import { v4 } from "react-native-uuid"; export default function subjects(state, action) { if (typeof state === "undefined") return []; switch(action.type) { case "ADD_SUBJECT": return [ ...state, { name: action.subject, id: v4() } ]; case "REMOVE_SUBJECT": return state.filter(item => item.id != action.id); default: return state; } }