React Native, Expo support? Throw Error: "s" is read-only

[igsys]

Nice library! I am using this in an Expo project (SDK37), it gives me _readOnlyError. I thought I did something wrong with my code, and used the example from document, and output the same errors when I use 'selector' as an argument in useRecoilState. Notice, 'atom' does not throw errors, working fine.

Any solution to this?

import {
  Text,
  Button,
  View,
} from 'react-native'
import { atom, selector, useRecoilState } from 'recoil'

const tempFahrenheit = atom({
  key: 'tempFahrenheit',
  default: 32,
})

const tempCelcius = selector({
  key: 'tempCelcius',
  get: ({ get }) => ((get(tempFahrenheit) - 32) * 5) / 9,
  set: ({ set }, newValue) => set(tempFahrenheit, (newValue * 9) / 5 + 32),
})

const TempCelcius = () => {
  const [tempF, setTempF] = useRecoilState(tempFahrenheit)
  const [tempC, setTempC] = useRecoilState(tempCelcius)

  const addTenCelcius = () => setTempC(tempC + 10)
  const addTenFahrenheit = () => setTempF(tempF + 10)

  return (
    <View>
      <Text>Temp (Celcius): {tempC}</Text>
      <Text>Text>Temp (Fahrenheit): {tempF}</Text>
      <Button
        title='Add 10 Celcius'
        onPress={addTenCelcius} />
      <Button
        title='Add 10 Fahrenheit'
        onPress={addTenFahrenheit}
      />
    </View>
  )
}

export {
  TempCelcius,
}
export default TempCelcius

Error

Error: "s" is read-only

_readOnlyError
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:147369:20
c
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:147190:42
<unknown>
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:147195:24
<unknown>
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:147216:10
i
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:147250:8
<unknown>
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:146334:21
replaceState
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:146567:20
getRecoilValueAsLoadable
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:146332:21
r
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:146808:12
getRecoilState
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:146815:20
useRecoilState
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:146905:47
renderWithHooks
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:20048:33
mountIndeterminateComponent
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:22097:34
beginWork$$1
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:27288:31
performUnitOfWork
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:26441:30
workLoopSync
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:26423:45
renderRoot
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:26187:29
renderRoot
    [native code]:0
runRootCallback
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:25948:34
runRootCallback
    [native code]:0
<unknown>
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:16678:38
unstable_runWithPriority
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:43144:30
flushSyncCallbackQueueImpl
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:16673:28
flushSyncCallbackQueue
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:16662:35
scheduleUpdateOnFiber
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:25830:37
scheduleRootUpdate
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:28255:21
scheduleRoot
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:17226:42
<unknown>
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:41547:35
forEach
    [native code]:0
performReactRefresh
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:41539:30
performReactRefresh
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:41345:48
<unknown>
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:480:40
_callTimer
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:31051:17
callTimers
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:31258:19
__callFunction
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:3225:49
<unknown>
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:2938:31
__guard
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:3179:15
callFunctionReturnFlushedQueue
    AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:2937:21
callFunctionReturnFlushedQueue
    [native code]:0

[suhaotian]

The hooks write with react-dom, https://github.com/facebookexperimental/Recoil/blob/master/src/hooks/Recoil_Hooks.js#L24

That means the library didn't support react-native yet

[ghidoras]

hm. I somehow have this error in a web app, not react-native.

[ghidoras]

in my case the selector fails on get(manuscriptAtom);

export const journalNameAtom = selector({
  key: 'journalName',
  get({ get }) {
    const manuscript: Manuscript = get(manuscriptAtom);
    return manuscript?.journal?.name ?? '';
  },
});

tried to get rid of

alias: {
  'react-dom': '@hot-loader/react-dom',
},

from webpack config and still nothing. Using version 0.0.7

[ralphievolt]

same error here in react-native... i wonder how difficult is it to implement in react native

[Naturalclar]

I'm thinking if somehow we can replace the usage of react-dom with react-reconciler, we can use recoil with react-native projects. I've looked at it a little, but it doesn't seem like a simple replacement that can be done with codemod. I'd have to look into it further.

[Robert187]

Yeah I have that same problem on one my phone s

[Robert187]

I'll have to look into it I can revoke it butt Im not sure if you want that

[jacques-blom]

It's working for me when I link it locally and build it without terser (minification). Here's my Expo project if anyone wants to see how to get linking working: https://github.com/jacques-blom/recoil-test-expo

Check out the Readme for setup instructions.

Looking into why terser is causing this.

[jacques-blom]

[jacques-blom]

Here's a PR that aims to fix this: https://github.com/facebookexperimental/Recoil/pull/69

[davidmccabe]

Thanks for reporting and for the fix!