fastify-decorators

Fastify decorators

This package developed to provide useful typescript decorators to implement RequestHandler pattern with Fastify.

NOTE: Fastify-decorators was developed with fastify ^2.0.0 and may not work with other versions.

Install

via npm:

npm install fastify-decorators --save

via yarn:

yarn add fastify-decorators

Basic usage

index.ts:

import { bootstrap } from 'fastify-decorators';
import fastify = require('fastify');
import { join } from 'path';

// Create Fastify instance
const instance = fastify();

// Register handlers auto-bootstrap
instance.register(bootstrap, {
    handlersDirectory: join(__dirname, `handlers`),
    handlersMask: /\.handler\./
});

instance.listen(3000);

handlers/sample.handler.ts:

import { GET, RequestHandler } from 'fastify-decorators';

@GET({
    url: '/sample'
})
class SampleHandler extends RequestHandler {
    async handle() {
        return 'It works!';
    }
}

// We should export class to make it accessible to bootstraper
export = SampleHandler;

NOTE: Using decorators require experimentalDecorators to be enabled in tsconfig.json

otherwise decorators won't work but you still can use it without them:

import { GET, RequestHandler } from 'fastify-decorators';

class SampleHandler extends RequestHandler {
    async handle() {
        return 'It works!';
    }
}

// BTW decorators is just a functions :)
export = GET({ url: '/sample' })(SampleHandler);

API

bootstrap

bootstrap is Fastify plugin to autoload all decorated modules

example:

import fastify = require('fastify');
import {bootstrap} from 'fastify-decorators';

const instance = fastify();

instance.register(bootstrap, options)

Bootstrap options

name	type	required	description
handlersDirectory	string	yes	Specify directory where handlers are located
handlersMask	string, RegExp	no	Specify mask for files filter
prefix	string	no	Specify prefix for routes

Decorators

List of available decorators:

• GET
• POST
• PUT
• DELETE
• HEAD
• OPTIONS
• ALL

example:

import { POST, RequestHandler } from 'fastify-decorators';

@POST(options)
class SimpleHandler extends RequestHandler {
    async handle() {return ''}
}

export = SimpleHandler;

Decorators options

name	type	required	description
url	string	yes	Route url which will be passed to Fastify
options	RouteConfig	no	Config for route which will be passed to Fastify

How it works

Under the hood decorators create static method register in your class and then bootstraper use it to register it.

It means that this code:

import { PUT, RequestHandler } from 'fastify-decorators';

@PUT({
    url: '/sample'
})
class SimplePutHandler extends RequestHandler {
    async handle() {
        return this.request.body.message;
    }
}

export = SimplePutHandler;

becomes:

import { FastifyInstance, FastifyReply, FastifyRequest } from 'fastify';
import { REGISTER } from 'fastify-decorators';
import { IncomingMessage, ServerResponse } from 'http';

class SimplePutHandler {
    constructor(protected request: FastifyRequest<IncomingMessage>,
                protected reply: FastifyReply<ServerResponse>) {
    }

    async handle() {
        return this.request.body.message;
    }

    static [REGISTER] = (instance: FastifyInstance) => instance.put(`/sample`, {}, (req, res) => new SimplePutHandler(req, res).handle());
}

export = SimplePutHandler;

License

This project licensed under MIT License