@node-idempotency/nestjs
Nestjs wrapper for Node-Idempotency.
Implements @node-idempotency/core
as a nestjs interceptor.
Why?
Internet requests are unpredictable; clients/proxies may send duplicate or concurrent requests due to retries or network issues. To ensure smooth operation, servers must process each request only once. This package detects and handles duplicates, preventing issues like double charging the customer. It's:
- Race Condition free: Ensures consistent behavior even during concurrent requests.
- Modular: Easily integrates with your storage or existing implementation, adding a decorator makes the endpoint idempotent.
- Customizable: options to tweak the library as per your need.
- RFC compliant: Adheres to standards for compatibility with other systems/clients.
instal
npm i @node-idempotency/nestjs
usage
- Register the module
import { NodeIdempotencyModule } from '@node-idempotency/nestjs';
@Module({
imports: [
NodeIdempotencyModule.forRootAsync({
storage: {
adapter: StorageAdapterEnum.memory,
options: ,
},
...idempotencyOptions,
}),
],
})
export class AppModule {}
storage.adapter
can either be memory
, redis
or an instance of Storage
interface.storage.options
are options to the storage client, required for redis
, is client options of redis client.idempotencyOptions
are the IdempotencyOptions
passed to @node-idempotency/core/Idempotency
- Decorate controllers or handlers
import { Controller, Get, Post, HttpCode, Body } from "@nestjs/common";
import { Idempotent } from "@node-idempotency/nestjs";
@Controller()
@Idempotent({ ...idempotencyOptions })
export class CounterController {
counter = 0;
@Get()
getNumber(): number {
return this.counter++;
}
@Post()
@HttpCode(201)
async addNumber(@Body() { number }: { number: number }): Promise<number> {
this.counter += number;
return this.counter;
}
}
- Decorating selected handlers
import { Controller, Get, Post, HttpCode, Body } from "@nestjs/common";
import { Idempotent } from "@node-idempotency/nestjs";
@Controller()
export class CounterController {
counter = 0;
@Idempotent({ ...idempotencyOptions })
@Get()
getNumber(): number {
return this.counter++;
}
@Post()
@HttpCode(201)
async addNumber(@Body() { number }: { number: number }): Promise<number> {
this.counter += number;
return this.counter;
}
}
Library also exports the interceptor, you can use it like you would use any nestjs interceptors(ex: registering globaly)
import { NodeIdempotencyInterceptor } from "@node-idempotency/nestjs";