npm package: @hardyscc/nestjs-event-store
Description: NestJS CQRS module for EventStore.org CQRS
Author: Rex Isaac Raphael
Latest version: 2.0.7

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NestJs Event Store
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  NestJS CQRS module for EventStore.org. It requires @nestjs/cqrs.
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</p>

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## 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).