Redefining our models

Grocery list

import type { Branded } from '…'

export interface GroceryList {
  id: ListId
  name: ListName
  archiveDate: Date | undefined
  items: Map<ItemName, ItemQuantity>
  memberIds: Set<MemberId>
}

export type ListId = Branded<string, 'ListId'>
export type ListName = Branded<string, 'ListName'>
export type ItemName = Branded<string, 'ItemName'>
export type ItemQuantity = Branded<number, 'ItemQuantity'>

Member

import type { Branded } from '…'

export interface Member {
  id: MemberId
  name: MemberName
}
export type MemberId = Branded<string, 'MemberId'>
export type MemberName = Branded<string, 'MemberName'>

Domain-Driven Design Definitions

TIP

DDD definitions: If you crossed the concepts of "value object" and "entity" and did not get the difference, here it is:

1. Value objects: ListName, ItemName, ItemQuantity… -> 2 list names are equal if their values are equal. ListName "toto" === ListName "toto".
2. Entities: GroceryList, Member. -> 2 members are identical if their memberId is the same. Entities have cycles, they evolve over time.