A Redux example

Redux example.js

const store = {
  partyMembers: []
}

const addPersonToParty = (person) => ({type: "ADD_PERSON_TO_PARTY", payload: person})
const removePersonFromParty = (person) => ({type: "REMOVE_PERSON_FROM_PARTY", payload: person})

const reducer = (state = store, action) => {
  switch (action.type) {
    case "ADD_PERSON_TO_PARTY":
      return { partyMembers: [...state.partyMembers, action.payload] }
    case "REMOVE_PERSON_FROM_PARTY":
      return { partyMembers: state.partyMember.filter(member => member.toUpperCase() !== action.payload.toUpperCase()) }
    default:
      return state
  }
}