DataStore + Hermes = 💩 ([TypeError: Symbol.asyncIterator is not defined.])

[Darapsas]

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• [X] I have searched for duplicate or closed issues and discussions.
• [X] I have read the guide for submitting bug reports.
• [X] I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.

JavaScript Framework

React Native

Amplify APIs

DataStore

Amplify Categories

auth, api

Environment information

``` # Put output below this line System: OS: macOS 10.15.7 CPU: (6) x64 Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz Memory: 647.25 MB / 16.00 GB Shell: 5.7.1 - /bin/zsh Binaries: Node: 16.0.0 - /usr/local/bin/node Yarn: 1.22.10 - /usr/local/bin/yarn npm: 7.10.0 - /usr/local/bin/npm Watchman: 4.9.0 - /usr/local/bin/watchman Browsers: Chrome: 88.0.4324.96 Firefox: 88.0 Safari: 14.0.3 npmPackages: @babel/core: ^7.12.9 => 7.13.16 (7.9.0) @babel/runtime: ^7.12.5 => 7.13.17 @react-native-async-storage/async-storage: ^1.15.3 => 1.15.3 @react-native-community/blur: ^3.6.0 => 3.6.0 @react-native-community/eslint-config: ^2.0.0 => 2.0.0 @react-native-community/geolocation: ^2.0.2 => 2.0.2 @react-native-community/masked-view: 0.1.10 => 0.1.10 @react-native-community/netinfo: ^6.0.0 => 6.0.0 @react-navigation/bottom-tabs: 5.11.9 => 5.11.9 @react-navigation/native: 5.9.4 => 5.9.4 @react-navigation/stack: 5.14.4 => 5.14.4 @svgr/cli: 5.5.0 => 5.5.0 @testing-library/jest-native: ^3.4.3 => 3.4.3 @testing-library/react-native: ^7.0.2 => 7.2.0 @types/color: ^3.0.1 => 3.0.1 @types/i18n-js: ^3.8.0 => 3.8.0 @types/jest: ^26.0.22 => 26.0.22 @types/lodash: ^4.14.168 => 4.14.168 @types/react: ^17.0.3 => 17.0.3 @types/react-native: ^0.64.2 => 0.64.4 @types/react-native-vector-icons: 6.4.6 => 6.4.6 @types/react-test-renderer: ^17.0.1 => 17.0.1 @types/yup: ^0.29.0 => 0.29.11 HelloWorld: 0.0.1 amazon-cognito-identity-js: 4.6.0 => 4.6.0 aws-amplify: 3.3.27 => 3.3.27 babel-jest: ^26.6.3 => 26.6.3 color: 3.1.3 => 3.1.3 eslint: 7.14.0 => 7.14.0 expo-image-picker: ^10.0.0 => 10.1.4 expo-localization: ^10.0.0 => 10.1.0 expo-location: ^11.0.0 => 11.0.0 expo-payments-stripe: ^9.0.0 => 9.2.3 expo-splash-screen: ^0.9.0 => 0.9.0 formik: 2.2.4 => 2.2.4 hermes-inspector-msggen: 1.0.0 i18n-js: ^3.8.0 => 3.8.0 inquirer: 8.0.0 => 8.0.0 jest: ^26.6.3 => 26.6.3 libphonenumber-js: 1.9.16 => 1.9.16 libphonenumber-js-core: 1.0.0 libphonenumber-js-max: 1.0.0 libphonenumber-js-min: 1.0.0 libphonenumber-js-mobile: 1.0.0 lodash: ^4.17.21 => 4.17.21 metro-react-native-babel-preset: ^0.64.0 => 0.64.0 prettier: 2.2.1 => 2.2.1 react: 17.0.1 => 17.0.1 react-native: 0.64.0 => 0.64.0 react-native-animated-spinkit: ^1.5.2 => 1.5.2 react-native-calendars: 1.1255.0 => 1.1255.0 react-native-confirmation-code-field: ^7.0.1 => 7.0.1 react-native-device-info: ^8.0.8 => 8.1.2 react-native-geolocation-service: 5.2.0 => 5.2.0 react-native-gesture-handler: ^1.10.3 => 1.10.3 react-native-google-places-autocomplete: 2.2.0 => 2.2.0 react-native-maps: ^0.28.0 => 0.28.0 react-native-paper: ^4.7.2 => 4.8.0 react-native-reanimated: 2.0.1 => 2.0.1 react-native-safe-area-context: 3.2.0 => 3.2.0 react-native-screens: 3.1.0 => 3.1.0 react-native-status-bar-height: ^2.6.0 => 2.6.0 react-native-svg: 12.1.0 => 12.1.0 react-native-unimodules: ^0.12.0 => 0.12.0 react-native-vector-icons: ^8.1.0 => 8.1.0 react-test-renderer: 17.0.1 => 17.0.1 ts-jest: ^26.5.4 => 26.5.5 ts-node: ^9.1.1 => 9.1.1 typescript: 3.8.3 => 3.8.3 world-countries: 4.0.0 => 4.0.0 yup: 0.32.9 => 0.32.9 npmGlobalPackages: @aws-amplify/cli: 4.48.0 npm: 7.10.0 ```

Describe the bug

When trying to start DataStore with DataStore.query(...), I get [TypeError: Symbol.asyncIterator is not defined.]. It appears only when I try to enable hermes js engine, otherwise, it seems to work properly.

Expected behavior

I expect it to work

Reproduction steps

Enable hermes in iOS or Android, on a bare React native application and try to start DataStore.

Code Snippet

// Put your code below this line.
  const startDataStore = async () => {
    try {
      console.log(`DATASTORE - starting`)
      const user = await Auth.currentUserInfo()
      //await DataStore.start()
      await DataStore.query(UserData, u => u.owner('eq', user.username))
    } catch (err) {
      console.log(`DATASTORE - error`)
      console.log(err)
      console.log('-----------------')
    }
  }

Log output

``` // Put your logs below this line LOG DATASTORE - starting LOG DATASTORE - error LOG [TypeError: Symbol.asyncIterator is not defined.] LOG {} LOG ----------------- ```

aws-exports.js

No response

Manual configuration

No response

Additional configuration

No response

Mobile Device

No response

Mobile Operating System

No response

Mobile Browser

No response

Mobile Browser Version

No response

Additional information and screenshots

No response

[manueliglesias]

Hi @Darapsas

I did a quick search on hermes repo and found facebook/hermes#227

Can you try the suggestions in there? (mainly providing a polyfill)

[Darapsas]

Hello @manueliglesias, thank you again for showing my braindeadiness, saw that post, installed the package, but forgot to import it and of course, didn't take it too seriously, because of the age it had... Anyhow, if any of you get this error, just do this:

npm install @azure/core-asynciterator-polyfill

or

yarn add @azure/core-asynciterator-polyfill

and most importantly do not forget to import the package before any other imports in your index.js file:

import '@azure/core-asynciterator-polyfill'

Clean rebuild your project and you should be good to go.

Kudos to the original answer writer @mhorowitz

[moob123]

I have the same issue, I just noticed it is on the anniversary of this ticket :)

[chrisbonifacio]

@moob123 did the polyfill still work for you a year later?

[moob123]

Yes, happy :) the info was much appreciated. Although somewhat amused, how is this not some basic issue for others, so that it is still not solved?

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