import { shallowEqual } from 'react-redux' import { createSelector, lruMemoize } from 'reselect' export interface RootState { todos: { id: number completed: boolean title: string description: string }[] alerts: { id: number; read: boolean }[] } const selectTodoIds = createSelector( [(state: RootState) => state.todos], todos => todos.map(todo => todo.id), { memoize: lruMemoize, memoizeOptions: { equalityCheck: shallowEqual, resultEqualityCheck: shallowEqual, maxSize: 10 }, argsMemoize: lruMemoize, argsMemoizeOptions: { equalityCheck: shallowEqual, resultEqualityCheck: shallowEqual, maxSize: 10 } } )