person.ts

import { Record } from 'immutable'

interface PersonProps {
  firstName: string
  lastName: string
}

const defaultPersonProps: PersonProps = {
  firstName: '',
  lastName: '',
}

class Person extends Record(defaultPersonProps) implements PersonProps {
  public readonly firstName!: string
  public readonly lastName!: string

  public constructor(values?: Partial<PersonProps>) {
    values ? super(values) : super()
  }

  get fullName() {
    return `${this.firstName} ${this.lastName}`.trim()
  }
}

const jane = new Person({ firstName: 'Jane', lastName: 'Doe' })

console.log(`Hi, this is ${jane.fullName}!`)