@enhanced-nestjs/request-context

Overview

@enhanced-nestjs/request-context is a lightweight context service for NestJS applications leveraging the async_hooks feature in Node.js. It provides a structured way to handle and propagate request-specific data across different parts of your application, without having to rely on manual context passing.

Features

• Based on Node.js's async_hooks API for efficient context handling.
• Simple API to set, get, check, and delete the request context.
• Provides isolation of request data in asynchronous environments.
• Designed specifically for NestJS but can be adapted for other frameworks.

Installation

To use this library, you'll need Node.js and Yarn set up in your project. Install the package using Yarn:

yarn add @enhanced-nestjs/request-context

Or using npm:

npm install @enhanced-nestjs/request-context

Peer Dependencies

Make sure you have the following peer dependencies installed in your project:

• TypeScript >4.0.0

Usage

Here's a basic example of how to use the RequestContextService in a NestJS application.

Basic Example

import { Injectable, NestMiddleware } from '@nestjs/common';
import { RequestContextService } from '@enhanced-nestjs/request-context';

@Injectable()
export class ContextMiddleware implements NestMiddleware {
  constructor(private readonly requestContextService: RequestContextService<{userId: string, token: string}>) {}

  use(req: Request, res: Response, next: Function) {
    this.requestContextService.set({ userId: req.headers['x-user-id'], token: req.headers['Authorization'] });
    next();
  }
}

Accessing the Context

You can access the context from anywhere in your application's flow, as long as you are in the same async boundary.

import { Injectable } from '@nestjs/common';
import { RequestContextService } from '@enhanced-nestjs/request-context';

@Injectable()
export class SomeService {
  constructor(private readonly requestContextService: RequestContextService<{userId: string, token: string}>) {}

  someFunction() {
    const context = this.requestContextService.get();
    if (context) {
      console.log(`Current User ID: ${context.userId}`);
    }
  }
}

API

• set(value: T): void: Sets the context value for the current async operation.
• get(): T | undefined: Retrieves the current context value.
• has(): boolean: Checks if the context is currently set.
• delete(): void: Deletes the current context.

License

This project is licensed under the MIT License - see the LICENSE file for details.