FileEventStore replaces previous events when appending new ones

[sylvaindesve]

triviality/packages/eventsourcing/src/EventStore/FileEventStore.ts

Lines 67 to 72 in 6f69168

	public async append(id: Identity, eventStream: DomainEventStream): Promise<void> {
	const events = await eventStream.pipe(toArray()).toPromise();
	const serialized = events.map((event) => toFile(event, this.serializer));
	this.fileSystem.writeFileSync(this.file, JSON.stringify(serialized));
	await this.repository.append(id, eventStream);
	}

This code writes the newly appended events to file, replacing older events.
This should load previous events from the InMemoryRepositoryStore and concat the new ones before saving to file.