syntax 'nullishCoalescingOperator' isn't currently enabled

Question

when I tried to build my app on ios-simulator it says :

bundling failed: SyntaxError: /Users/MyName/MyApp/node_modules/react-native/node_modules/react-native/Libraries/Components/Switch/Switch.js: Support for the experimental syntax nullishCoalescingOperator isn't currently enabled (167:52):

 165 |         {...props}
  166 |         {...platformProps}
> 167 |         accessibilityRole={props.accessibilityRole ?? 'button'}
      |                                                    ^
  168 |         onChange={this._handleChange}
  169 |         onResponderTerminationRequest={returnsFalse}
  170 |         onStartShouldSetResponder={returnsTrue}

Add @babel/plugin-proposal-nullish-coalescing-operator (https://git.io/vb4Se) to the 'plugins' section of your Babel config to enable transformation.

I did what it says, but it just didn't help... Any help will be appreciated.

Javascript doesn't have the `Nullish Coalescing` operator right now, the proposal for `Nullish Coalescing` proposal is at stage-1 in TC39. — Mostafiz Rahman, Dec 27 '18 at 11:36

Mahgolsadat Fathi · Accepted Answer · 2019-02-25T14:05:24.407

32

I think it resolved by changing my .babelrc to

{
  "presets": ["module:metro-react-native-babel-preset"]
}

this change is caused by upgrading my react-native version

edited Feb 25 '19 at 14:05

answered Dec 29 '18 at 07:33

Mahgolsadat Fathi

3,107
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getting _this._registerevents is not a function thios error when I used it – Samiksha Jagtap Feb 05 '19 at 10:28
@SamikshaJagtap ok that is an other problem, follow my answer on https://stackoverflow.com/questions/52713101/undefined-is-not-a-function-evaluating-this-registerevents/54021606#54021606 – Mahgolsadat Fathi Feb 06 '19 at 14:58
yes, i was able to fix with this just needed to fix some version dependency – Samiksha Jagtap Feb 08 '19 at 13:37
I am still unable to resolve this issue. Also tried adding '@babel/plugin-proposal-nullish-coalescing-operator' as a plugin. – akshay gore May 13 '19 at 21:48
@akshaygore did you try upgrading your react-native version ? – Mahgolsadat Fathi May 14 '19 at 12:46
1

@MahgolFa My app was not using the correct .babelrc. Its working fine now. Thanks – akshay gore May 14 '19 at 22:15

syntax 'nullishCoalescingOperator' isn't currently enabled

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