ts-async-bootstrap

Easily setup async typescript applications!

Rationale

When writing node applications, it's a good idea to split up your initialization (database setup, logging setup, etc) from your application entrypoint, that way the initialization can be used for other entry-points (such as admin scripts, scheduled tasks, etc). This package assists bootstrapping the initialization and main function, as well as error handling.

Setup

Install

npm i ts-async-bootstrap

Usage (Option 1)

import { bootstrap } from '../src';

async function setup(): Promise<void> {
	// TODO: Setup some stuff!
}

async function main(): Promise<void> {
	// TODO: Run some stuff!
}

async function errorHandler(e): Promise<void> {
	// TODO: Log some stuff!
}

/**
 * Bootstrap the application
 */
bootstrap({
	register: setup,
	run: main,
	errorHandler: errorHandler
});

Usage (Option 2)

import { Bootstrap } from 'ts-async-bootstrap';

class AppBootstrap extends Bootstrap {
	register = () => {
		// TODO: Setup some stuff!
	}

	onError = (e: Error) => {
		// TODO: Log some stuff!
	}
}

async function main(): Promise<void> {
	// TODO: Run some stuff!
}

export const app = new AppBootstrap();
app.boot(main);

Lifecycle

Register

First, bootstrap() calls your register function, which will setup any dependencies/services/etc before running the main function

Run

Next, your run function is called. This could be the main function of the application, or a admin/scheduled task

Exit

After the run function completes, the onComplete method will be called.

Error

If an exception is thrown or a promise is rejected during register or run, the errorHandler function will be called.

• If shouldExitOnError is true (default), the application will exit with a non-zero exit code
• If errorHandler is not set, console.error will be used to log the error
• If the error occured in the register function, the run function will not be called

Finally

Regardless of success or fail, onFinally will run after onComplete or errorHandler.