React Native, iOS: "Can't find variable: Image"

[ghost]

Unhandled JS Exception: Can't find variable: Image

I get this message when I run a transaction on the iOS Simulator offline:

const ok = await db.runTransaction(async (t) => {
    t.set(docRef, data);
    return true;
});

It retries the transaction around 3-5 times over around 2 minutes, then throws the Exception.

I am using the Xcode "Network Link Conditioner" to disable the network.

Related
#183

Environment

• iOS Simulator
• MacOS,
• RN: 0.55.3
• Firebase (from yarn.lock):

firebase@^5.5.2:
  resolved "https://registry.yarnpkg.com/firebase/-/firebase-5.5.2.tgz#05fa180c058941dcbfc248882e829f2945aa0568"
    "@firebase/app" "0.3.4"
    "@firebase/auth" "0.7.7"
    "@firebase/database" "0.3.6"
    "@firebase/firestore" "0.8.2"
    "@firebase/functions" "0.3.1"
    "@firebase/messaging" "0.3.6"
    "@firebase/polyfill" "0.3.3"
    "@firebase/storage" "0.2.3"

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[mikelehen]

Ahh, interesting! runTransaction hits a different mechanism for sending network requests, so I guess that's why you are hitting this even though #183 was fixed.

It's worth noting that transactions do not work offline. They are expected to fail, though not via a "Unhandled JS Exception". :-) So This sounds like a bug, but you may want to revisit using transactions if you want that code to work while offline.

[mikelehen]

Do you by chance get callstack with that error? Offhand I'm having trouble tracking down where it's coming from. Or if you can throw a project on github that reproduces the problem, that would help.

[ghost]

The Exception also throws when not using runTransaction.

It's worth noting that transactions do not work offline

That is the reason I am using runTransaction - I want to get a fail message in response.

Because there are no timeouts or cancellations for Promises, the normal await docRef.set(data) does not resolve when offline.

The runTransaction API gives a failed Promise after a certain amount of time.

I also want to avoid using the local cache, which the Firestore APIs seem to use unpredictably even when its turned off via settings.

It would be good to have a {source: "server"} option for writes and onSnapshot (it exists for reads).

The react-native-firebase library also has critical bugs.

Do you think Im better off just using the HTTP API directly?

I could not get a proper stack trace from React Native. This is from Chrome, Im not sure if there is a better way?

[mikelehen]

Hrm, yeah, if you don't want caching or offline support, then the REST API may be a better option for you. Though I don't think it supports realtime listens (as onSnapshot() provides), so if you're using that, it may not be a perfect fit. :-/

[fredrivett]

I'm getting a similar issue, first bug report came in on Oct 17th 2018.

I'm not trying to access any images in Firebase which is what's confusing me about this error. Using the Firebase npm package (https://www.npmjs.com/package/firebase) to access our Firestore DB.

Sentry error report:

[Danelund]

@fredrivett did you resolve? I'm seeing the same thing

[fredrivett]

@Danelund no that error still persists for me. We're now actually looking to move away from Firebase to AWS, so haven't investigated much further. Are you on the latest version of the firebase-js-sdk? That's the next port of call I'm going to check, upgrade that and check back in. If you end up upgrading I'd be interested to hear if that fixes the issue.

[Danelund]

@fredrivett just upgraded to 5.7.0, seems to be working so far, but will have sentry report in from users :)

[fredrivett]

@Danelund thanks for looping back. Did this fix it for you? We haven't got round to upgrading yet (I know), but be intrigued if it cleared things up your end.

[Danelund]

@fredrivett nope - still getting it

[fredrivett]

@Danelund Hmmph. Super strange issue this. Does seem to be coming from Firebase but clearly not affecting everyone using the SDK in React Native as otherwise this thread would be flooded.

[mikelehen]

Sorry for the delays. I poked at this, and I have a hunch that the issue we're hitting is this new Image() call in webchannel (one of our dependencies). I've reached out to a dev on the team to see if we can get this resolved.

[fredrivett]

No worries @mikelehen. Appreciate you taking a look.

[mikelehen]

Internal tracking issue: b/123242479

[Huzaifaak]

I am getting this issue with "firebase": "^5.7.3". Maybe you can track this issue with this screenshot:

[wilhuff]

@mikelehen FYI, the required webchannel fix has made it out to public webchannel.

[mikelehen]

@wilhuff Thanks. I just checked and we picked up this change in 4983420 so the issue should actually be resolved in the latest release.

Please holler if anybody is still running into this.

[cawfree]

Simple workaround:

console.error = console.log;