React-native: RN 0.60 Hermes: Property 'Proxy' doesn't exist.

[arivanandan]

RN: v0.60.4

Been upgrading this project from 0.53. Please let me know what could be causing this so I could follow up with code snippets of relevant files.

It goes away when I turn off hermes.

I also see this when the app is loading:
couldn't find DSO to load: libjscexecutor.so

[react-native-bot]

Thanks for submitting your issue. Can you take another look at your description and make sure the issue template has been filled in its entirety?

👉 Click here if you want to take another look at the Bug Report issue template.

[ecreeth]

@arivanandan Please, make sure that the update of your project has been correct in the following link

[guhungry]

I think it's because Hermes engine doesn't support Proxy https://github.com/facebook/hermes/issues/28

[arivanandan]

I have been using the rn-upgrade-helper and it's been very helpful!

So, if Proxy isn't present can I add a polyfill or should I just leave hermes off?

[guhungry]

I would suggest turn hermes off.
Proxy is low level API which can't be polyfilled completely and efficiently. But you can try https://github.com/GoogleChrome/proxy-polyfill

[arivanandan]

I tried it and it doesn't seem to work. Seems like we have to wait for hermes to support it (if at all).

[jp928]

@arivanandan

Add

project.ext.react = [
        root           : "../../../",
        entryFile      : "index.js",
        bundleAssetName: "index.bundle",
        enableHermes   : true,
        bundleInAlpha  : true,
        bundleInBeta   : true,
        hermesFlagsDebug:['-Xes6-proxy'],
        hermesFlagsRelease:['-Xes6-proxy']
]

in build.gradle

here is an example:
https://github.com/wix/react-native-notifications/blob/master/example/android/myapplication/build.gradle