@hexadrop/aggregate-root

Opinionated aggregate root base class for DDD

Installation

npm install --save @hexadrop/aggregate-root

Using bun

bun add @hexadrop/aggregate-root

What it does

• Default export is an abstract class AggregateRoot. This class provides the following:
  • A record(...events: DomainEvent[]) method to record events.
  • A pullDomainEvents(): DomainEvent[] method to get uncommitted events.
  • An abstract toPrimitives(): Primitives<this> method to convert the aggregate root to primitives.

How to use

import AggregateRoot from '@hexadrop/aggregate-root';
import DomainEvent from '@hexadrop/event';
import type { Primitives } from '@hexadrop/types/primitives';

class MockEvent extends DomainEvent {
  static override EVENT_NAME = 'event';

  constructor(
    readonly foo: string,
    aggregateId: string
  ) {
    super(MockEvent.EVENT_NAME, aggregateId);
  }
}

class MockAggregateRoot extends AggregateRoot {
  readonly foo: string;

  constructor(primitives: Primitives<MockAggregateRoot>) {
    super();
    this.foo = primitives.foo;
  }

  static create(foo: string): MockAggregateRoot {
    const aggregateRoot = new MockAggregateRoot({ foo });
    aggregateRoot.record(new MockEvent(foo, 'aggregateId'));

    return aggregateRoot;
  }

  override toPrimitives(): Primitives<MockAggregateRoot> {
    return {
      foo: this.foo,
    };
  }
}

Hexadrop Code Quality Standards

Publishing this package we are committing ourselves to the following code quality standards:

• Respect Semantic Versioning: No breaking changes in patch or minor versions
• No surprises in transitive dependencies: Use the bare minimum dependencies needed to meet the purpose
• One specific purpose to meet without having to carry a bunch of unnecessary other utilities
• Tests as documentation and usage examples
• Well documented README showing how to install and use
• License favoring Open Source and collaboration