react-native: Unhandled JS Exception: Unexpected token '{'. import call expects exactly one argument. no stack

I’m having the same issue after upgrading to RN 0.59.9. The error message gives basically no clue what’s wrong…

UPDATE

OK here is the digest of a few good hours spent:

In your index.js, there is something like this:

import { name as appName } from './app.json';
AppRegistry.registerComponent(appName, () => App);

Which import the name from app.json

{
  "name": "yourAppName",
  "displayName": "yourAppName"
}

To get rid of this error, just change index.js to:

AppRegistry.registerComponent('yourAppName', () => App);

and stop importing that json file.

You can keep all your present settings in devDependencies

Hey @steffi3rd, I suspect that there’s actually an issue in your project’s code. I think if you look at Metro, you’ll see a build-time error.

A few tips:

1. Try resetting all of the caches with:

 watchman watch-del-all && rm -rf $TMPDIR/react-native-packager-cache-* && rm -rf $TMPDIR/metro-bundler-cache-* && rm -rf node_modules/ && npm cache clean --force && npm install && npm start -- --reset-cache

1. Go ahead and upgrade to 0.59.1

Without a repository of your source, it’s hard to give specific advice. This seems like an environment issue, but please do follow up with more detail if my pointers above don’t help.

If this helps anyone I had the same issue and this helped me solve it. https://github.com/facebook/react-native/issues/21530#issuecomment-427577349

I fixed this problem by deleting the entire babel.config.js for the time being and letting react-native handle babel

Windows 10 - Android info React Native Environment Info: System: OS: Windows 10 CPU: (8) x64 Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz Memory: 1.19 GB / 7.91 GB Binaries: Node: 10.16.3 - C:\kafka\setting\node\node.EXE Yarn: 1.19.1 - C:\kafka\setting\yarn\bin\yarn.CMD npm: 6.9.0 - C:\kafka\setting\node\npm.CMD same issue

same issue

I had a similar issue with error Unhandled JS Exception: Unexpected identifier 'App'. import call expects exactly one argument. no stack

So the problem is apparently import App from './App';

I had several code blocks and reminders commented out above it, removing all these comments then the build is successful. So I suggest you to check your import methods.

Also, be careful when comment out code in RN in general, especially within render function. Hope it’s helpful.

I’m closing this issue since no repro was provided.

Upgrading to these versions seems to have fixed this issue for me on react-native v0.59.8

package.json

   "devDependencies": {
-    "@babel/core": "^7.4.4",
-    "@babel/runtime": "^7.4.4",
+    "@babel/core": "^7.4.5",
+    "@babel/runtime": "^7.4.5",
@@ -101,7 +101,7 @@
-    "metro-react-native-babel-preset": "^0.54.0",
+    "metro-react-native-babel-preset": "^0.54.1",

Got the same error. Renaming root index.js to index.ios.js did the trick for me. But I’m not sure what is the real issue here

Having the same issue… Cant see whats causing this nonsense… Metro running fine, everything compiles… Upon app launch this error comes up with no indication… Nothing in the console either…

Thanks for your anwser, I did this :

watchman watch-del-all && rm -rf $TMPDIR/react-native-packager-cache-* && rm -rf $TMPDIR/metro-bundler-cache-* && rm -rf node_modules/ && npm cache clean --force && npm install && npm start -- --reset-cache

Now the error has changed but similar. I don’t any details on “Extra Info”

• It works very well on Simulator.
• Metro bundler is build fine
• Xcode project build success

Seems like a error in your code. Can you provide a screenshot of console with Debug JS Remotely?

Can you provide a minimal reproducible example for this? That would help us narrow down the issue better.