AggregateRepository

Defined in: packages/ddd-mikro-orm/src/repository/aggregate.repository.ts:58

Base class for the command repositories that load and save an existing aggregate.

Provides authoritative aggregate hydration via findById:

• Bypasses read-side caches (@FromCache) to prevent stale reads on mutation paths.
• Forces MikroORM { refresh: true } to avoid returning stale Unit-of-Work identity-map entities.
• Translates low-level driver failures through mapPersistenceError into application-neutral transient signals.

Concrete repositories extend this class, inject dependencies into super(...), and provide their decorated save() method, usually through @PersistedWrite. The store is any IEntityManagerSource, typically the application’s own store; its em is also what save() passes to optimisticUpdate or optimisticDelete.

Example

// A NestJS provider; STORE is the application's IEntityManagerSource token.
@Injectable()
export class UpdateUserCommandRepository extends AggregateRepository<
  UserSnapshot,
  User,
  UserSnapshot
> {
  constructor(
    @Inject(CACHE_TOKEN) cache: ICache<UserSnapshot>,
    @Inject(STORE) store: IEntityManagerSource,
  ) {
    super(cache, store, User, User.aggregateName, User.fromJSON);
  }

  @PersistedWrite<User>({
    unique: { email: (user) => new UniqueEmailException(user) },
  })
  async save(user: User): Promise<UserSnapshot> {
    ...
  }
}

Extends

• CommandRepository<TEntity, TResult, TSnapshot>

Type Parameters

TSnapshot

TSnapshot extends Partial<RootEntitySnapshot>

Snapshot structure of the aggregate.

TEntity

TEntity extends RootEntity<TSnapshot>

Domain aggregate class extending RootEntity.

TResult

TResult = unknown

Persisted result type returned by save().

Implements

• IWriteSideAggregateRepository<TEntity>

Constructors

Constructor

new AggregateRepository<TSnapshot, TEntity, TResult>(cache, store, entityClass, aggregateName, hydrateFn): AggregateRepository<TSnapshot, TEntity, TResult>

Defined in: packages/ddd-mikro-orm/src/repository/aggregate.repository.ts:66

Parameters

cache

ICache<TSnapshot>

store

IEntityManagerSource

entityClass

EntityName<TEntity>

aggregateName

string

hydrateFn

(snapshot) => TEntity

Returns

AggregateRepository<TSnapshot, TEntity, TResult>

Overrides

CommandRepository.constructor

Properties

aggregateName

protected readonly aggregateName: string

Defined in: packages/ddd-mikro-orm/src/repository/aggregate.repository.ts:70

---

cache

protected readonly cache: ICache<TSnapshot>

Defined in: packages/ddd-core/dist/persistence/command-repository.abstract.d.ts:35

Inherited from

CommandRepository.cache

---

entityClass

protected readonly entityClass: EntityName<TEntity>

Defined in: packages/ddd-mikro-orm/src/repository/aggregate.repository.ts:69

---

hydrateFn

protected readonly hydrateFn: (snapshot) => TEntity

Defined in: packages/ddd-mikro-orm/src/repository/aggregate.repository.ts:71

Parameters

snapshot

TSnapshot

Returns

TEntity

---

store

protected readonly store: IEntityManagerSource

Defined in: packages/ddd-mikro-orm/src/repository/aggregate.repository.ts:68

Methods

findById()

findById(id): Promise<TEntity | null>

Defined in: packages/ddd-mikro-orm/src/repository/aggregate.repository.ts:99

Loads the authoritative aggregate directly from persistence.

Enforces { refresh: true } so that if the entity was already loaded in the active EntityManager’s identity map, its columns are re-fetched from the database before domain mutations and optimistic concurrency checks take place. The manager comes from store.em, read for this call.

Parameters

id

string

The aggregate identifier.

Returns

Promise<TEntity | null>

Rehydrated aggregate instance, or null if not found.

Throws

If a retryable database connection or driver error occurs.

Implementation of

IWriteSideAggregateRepository.findById

---

save()

abstract save(entity): Promise<TResult | null>

Defined in: packages/ddd-core/dist/persistence/command-repository.abstract.d.ts:37

Persists the aggregate/payload.

Returning null is the conventional deletion result used by the DDD cache decorator to trigger eviction/barrier behavior.

Parameters

entity

TEntity

Returns

Promise<TResult | null>

Implementation of

IWriteSideAggregateRepository.save

Inherited from

CommandRepository.save