sos-nextjs/hooks/errorReducer.js

import {useReducer} from 'react'

const errorReducer = (errors, action) => {
  switch (action.type) {
    case 'set_errors':
      const newErrors = {}
      for(const field of action.errors)
        newErrors[field.param] = field.msg
      return newErrors

    case 'clear_error':
      console.log('clear_error', action)
      return {
        ...errors,
        [action.field]: undefined
      }

    default:
      return errors
  }
}

export default function useErrorReducer(initialState = {}){
  return useReducer( errorReducer )
}