Found')
}
console.log(doc.data());
res.send(doc.data());

const request = { ... }