lastResult.deref is not a function (it is undefined)

[quocluongha]

I updated to v5 and I encountered this error message when using createSelectorCreator with weakMapMemoize.

I returned a number in selectFormPosition and this error happened, but I tried to change the returned result into object then it is working fine.

The createDeepEqualSelector function:

export const createDeepEqualSelector = createSelectorCreator(weakMapMemoize, {
  resultEqualityCheck: isEqual, // lodash isEqual
});

The state:

const initialState = {
  formPosition: 0,
};

The selector functions:

export const selectWithdrawalState = (state: RootState) =>
  state.shopper.profile.withdrawal;

export const selectFormPosition = createDeepEqualSelector(
  selectWithdrawalState,
  state => state.formPosition,
  // state => ({ formPosition: state.formPosition }), <-- this is working fine

);

[aryaemami59]

I will take a look at this as soon as I get a chance, in the meantime if you remove the resaultEqualityCheck, the error should go away.

[quocluongha]

Thank you @aryaemami59, that is my temporary solution up to now.

[aryaemami59]

@quocluongha Just a quick question, are you using React Native or Expo?

[quocluongha]

@aryaemami59 I am using React Native 0.72.7

[aryaemami59]

@quocluongha Thank you, I'll put up a PR with the fix soon.

[EskiMojo14]

Fix released in v5.1.0