FR: Firestore Web SDK React-Native/Expo support for Android devices

[samsafay]

Describe your environment

• Operating System version: Android 4.4.2
• Firebase SDK version: "^4.6.0"
• Firebase Product: Firestore Web SDK
• Expo: "^22.0.0"

Describe the problem

I am using Expo and trying to do basic CRUD with Firestore on an Android device and not getting any results. The same code works perfectly on an iOS device, but it doesn't work with Android. Can you take a look into that?

Steps to reproduce:

Basically create a react-native project, and Try any CRUD with Firestore. In my case fetching data from restaurants collection. Note, I am implementing Redux so you have to install 'react-redux' with your Expo project. As I said this code works perfectly with iOS but not with ANDROID. Let me know if you need more information.
Just tried this on react-native init project and got this error on my emulator. I just realized that this issue is related to #97.

Relevant Code:

import firebase from 'firebase';
import 'firebase/firestore';
import { Alert } from 'react-native';
import {
    RESTAURANTS_FETCH_SUCCESS,
} from './types';

export const restaurantsFetch = () => async dispatch => {
    try {
        const response = await firebase.firestore().collection('restaurants').get();
        response.forEach(doc => {
            dispatch({ type: RESTAURANTS_FETCH_SUCCESS, payload: { ...doc.data(), id: doc.id } });
        });
    } catch (err) {
        Alert.alert(err.message);
    }
};

[google-oss-bot]

Hmmm this issue does not seem to follow the issue template. Make sure you provide all the required information.

[fweffort]

hmmm this answer is not very welcoming to people trying to use your new product(firestore) and helping you identify errors.
It does not follow the issue template, but it's perfectly understandable.

Motivation for or Use Case - It is an error for everyone trying to use expo+firestore on ANDROID
Related Issues - Nope!
Environment Configuration -
It is a problem with android only,on your COMPETITOR's, ios, works fine, shouldn't android work flawlessly with google firestore?

Reproduce the Error -
create an app with create-react-native-app, following the guides from the documentation,
try and query any collection using ios and console.log the output. IT WORKS
same result is expected using android, but no error is thrown, and neither any result shown.

Why is it important?
Several new developers are using CRNA, following the documentation leads to Expo, and people enjoy it, people are going to start developing for ios only, or not using your brand new product at all.

Thanks for the welcoming answers on people trying to help you make better products!
Cheers!

[czubocha]

+1

[mitchhankins01]

+1 same issue

[mikelehen]

FYI- If anybody can help isolate what's going wrong under react native on Android, that would potentially expedite the resolution of this bug. A good first step might be to capture logging with firebase.firestore.setLogLevel('debug'), though debugging through the code may also be necessary.

[chrisbianca]

If you're happy to move away from Expo, then https://github.com/invertase/react-native-firebase has full support for Firestore on both Android and iOS already.

[harisvsulaiman]

@chrisbianca I have moved on to https://github.com/invertase/react-native-firebase, but some projects require the ease and features of expo and where performance is not a problem.

[clarktank]

If you are interested in Firestore vote here. https://expo.canny.io/feature-requests/p/adding-react-native-firebase-to-expo

[david1820]

+1 Same issue.

[dmitriy-bizyaev]

I think i've found the cause of this bug. The problem is not in Firestore library itself, but in the underlying WebChannel client. When it tries to make a GET request, it calls XMLHttpRequest.prototype.send with an empty string, which makes it fail on Android for some reason. Here's a workaround:

const originalSend = XMLHttpRequest.prototype.send;
XMLHttpRequest.prototype.send = function(body) {
  if (body === '') {
    originalSend.call(this);
  } else {
    originalSend.call(this, body);
  }
};

Apply this hack before making any calls to Firestore.

[mikelehen]

@dmitriy-bizyaev Wow! Thanks for tracking this down and providing the workaround. This is super helpful.

@wenbozhu Do you think it makes sense to make this change in WebChannel itself? Or perhaps we should file a bug against the React Native XMLHttpRequest implementation for Android...

[harisvsulaiman]

@mikelehen we could file an issue and see what they have to say, if its a breaking change ( i doubt it ),we can patch it here.

[wenbozhu]

if xhr.send("") works on iOS, then we should file a bug for Andriod React Native.

===

I would also like to see a patch in closure to avoid calling xhr.send("") for GET.

@tyoshino does the xhr2 api spec say anything about passing "" vs "undefined" body-content for a GET?

[mikelehen]

If anybody's willing, I'd appreciate it if somebody could test a patched version of the Firestore SDK that should (hopefully) now work with React Native on Android.

Probably only one of these is necessary, but to be safe:

1. Copy https://gist.githubusercontent.com/mikelehen/2d36ed9ce5a93c879670f1eaa398ad48/raw/23576d4a5e0cad6c101d29278bc801481992e015/firebase-firestore.js over your node_modules/firebase/firebase-firestore.js
2. Copy https://gist.githubusercontent.com/mikelehen/444950a35019208f3aaf18d37ab4937c/raw/c66d06fa0dcd03f353353deedcac7b5b9090d153/index.js over your node_modules/@firebase/webchannel-wrapper/dist/index.js

This will let us confirm that the change to WebChannel to avoid calling xhr.send('') does indeed resolve the issue. Thanks!

[clarktank]

@mikelehen I have replaced the two files but I am still getting the same error.
I tried to go through the code, but couldn't find @dmitriy-bizyaev's change. Can you show us on github what part of the file you have changed?

[clarktank]

[exp] Firestore (4.6.1) 2017-11-17T17:31:28.977Z [MemoryPersistence]: Starting transaction: Start LocalStore
[exp] Firestore (4.6.1) 2017-11-17T17:31:28.979Z [MemoryPersistence]: Starting transaction: Get last stream token
[exp] Firestore (4.6.1) 2017-11-17T17:31:28.980Z [MemoryPersistence]: Starting transaction: Get next mutation batch
[exp] Firestore (4.6.1) 2017-11-17T17:31:28.985Z [MemoryPersistence]: Starting transaction: Allocate query
[exp] Firestore (4.6.1) 2017-11-17T17:31:28.987Z [MemoryPersistence]: Starting transaction: Execute query
[exp] Firestore (4.6.1) 2017-11-17T17:31:28.989Z [MemoryPersistence]: Starting transaction: Remote document keys
[exp] Firestore (4.6.1) 2017-11-17T17:31:28.995Z [Connection]: Creating WebChannel: https://firestore.googleapis.com/google.firestore.v1beta1.Firestore/Listen/channel [object Object]
[exp] Firestore (4.6.1) 2017-11-17T17:31:29.006Z [Connection]: Opening WebChannel transport.
[exp] Firestore (4.6.1) 2017-11-17T17:31:29.008Z [Connection]: WebChannel sending: {"database":"projects/expo-sample/databases/(default)","addTarget":{"query":{"structuredQuery":{"from":[{"collectionId":"reviews"}],"orderBy":[{"field":{"fieldPath":"__name__"},"direction":"ASCENDING"}]},"parent":"projects/expo-sample/databases/(default)"},"targetId":2}}
[exp] Firestore (4.6.1) 2017-11-17T17:31:29.153Z [Connection]: WebChannel transport opened.

[mikelehen]

Thanks for checking @clarktank. The actual code change is in the closure-library code included via our dependency on closure-builder and ends up minified here, so it's a bit hard to highlight the change, but basically, this:

F(this.b,U(this,"Sending request")),this.o=!0,this.a.send(t),this.o=!1

changed to:

F(this.b,U(this,"Sending request")),this.o=!0,void 0!==n||"GET"!==e?this.a.send(t):this.a.send(),this.o=!1

in the files I posted (depending which file you look at the exact variable names might be different, but you can search for 'Sending request' to find the section).

If you can verify that the updated code is getting hit but still not working, that would be very useful to know. Else, we'll have to get a local repro set up and debug through it, but I'm not sure when that will happen.

[wenbozhu]

The closure change makes sure that for a GET, send() will be called instead of send(''). Isn't send('') the root cause of this issue?

===

Closure calls send('') when body is unspecified mostly to force the C-L header for formdata.

[clarktank]

Here is how to setup Expo/React-native. It took me about 7 min.
I have created a file that fetches from firestore database.
Create a virtual machine like Ubuntu:

1. sudo npm install -g exp
2. go to your workspace directory and put sudo exp init test-project
3. cd in to the test-project folder and enter npm install --save firebase
4. replace the App.js file in the test-project directory with this code https://github.com/clarktank/firestore-for-expo-team/blob/master/App.js
5. then in the test-project directory enter sudo exp start --tunnel
6. scan the QR code from your phone.
7. you can see the console log in the terminal that you entered sudo exp start --tunnel

[samsafay]

I solved the problem.
Change this, on line 2339:
void 0 !== c || "GET" !== b ? this.a.send(a) : this.a.send(),
with
void 0 != c || "GET" !== b ? this.a.send(a) : this.a.send(),

in the file node_modules\@firebase\webchannel-wrapper\dist\index.js
How to see that file correctly? Get prettier package on VS Code and press alt+shif+f.

To get rid of the runtime error, change:
const MAX_TIMER_DURATION_MS = 60 * 1000;
to
const MAX_TIMER_DURATION_MS = 6000 * 1000;

in your node_modules\react-native\Libraries\Core\Timers\JSTimers.js

[mikelehen]

@samsafay Thanks! That is very helpful. I'll sync up with folks internally to try to get the original fix reworked.

[josealfonsoweb]

Hey @samsafay I tried to do the changes, but I get the same error, Maybe I did anything wrong...can you help me to get this file fixed? how can I download it? will this allow me to use firestore in React Native with EXPO?

[josealfonsoweb]

Hey mikelehen @mikelehen I think you already found the solution... When will This issue be resolved? I want to use firestore in React Native with EXPO

[samsafay]

https://gist.github.com/samsafay/810037a1df791f3d0fab1d92a70aabd2
Replace this file with your node_modules/@firebase/webchannel-wrapper/dist/index.js
Make sure you copy paste from the raw.

Don't confuse this with the original fix that mikelehen sent. The original fix didn't work and needed to be modified a little. The new fix is highlighted here: https://gist.github.com/samsafay/810037a1df791f3d0fab1d92a70aabd2#file-index-js-L2339
Now, with this fix, you can use Firestore with Expo or wait for Google to internally patch it and release it in their next version of Firebase.

If you are getting a runTime error you can fix that by changing

const MAX_TIMER_DURATION_MS = 60 * 1000;
to
const MAX_TIMER_DURATION_MS = 6000 * 1000;

in your node_modules\react-native\Libraries\Core\Timers\JSTimers.js

[mikelehen]

Per my previous comment about the fix on our end having to be rolled back, I think we need to try to get React Native fixed. I looked a bit through the code and I suspect the problem is here: https://github.com/facebook/react-native/blob/cb49877a25bac9e72de85f6703eba7f07a308061/ReactAndroid/src/main/java/com/facebook/react/modules/network/NetworkingModule.java#L238

If it falls into the else block then I think contentType will be null and it'll hit an error. I think the fix is probably to change the if (data == null) { line to

// The spec (https://xhr.spec.whatwg.org/#dom-xmlhttprequest-send) defines GET and HEAD to be treated as if the body was null.
if (data == null || method.toLowerCase() === 'get' || method.toLowerCase() === 'head') {

If anybody wants to try to verify this and get a PR submitted to React Native, it would be much appreciated. Else, I'll just log a bug against React Native in the next few days.

[mikelehen]

Anybody willing to create a react-native PR based on my comment above? :-)

[mikelehen]

I also have a suggested fix for the timer warning (facebook/react-native#17083) which somebody could submit a PR for. :-)

[samsafay]

@mikelehen I have a great news, the solution works like a charm! Lets hope Facebook accepts it...

[mikelehen]

Thanks! I see though that my fix had syntax errors (because I forgot it's java). Agh. Sorry!

[NickDelfino]

Has there been any official closure on this? Are the fixes in the various SDKs or is it still best to edit the files manually? I am having these same issues.

[samsafay]

This is not a SDK problem, the problem is on React-Native Android implementaion of XMLHttpRequest.
Off topic, based on personal experience, you are better off using react-native-firebase since it doesn't engage the Javascript thread; therefore a better performance.

[NickDelfino]

Yeah I am looking at that currently. Trying to keep everything in pure Expo but may not be possible right now. Some of the suggested spot fixes work but I am worried about downstream consequences. Are the PRs just in limbo right now? I hope they can get in soon.

Thanks for all your work in regards to this issue.

[samsafay]

Your welcome. Pure Expo, it might be possible in 2019 but not now!

[mikelehen]

Just to keep this updated, it looks like @samsafay's PR (facebook/react-native#17940) was committed on mar 6th (facebook/react-native@d52569c), and it should be included in the next react-native release... though I don't know when that'll be.

[samtstern]

@mikelehen is there any action left from our perspective or should we close this and point people over to react-native to watch the progress?

[mikelehen]

@samtstern No action for us... Folks can likely watch https://github.com/facebook/react-native/releases and wait for a release newer than the "February 2018" one. At that point, I believe the issue with Android not working should be fixed.

[i2chris]

@mikelehen thanks!!

[Luckygirlllll]

@dmitriy-bizyaev Where exactly in the project should I put that lines of the code which you wrote?

[dmitriy-bizyaev]

@Luckygirlllll Put it before your firebase.initializeApp() call.

[mikelehen]

FYI- The original issue with xhr.send() on Android that this bug was tracking has been resolved in the March React Native release (0.55.0).