@gedai/nestjs-core

Description

Seamless asynchronous local storage management using the NodeJS Async Local Storage. This package is designed as a core component for the gedai project, and offers plug-and-play functionality, empowering developers to effortlessly integrate asynchronous local storage into their applications.

Getting Started

Step 1: Installation

Install the necessary packages with your favorite Package Manager.

$ npm install @gedai/core

Step 2: Configuration Setup

In your app.module.ts import ContextModule and set it up.

// app.module.ts
import { ContextModule } from '@gedai/core';
import { Module } from '@nestjs/common';
import { randomUUID } from 'crypto';
import { AppController } from './app.controller';
import { AppService } from './app.service';

@Module({
  imports: [
    // Setup Context Module Here
    ContextModule.forRoot({}),
  ],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

In main.ts import the apply the required configuration with configureContextWrapper.

// main.ts
import { configureContextWrappers } from '@gedai/core';
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create(AppModule)
    // Setup Context Wrappers Here
    .then(configureContextWrappers);

  await app.listen(3000);
}
bootstrap();

Step 3: Usage

In your services, add ContextService as an injectable dependency.

// app.service.ts
import { ContextService } from '@gedai/core';
import { Injectable } from '@nestjs/common';

@Injectable()
export class AppService {
  // Injected here
  constructor(private readonly context: ContextService) {}

  getHello(): string {
    // Recover any previously set property
    const contextId = this.context.getId();
    return `[${contextId}]: Hello World!`;
  }
}

Important Consideration Regarding AsyncLocalStorage and Continuation Passing Style

Implementing continuation passing style introduces complexity to systems. While it's a viable method for data sharing across layers and components, exercising caution is paramount. It's remarkably easy to lose oversight of stored data within the context, potentially leading to bugs or leaks.

Potential Use Cases:

• Tracking Execution Context: Utilize to share a traceId throughout the request lifecycle, facilitating seamless monitoring and debugging.
• Automatically Managing Database Transactions: Implement for streamlined transaction handling, ensuring data integrity and consistency. Ability to handle the transactions without touching the business layers.
• Tracking Tenant Shard ID: Employ for efficient tracking and management of tenant-specific data shards, enhancing multi-tenancy support and scalability without having to pass properties everywhere in your code.

License

Gedai is MIT licensed.