snatalenko / node-cqrs / 10223191268

import { IEvent, IEventStorage, IEventSet, IEventStream } from "../interfaces";

import { nextCycle } from "./utils";

/**

 * A simple event storage implementation intended to use for tests only.

 * Storage content resets on each app restart.

 *

 * @class InMemoryEventStorage

 * @implements {IEventStorage}

 */

export class InMemoryEventStorage implements IEventStorage {

        #nextId: number = 0;

        #events: IEventSet = [];

        async commitEvents(events: IEventSet): Promise<IEventSet> {

                await nextCycle();

                this.#events = this.#events.concat(events);

                await nextCycle();

                return events;

        }

        async getAggregateEvents(aggregateId, options?: { snapshot: IEvent }): Promise<IEventSet> {

                await nextCycle();

                const afterVersion = options?.snapshot?.aggregateVersion;

                const result = !afterVersion ?

                        this.#events.filter(e => e.aggregateId == aggregateId) :

                        this.#events.filter(e =>

                                e.aggregateVersion > afterVersion);

                await nextCycle();

                return result;

        }

        async getSagaEvents(sagaId, { beforeEvent }): Promise<IEventSet> {

                await nextCycle();

                const results = this.#events.filter(e =>

                        e.sagaId == sagaId &&

                        e.sagaVersion !== undefined &&

                        e.sagaVersion < beforeEvent.sagaVersion);

                await nextCycle();

                return results;

        }

        async* getEvents(eventTypes): IEventStream {

                await nextCycle();

                for await (const event of this.#events) {

                        if (!eventTypes || eventTypes.includes(event.type))

                                yield event;

                }

        }

        getNewId(): number {

                this.#nextId += 1;

                return this.#nextId;

        }

}