React-native-firebase: Hermes

[Bardiamist]

[Update in September, 2020: Hermes released 0.7 which contains Proxy support, which is needed by @react-native-firebase/database so it may all work now, test carefully though!]

Documentation Feedback

It works with Hermes now?

At this time, React Native Firebase does not support the Hermes JavaScript engine due to compatibility issues. We are actively tracking the changes to Hermes and will ensure support once both are compatible with each other.

I see this in documentation but not found any related issue/discussion.

[Ehesp]

We haven't tried it in a little while, but it was missing a core feature last time we checked causing issues.

If anyone would like to try with the latest version please do.

[Bardiamist]

it was missing a core feature

What is core feature? Something from this list?

last time we checked causing issues

What issues? It doesn't fully work? Or worked with some bugs?

I use Hermes and want mirgate react-native-firebase from v5 to v6. I need to understand how v6 stable with Hermes.

[Ehesp]

What is core feature? Something from this list ?

Yep.

What issues? It doesn't fully work? Or worked with some bugs?

Didn't even work. Like I said, we need to review it again.

[loverdeveloper]

is v5 support Hermes?

[mikehardy]

@loverdeveloper doubtful, only way to know though is to try it, then test your entire app on all target devices.

[Bardiamist]

@loverdeveloper I use v5 only for push notifications, no problems were noticed.

[loverdeveloper]

it's not enough for me, i want to use analytics, crashlyrics and etc

[bell-steven]

I've been using v5 with hermes without any issues. Analytics, Auth and Messaging.

[comvenger-brandon]

Working for us without any problems. v6: Analytics, Messaging, Crashlytics, Dynamic Links, Performance.

[loverdeveloper]

@comvenger-brandon
How? I switched engine to Hermes and then my events not work, i think my screen views works but events not, i can't see them in firebase stream view!
Do you do something special?

[comvenger-brandon]

@comvenger-brandon
How? I switched engine to Hermes and then my events not work, i think my screen views works but events not, i can't see them in firebase stream view!
Do you do something special?

RN 0.62.2, hermes 0.4.1, RNF 6.4.0.
No special config, just the regular installation.

[loverdeveloper]

@comvenger-brandon Thanks man, i will try it

[loverdeveloper]

@comvenger-brandon Do you testing on android? Or IOS?

[loverdeveloper]

Guys, after updating RN to 62, it works :) I'm so happy

[billel-boudchicha]

guys , doesn't work , no events , no notifications
"@react-native-firebase/app": "^7.0.0",
"@react-native-firebase/messaging": "^7.0.0",
"react-native": "0.62.2"
Android

[RuairiOliver]

Fine for me with hermes enabled on v6:

"@react-native-firebase/analytics": "^6.3.4",
"@react-native-firebase/app": "^6.3.4",
"@react-native-firebase/crashlytics": "^6.3.4",
"@react-native-firebase/dynamic-links": "^6.3.4",
"@react-native-firebase/messaging": "^6.3.4",
"@react-native-firebase/ml-vision": "^6.3.4",

[haswalt]

So ^6 works but ^7 doesn't?

[joshlbaker]

Hermes works with these two for me:

    "@react-native-firebase/app": "^6.7.1",
    "@react-native-firebase/messaging": "^6.7.1",

Someone should really update those docs. The default shouldn't be to disable Hermes

[Bardiamist]

I use

"react-native": "0.62.2",
"@react-native-firebase/app": "7.1.0",
"@react-native-firebase/messaging": "7.1.0",

looks good

[haswalt]

Thanks @joshlbaker @Bardiamist much appreciated

[joshlbaker]

Oh yeah I'm on "react-native": "0.62.2" as well

[chungweileong94]

Apparently, I faced an error while I try to push data to the realtime database, and it was working fine with Hermes disabled.

I'm getting [ReferenceError: Property 'Proxy' doesn't exist], so for realtime database, we might have to wait for Hermes to support it then.

I'm on react-native 0.62 & react-native-firebase 6.7.1

[Bardiamist]

I think Hermes will not support Proxy. Better if react-native-firebase will not use Proxy.

[mikehardy]

If Hermes is supposed to be a full fledged javascript implementation, shouldn't that read "better if hermes will support proxy"? Behold, it is possible, if anyone wants to try it: https://github.com/facebook/hermes/issues/33#issuecomment-606963341

[SudoPlz]

Looks like Hermes works on our end (react-native 0.63) without making any changes at all.

We're not using any firebase database at all, which looks like it's the only thing using Proxy and thus blocking Hermes so far.

Long story short, if you're not using databases from firebase you can probably enable Hermes

[Salakar]

@SudoPlz This is correct. Hermes should generally work, was just edge cases like Proxy in DB that were blocking. I believe Proxy support has landed in Hermes now (as @mikehardy mentioned above) but the version shipped with RN hasn't been updated yet (last checked RN 0.63). So it's just a matter of time, that or a PR would be welcome to remove proxy usage from DB :)

[deepakverma4]

@Salakar I am not able to use firebase database with hermes enabled. Any workaround to use firebase database with hermes enabled?

[chungweileong94]

@Salakar I am not able to use firebase database with hermes enabled. Any workaround to use firebase database with hermes enabled?

I'm not sure if this help, but someone actually using a polyfill to work around this issue. https://github.com/facebook/hermes/issues/33#issuecomment-664403786

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[Lucas-Geitner]

Hello :^)

Hermes just released his version 0.7, with Proxy support by default 🚀

👉🏻 https://github.com/facebook/hermes/releases/tag/v0.7.0

[mikehardy]

@Lucas-Geitner do you confirm that it works with hermes? Including @react-native-firebase/database? If so, you could propose a docs PR that upgrades our Hermes-related documentation from a sort of "warning: don't use" to a "we think this should work now but test it carefully in your project to make sure" ?

[oguzhanali]

I tried it on RN 63 Hermes enabled Android with Auth, Firestore and Messaging and it seems everything works fine.

[leelandclay]

I just updated to RN 0.63. It still uses version 0.5 of hermes and does not work with Database.
Has there been any mention from the react-native team if they're going to update the dependencies any time soon?

[Bardiamist]

@leelandclay React native 0.64.0 will suport Hermes with Proxy (read as react-native-firebase database)

[leelandclay]

@Bardiamist thanks. I totally missed the 64 part.