nestore-js-mongodb

Event store for Node.js and with MongoDb as storage. An event store is where events are stored when using the Event Sourcing pattern.

This project was born as a porting in Node.js of NEstore, an event store for .NET Framework.

Written and compatible with Typescript.

Installation

npm install nestore-js-mongodb

Usage

Connecting and disconnecting:

const eventStore = new EventStore({url: "mongodb://localhost"});
await eventStore.connect();
const bucket = eventStore.bucket("wcm");
// TODO call function on bucket to read and write on the event store, see below
await	eventStore.close();

Connect to the store only at the start of your application and disconnect at the end.

How to read and write events

import * as nestore from "../index";

const eventStore = new nestore.EventStore({url: "mongodb://localhost:27017/myDb"});

async function writeAndRead() {
  const bucket = eventStore.bucket("sample1");

  const streamId = bucket.randomStreamId(); // shortcut to uuid.v4()
  const options: nestore.WriteOptions = { dispatched: true };

  await bucket.write(streamId, 0, [{name: "A"}], options);
  await bucket.write(streamId, 1, [{name: "B"}], options);

  const commits = await bucket.getCommitsArray({ streamId });

  console.log(commits[0].Events[0].name); // print A
  console.log(commits[1].Events[0].name); // print B
}

async function doWork() {
  await eventStore.connect();
  try {
    await writeAndRead();
  }	finally {
    await	eventStore.close();
  }
}

doWork();

See ./samples for more usage examples.

bucket.write

Write new events

bucket.write(
  streamId: string,
  expectedStreamRevision: number,
  events: any[],
  options: WriteOptions = { dispatched: false }): Promise<WriteResult>

bucket.getCommitById

Get a commit by id.

bucket.getCommitById(id: number): Promise<CommitData | undefined>

bucket.getCommitsArray

bucket.getCommitsArray(filters?: CommitsFilters, options?: CommitsOptions): Promise<CommitData[]>

bucket.lastCommit

bucket.lastCommit(filters?: CommitsFilters, options?: CommitsOptions): Promise<CommitData | undefined>

bucket.updateCommit

bucket.updateCommit(id: number, events: any[]): Promise<CommitData | undefined>

bucket.streamRevision

bucket.streamRevision(streamId: string): Promise<number>

1.x -> 2.x BREAKING CHANGES

From nestore-js-mongodb 2.x the feature that allows to keep open the event stream is DEPRECATED