update doc with arrayUnion gives error

[udarts]

Issue

I am trying to update a document in firestore, to add users uid to a userhasread array, but using the following code, gives an error:

setAnnounceToRead(userId) {
        let doc = firebase.firestore().collection('announcements').doc(this.state.id);
        doc.update({ "userhasread": firebase.firestore.FieldValue.arrayUnion(userId) });
}

It produces the following error:

undefined is not an object (evaluating '_firebase.default.firestore.FieldValue.arrayUnion')

Both: this.state.id and userId exist (did a console.log on both).

---

Project Files

iOS

ios/Podfile:

• [x ] I'm not using Pods
• [] I'm using Pods and my Podfile looks like:

# N/A

AppDelegate.m:

// N/A

---

Android

android/build.gradle:

// N/A

android/app/build.gradle:

// N/A

android/settings.gradle:

// N/A

MainApplication.java:

// N/A

AndroidManifest.xml:

<!-- N/A -->

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Environment

• Platform that you're experiencing the issue on:
  • iOS
  • Android
  • iOS but have not tested behavior on Android
  • Android but have not tested behavior on iOS
  • Both
• If known, the version of the platform are you experiencing the issue on:
  • ADD_SOMETHING_HERE e.g. iOS 10 or Android API 28
• Operating System:
  • MacOS, version: N/A
  • Windows, version: N/A
  • Other, please specify: N/A
• Build Tools:
  • Xcode 10
  • Android studio (latest version)
• **React Native version: **
  • 0.57.8
• **React Native Firebase library version: **
  • 5.1.1
• Firebase module(s) you're using that has the issue:
  • N/A
  • Authentication
  • Analytics
  • Cloud Firestore
  • Cloud Messaging (FCM)
  • Crashlytics
  • Dynamic Links
  • Functions Callable
  • Invites
  • Instance ID
  • Notifications
  • Performance Monitoring
  • Realtime Database
  • Remote Config
  • Storage
• Are you using TypeScript?
  • No
  • Yes, version: N/A
• Are you using Expo, e.g. ExpoKit?
  • No
  • Yes, I've not ejected
  • Yes, but I have ejected to ExpoKit
  • Yes, but I have ejected to vanilla React Native
  • Expo version: N/A

---

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[udarts]

Any idea on this issue?

[Salakar]

@udarts what does firebase var point to - your code, is this import firebase from 'react-native-firebase'; exactly or are you passing it around through redux or something like that?

[udarts]

Imported from react-native-firebase

[udarts]

Oh, sorry missed a small thing, I am loading the react-native-firebase in a separate file and them loading that file in every component I use.

The file looks like the following:

import RNfirebase from 'react-native-firebase';

const instance = RNfirebase.app();

export default instance;

[Salakar]

Ok thanks, that'll be your problem then - the statics are only accessible from the module export and not the app() instance; so you'll need to use that:

import rnfirebase from 'react-native-firebase';

// correct
rnfirebase.firestore.FieldValue.arrayUnion(userId);

// incorrect (what you're doing currently)
rnfirebase.app().firestore.FieldValue.arrayUnion(userId);

Hope that helps, will close the issue now.

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[udarts]

Thanks for your reply. Although it might be a bit different, this is how it is setup on my end:

I have a file called: firebase.js, inside is the code I posted above:

import RNfirebase from 'react-native-firebase';

const instance = RNfirebase.app();

export default instance;

Then on multiple components I call that firebase.js file like the following:

import firebase from '../firebase';

Then in that way I am calling:

firebase.firestore.FieldValue.arrayUnion(userId)

Am I missing anything?

[udarts]

@Salakar Any idea on this?

[udarts]

@Salakar I've made a change and now use import firebase from 'react-native-firebase';.

When I now try to update a doc with the following code:

setAnnounceToRead(userId) {
        let doc = firebase.firestore().collection('announcements').doc(this.state.id);
        doc.update({ "userhasread": firebase.firestore.FieldValue.arrayUnion(userId) });
}

In Firestore it is shown as:

userhasread: [
    0: useruid
]

While I thought it should be:

userhasread: [
   useruid
]

[akhil-ga]

A similar case like this one #1776 (comment) for me too.

Code

 const updateObj = {
      priorityMarkerId:  firebase.firestore.FieldValue.arrayUnion(uid),
    };

export const updateMyCollection = async (id, updateObj) => {
  try {
    await firebase
      .firestore()
      .collection('myCollection')
      .doc(id)
      .set(updateObj, { merge: true });
    return {
      status: 'success'
    };
  } catch (error) {
    return {
      status: 'error',
      message: error.message
    };
  }
};

Screenshot from firebase database

Console Log of updating object.