NestJs Event Store
NestJS CQRS module for EventStore.org. It requires @nestjs/cqrs.
## Installation
```bash
$ yarn install @hardyscc/nestjs-event-store
```
## Description
This module aims to bridge the gap between NestJs and [Event Store](https://eventstore.org). It supports all different subscription strategies of supported by Event Store.
Such as Volatile, CatchUp and Persistent subscriptions fairly easily.
### Setup from versions from `v2.0.0`
##### Setup root app module
```typescript
import { Module } from '@nestjs/common';
import { NestjsEventStoreModule } from '@hardyscc/nestjs-event-store';
@Module({
imports: [
NestjsEventStoreModule.forRoot({
tcpEndpoint: {
host: process.env.ES_TCP_HOSTNAME || AppConfig.eventstore?.hostname,
port: parseInt(process.env.ES_TCP_PORT, 10) || AppConfig.eventstore?.tcpPort,
},
options: {
defaultUserCredentials: {
password: AppConfig.eventstore?.tcpPassword,
username: AppConfig.eventstore?.tcpUsername,
},
},
}),
]
})
export class AppModule {}
```
## Setup module
_Note_ `featureStreamName` field is not important if you're subscription type is persistent'
```typescript
import { Module } from '@nestjs/common';
import { CommandBus, CqrsModule, EventBus } from '@nestjs/cqrs';
import {
NestjsEventStoreModule,
EventStore,
EventStoreSubscriptionType
} from '@hardyscc/nestjs-event-store';
import {
UserCommandHandlers,
UserCreatedEvent,
UserEventHandlers,
UserQueryHandlers
} from '../cqrs';
import { UserSagas } from './sagas';
@Module({
imports: [
CqrsModule,
NestjsEventStoreModule.forFeature({
featureStreamName: '$ce-user',
subscriptionsDelay: 2000, // Default is 0 (Optional)
subscriptions: [
{
type: EventStoreSubscriptionType.CatchUp,
stream: '$ce-user',
resolveLinkTos: true, // Default is true (Optional)
lastCheckpoint: 13 // Default is 0 (Optional)
},
{
type: EventStoreSubscriptionType.Volatile,
stream: '$ce-user'
},
{
type: EventStoreSubscriptionType.Persistent,
stream: '$ce-user',
persistentSubscriptionName: 'steamName',
resolveLinkTos: true // Default is true (Optional)
}
],
eventHandlers: {
UserLoggedInEvent: data => new UserLoggedInEvent(data),
UserRegisteredEvent: data => new UserRegisteredEvent(data),
EmailVerifiedEvent: data => new EmailVerifiedEvent(data)
}
})
],
providers: [
UserSagas,
...UserQueryHandlers,
...UserCommandHandlers,
...UserEventHandlers
]
})
export class UserModule {}
```
### Setup from versions below `v2.0.0`
#### Setup root app module
```typescript
import { Module } from '@nestjs/common';
import { NestjsEventStoreModule } from '@hardyscc/nestjs-event-store';
@Module({
imports: [
NestjsEventStoreModule.forRoot({
http: {
port: parseInt(process.env.ES_HTTP_PORT, 10),
protocol: process.env.ES_HTTP_PROTOCOL
},
tcp: {
credentials: {
password: process.env.ES_TCP_PASSWORD,
username: process.env.ES_TCP_USERNAME
},
hostname: process.env.ES_TCP_HOSTNAME,
port: parseInt(process.env.ES_TCP_PORT, 10),
protocol: process.env.ES_TCP_PROTOCOL
}
})
]
})
export class AppModule {}
```
#### Setup module
```typescript
import { Module } from '@nestjs/common';
import { CommandBus, CqrsModule, EventBus } from '@nestjs/cqrs';
import {
NestjsEventStoreModule,
EventStore
} from '@hardyscc/nestjs-event-store';
import {
UserCommandHandlers,
UserCreatedEvent,
UserEventHandlers,
UserQueryHandlers
} from '../cqrs';
import { UserSagas } from './sagas';
@Module({
imports: [
CqrsModule,
NestjsEventStoreModule.forFeature({
name: 'user',
resolveLinkTos: false
})
],
providers: [
UserSagas,
...UserQueryHandlers,
...UserCommandHandlers,
...UserEventHandlers
]
})
export class UserModule {
constructor(
private readonly command$: CommandBus,
private readonly event$: EventBus,
private readonly eventStore: EventStore
) {}
onModuleInit(): any {
this.eventStore.setEventHandlers(this.eventHandlers);
this.eventStore.bridgeEventsTo((this.event$ as any).subject$);
this.event$.publisher = this.eventStore;
}
eventHandlers = {
UserCreatedEvent: data => new UserCreatedEvent(data)
};
}
```
## Notice
`2.0.0` release inspired by [nestjs-eventstore](https://github.com/daypaio/nestjs-eventstore)
## License
This project is [MIT licensed](LICENSE).