Bootstrapping.md

Fastify decorators

Bootstrapping is the process of starting up, in this stage library initialize all controllers, services and their dependencies. This Initialization is done before Fastify instance starts listen.

Autoload all controllers

One of the options to bootstrap app is autoload feature, it uses path and mask to load controllers and/or handlers.

Example:

import { fastify } from 'fastify';
import { bootstrap } from 'fastify-decorators';

const app = fastify();

app.register(bootstrap, {
  directory: import.meta.url,
  mask: /\.controller\./,
});

Specifying controllers list

Second option available is to specify all required controllers and/or handlers via array. This way you will have more granular control on whatever to load.

Example:

import { fastify } from 'fastify';
import { bootstrap } from 'fastify-decorators';

// With default export
import MyController from './my-controller.js';

// With named export
import { SecondController } from './second-controller.js';

const app = fastify();

app.register(bootstrap, {
  controllers: [MyController, SecondController],
});

Using custom class loader

By default, fastify-decorators uses own DI mechanism for getting controller instances. This mechanism depends on reflect-metadata and provide basic abilities like constructor injection and injection to class fields via decorators.

You can read more about built-in DI at Services and dependency injection

In case when built-in DI does not suitable it's possible to write own custom loader for classes and pass it via classLoader option. Signature is (clazz: Constructor<C>) => C.

import 'reflect-metadata';
import { Container } from 'typedi';

app.register(bootstrap, {
  // ...other options...
  classLoader(clazz) {
    return Container.get(clazz);
  },
});