options_functional.ts

type Material = 'wood' | 'brick' | 'steel'

type HouseOption = (h: House) => void

class House {
  private rooms: number
  private floors: number
  private material: Material

  constructor(...options: HouseOption[]) {
    // defaults are clear
    this.rooms = 1
    this.floors = 1
    this.material = 'wood'
    
    // set the options
    for (const option of options) {
      option(this)
    }
  }

  public static WithRooms(roomCount: number): HouseOption {
    if (roomCount < 1) {
      throw new Error('a House can not have less than 1 room!')
    }
    return (h: House): void => {
      h.rooms = roomCount
    }
  }

  public static WithFloors(floorCount: number): HouseOption {
    if (floorCount < 1) {
      throw new Error('a House can not have less than 1 floor!')
    }
    return (h: House): void => {
      h.floors = floorCount
    }
  }

  public static WithMaterial(material: Material): HouseOption {
    return (h: House): void => {
      h.material = material
    }
  }
}

construction:

const myHouse = new House(
  House.WithRooms(5),
  House.WithFloors(2),
  House.WithMaterial('wood')
)