Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.

[sofianegargouri]

Environment

Environment:
OS: macOS High Sierra 10.13.5
Node: 10.5.0
Yarn: 1.5.1
npm: Not Found
Watchman: 4.9.0
Xcode: Xcode 9.1 Build version 9B55
Android Studio: 2.3 AI-162.4069837

Packages: (wanted => installed)
react: 16.3.1 => 16.3.1
react-native: ~0.55.2 => 0.55.4

Description

Hi ! 👋
I initiated a new project with Expo, everything was working fine, but since I ejected it, I can't get rid of that error:

Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.

I have a little bit of experience with React Native but I can't put my finger on the problem here.

Reproducible Demo

Initiate a project with Expo
Eject it

/index.js:

import { AppRegistry } from 'react-native'
import App from './app'

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

/app/index.js:

import React from 'react'
import { Text, View } from 'react-native'

export default () => (
  <View>
    <Text>Test</Text>
  </View>
)

And here is the error:

Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.

This error is located at:
    in RCTView (at View.js:60)
    in View (at AppContainer.js:102)
    in RCTView (at View.js:60)
    in View (at AppContainer.js:122)
    in AppContainer (at renderApplication.js:32)
throwOnInvalidElementType
    ReactNativeRenderer-dev.js:4706:4
createFiberFromElement
    ReactNativeRenderer-dev.js:4663:42
reconcileSingleElement
    ReactNativeRenderer-dev.js:8338:8
reconcileChildFibers
    ReactNativeRenderer-dev.js:8422:14
reconcileChildrenAtExpirationTime
    ReactNativeRenderer-dev.js:8622:8
reconcileChildren
    ReactNativeRenderer-dev.js:8603:6
updateHostComponent
    ReactNativeRenderer-dev.js:9001:22
beginWork
    ReactNativeRenderer-dev.js:9589:10
performUnitOfWork
    ReactNativeRenderer-dev.js:12924:25
workLoop
    ReactNativeRenderer-dev.js:12953:43
renderRoot
    ReactNativeRenderer-dev.js:12996:17
performWorkOnRoot
    ReactNativeRenderer-dev.js:13632:34
performWork
    ReactNativeRenderer-dev.js:13545:26
performSyncWork
    ReactNativeRenderer-dev.js:13506:16
requestWork
    ReactNativeRenderer-dev.js:13392:6
scheduleWorkImpl
    ReactNativeRenderer-dev.js:13259:24
scheduleWork
    ReactNativeRenderer-dev.js:13207:28
scheduleRootUpdate
    ReactNativeRenderer-dev.js:13930:17
_updateContainerAtExpirationTime
    ReactNativeRenderer-dev.js:13966:6
updateContainer
    ReactNativeRenderer-dev.js:13991:8
render
    ReactNativeRenderer-dev.js:14726:35
renderApplication
    renderApplication.js:49:21
run
    AppRegistry.js:102:10
runApplication
    AppRegistry.js:194:26
__callFunction
    MessageQueue.js:351:47
<unknown>
    MessageQueue.js:116:26
__guardSafe
    MessageQueue.js:314:6
callFunctionReturnFlushedQueue
    MessageQueue.js:115:17

[sofianegargouri]

Found the issue:

import App from './app' is importing /app.json instead of the index of my /app folder.

app.json is containing the following, probably some rest from Expo:

{
  "expo": {
    "sdkVersion": "27.0.0"
  },
  "name": "MyApp",
  "displayName": "MyApp"
}

[oskaryil]

@sofianegargouri Thanks.. This had me going crazy.. Such a small unnoticable thing too.