How to update an "array of objects" with Firestore and Firebase functions?

Question

I have some body data coming into firebase functions as a array ['123','hello','34']

I then process it by doing const data = JSON.stringify(['123','hello','34'])

After i update the firestore data by doing a set

set({testData : firestore.FieldValue.arrayUnion(data)})

Problem is, the entire thing is saved as string in firestore

testData: "['123','hello','34']"

Instead of an array.

testData: 
 0: "123"
 1: "hello"
 2: "34"

My question is how do i get firestore to save it as an array?

Dharmaraj · Accepted Answer · 2022-02-27 12:27:16Z

1

You are converting it to a string by using stringify(). Try refactoring the code as shown below:

docRef.set({ testData : firestore.FieldValue.arrayUnion(...data) })
// use spread operator here                             ^^^

The documentation (NodeJS) has an example on adding multiple values using arrayUnion.

answered Feb 27, 2022 at 12:27

Dharmaraj

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1 Comment

Nice, so i didn't need to do any conversions, thanks heaps !