manyUsers.json

{
  "data": [
    {
      "id": "123456789",
      "name": "Person A",
      "username": "PersonA"
    },
    {
      "id": "987654321",
      "name": "Person B",
      "username": "PersonB"
    },
  ],
  "includes": {
    "tweets": [
      {
        "id": "12345678",
        "text": "Example text"
      }
    ]
  }
}

singleUser.json

{
  "data": {
    "id": "123456789",
    "name": "Person A",
    "username": "PersonA"
  },
  "includes": {
    "tweets": [
      {
        "id": "12345678",
        "text": "Example text"
      }
    ]
  }
}

User.swift

struct User: Codable, Identifiable {
  typealias ID = String
  let id: ID
  let name: String
  let username: String

  // Assume that items can be optionally set in getUser
  var items: UserItems?
}

struct UserItems: Codable {
  let tweets: [Tweet]
}

struct ManyUsers: Codable {
  let data: [User]
  var items: UserItems?
}

protocol APIProvider {
  // Option A
  // Tuple type for cases with many users
  func getUser(id: User.ID) async -> User
  func getUsers(ids: [User.ID]) async -> ([User], UserItems?)

  // Option B
  // A separate struct type for many users
  // func getUser... (as above)
  func getUsers(ids: [User.ID]) async -> ManyUsers

  // Option C
  // Just ignore expanded items
  // func getUser... (as above)
  func getUsers(ids: [User.ID]) async -> [User]


}

API nerds, I could use some help! The Twitter v2 API lets you optionally expand fields on users (namely pinned tweets). These expansions end up in the includes field on the returned JSON.

It’s easy enough to set those items on a User struct when calling the API for a single user, but when calling multiple users, it’s hard to keep a decent mapping between each user in the data field and their respective tweets in the includes field.