Entities & Value Objects

1// Entity — identité via l'ID
2abstract class Entity<T> {
3  protected readonly _id: T;
4
5  constructor(id: T) {
6    this._id = id;
7  }
8
9  get id(): T { return this._id; }
10
11  // Égalité basée sur l'ID
12  equals(other: Entity<T>): boolean {
13    return this._id === other._id;
14  }
15}
16
17// Entité User — son identité est son ID
18class User extends Entity<string> {
19  private _email: Email;        // Value Object
20  private _name: FullName;      // Value Object
21  private _role: UserRole;
22  private _events: DomainEvent[] = [];
23
24  private constructor(
25    id: string,
26    email: Email,
27    name: FullName,
28    role: UserRole,
29  ) {
30    super(id);
31    this._email = email;
32    this._name = name;
33    this._role = role;
34  }
35
36  // Factory method — validation dans la création
37  static create(props: CreateUserProps): User {
38    const id = generateId();
39    const email = Email.create(props.email);   // peut lancer une erreur
40    const name = FullName.create(props.firstName, props.lastName);
41    return new User(id, email, name, 'viewer');
42  }
43
44  // Reconstitution depuis la persistence (pas de validation re-exécutée)
45  static reconstitute(data: UserData): User {
46    return new User(
47      data.id,
48      Email.reconstitute(data.email),
49      FullName.reconstitute(data.firstName, data.lastName),
50      data.role as UserRole,
51    );
52  }
53
54  // Méthode métier — émet un Domain Event
55  promoteToAdmin(): void {
56    if (this._role === 'admin') throw new DomainError('Déjà admin');
57    this._role = 'admin';
58    this._events.push(new UserPromotedToAdmin(this._id, new Date()));
59  }
60
61  get email(): string { return this._email.value; }
62  get fullName(): string { return this._name.full; }
63  get role(): UserRole { return this._role; }
64  get domainEvents(): DomainEvent[] { return [...this._events]; }
65  clearEvents(): void { this._events = []; }
66}