Entity adapter getSelectors method generates "Cannot read property 'map' of undefined" error

Question

I am trying to use createEntityAdapter from reduxjs/toolkit to generate selectors automatically.

I have created a "select all" selector successfully using create selector:

export const selectEnvironmentsResult = extendedApiSlice.endpoints.getEnvironments.select()

export const selectAllEnvironments = createSelector(
  selectEnvironmentsResult,
  environmentsResult => environmentsResult?.data ?? []
)

And works fine:

const data = useSelector(selectAllEnvironments) // data is correctly defined :)

But, when I try to use createEntityAdapter to create the selectors:

export const selectEnvironmentsResult = extendedApiSlice.endpoints.getEnvironments.select()

export const selectAllEnvironments = createSelector(
  selectEnvironmentsResult,
  environmentsResult => environmentsResult?.data ?? []
)


export const {
  selectAll,
  selectById,
  selectIds,
} = environmentsAdapter.getSelectors((state) => {
    const selected = selectAllEnvironments(state) ?? initialState
    console.log( selected ) // prints "[]"
    return selected
  }
)

and use it, I get an error:

const data = useSelector(selectAll) // Uncaught TypeError: Cannot read property 'map' of undefined

Answer 1

The error was in the transformReponse value. You should use the adapter.setAll function:

      transformResponse: (responseData) => {
        return adapter.setAll(adapter.getInitialState(), responseData)
      },