nestjs-fetch-module

nestjs-fetch-module

A lightweight NestJS wrapper around the native fetch() API.

The Fetch API is awesome, but until recently we have needed a library to use it with Node. As of Node 18, Fetch is available by default (based on the undici library). This library wraps a small API around native fetch() so it can be used in NestJS instead of @nestjs/axios.

Note: This is not a drop-in replacement for @nestjs/axios or the HttpModule. It has a completely different API.

Installation

npm install nestjs-fetch-module

Usage

Import the FetchModule in your application module.

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { FetchModule } from 'nestjs-fetch-module';

@Module({
	imports: [FetchModule],
	controllers: [AppController],
	providers: [AppService],
})
export class AppModule {}

The FetchService is now available as a provider in your application.

import { Injectable } from '@nestjs/common';
import { FetchService } from 'nestjs-fetch-module';

@Injectable()
export class AppService {
	constructor(private readonly fetch: FetchService) {}

	async getExample(): Promise<string> {
		const response = await this.fetch.get('http://example.com/');
		return response.text();
	}
}

API

The public API presents six helper methods for making HTTP requests. The first argument to each method is a URL (either a URL object or a string); the second argument is an optional list of configuration options.

Each of these helpers returns a Response object. This Response object is documented over on MDN. You will probably want to await response.json() or response.text() to retrieve the body content.

interface FetchService {
	get(url: URL | string, options?: FetchModuleOptions): Promise<Response>;
	head(url: URL | string, options?: FetchModuleOptions): Promise<Response>;
	post(url: URL | string, options?: FetchModuleOptions): Promise<Response>;
	put(url: URL | string, options?: FetchModuleOptions): Promise<Response>;
	patch(url: URL | string, options?: FetchModuleOptions): Promise<Response>;
	delete(url: URL | string, options?: FetchModuleOptions): Promise<Response>;
}

FetchModuleOptions includes all the options you can send to a Request object, plus one additional option: baseUrl. If you supply a relative URL as the argument to the FetchService then it will be resolved against the baseUrl.

Configuration with Nest

Set up as a provider in your app module:

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { FetchModule } from 'nestjs-fetch-module';

@Module({
	imports: [FetchModule.register({ baseUrl: 'http://example.com' })],
	controllers: [AppController],
	providers: [AppService],
})
export class AppModule {}

Async set up is also supported.

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { FetchModule } from 'nestjs-fetch-module';
import { ConfigModule, ConfigService } from '@nestjs/config';

@Module({
	imports: [
		ConfigModule.forRoot({ isGlobal: true }),
		FetchModule.registerAsync({
			inject: [ConfigService],
			useFactory(config: ConfigService) {
				return { keepalive: config.get('ENABLE_KEEPALIVE') };
			},
		}),
	],
	controllers: [AppController],
	providers: [AppService],
})
export class AppModule {}

Requirements

• A version of Node with native fetch(); >=17.5 with fetch() flagged on, or >=18.0 which has fetch() enabled by default.
• NestJS >= 8.x

License

This project is MIT licensed.