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Daniel Boll for ExpressoTS

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A first project with ExpressoTS

Introduction

ExpressoTS is a new developer-friendly TypeScript framework for Server-Side Applications. It's currently built on top of Express, easy to get a new developer on board, light and easy project structure, two different project structure supported (opinionated and non opinionated version), supports MVC, non MVC, architecture. The opinionated template was built on top of clean architecture, you will see concepts embedded in the opinionated template such as entities, useCases, repositories and providers.

Setting Up Your First ExpressoTS Project

Ah, the first step to any great journey in the world of coding—a proper setup. Trust me, nobody wants to get lost before even starting the adventure. So, let's cut the chit-chat and dive right in.

Installation of ExpressoTS CLI

You've got two routes here, and the destination is the same, a functional ExpressoTS environment. Your first option is to install the ExpressoTS CLI globally:

pnpm i -g @expressots/cli
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Got limited commitment issues? No worries, you can also use dlx to run the CLI without installing it globally. Ah, the wonders of a one-night stand with a CLI!

pnpx @expressots/cli new expressots-first-project
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Configuration Wizard

After running the command, you're greeted by a friendly (albeit text-based) wizard 🧙‍♂️.

[🐎 Expressots]

? Project name expressots-first-project
? Package manager pnpm
? Select a template Non-Opinionated :: A simple ExpressoTS project.
? Do you want to create this project? Yes
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Fill out the form wisely but don't overthink it. For this tutorial, I'm going with the "Non-Opinionated" template because, it will give us a shallower learning curve in the start.

Getting Comfy in Your New ExpressoTS Home 🏡

Navigating to Your Project

So you've set up your new ExpressoTS project. Awesome! Time to get inside the engine room and take a look under the hood.

cd expressots-first-project
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You're now in the root folder, and if you're curious about what comes packed by default, run a quick tree command.

@expressots/tests/expressots-first-project via  v16.19.0
❯ tree -I node_modules -a
.
├── .eslintrc.js
├── expressots.config.ts
├── .gitignore
├── jest.config.ts
├── package.json
├── pnpm-lock.yaml
├── .prettierrc
├── README.md
├── src
│   ├── app.container.ts
│   ├── app.controller.ts
│   ├── app.module.ts
│   ├── app.usecase.ts
│   └── main.ts
├── test
│   └── app.usecase.spec.ts
├── tsconfig.build.json
└── tsconfig.json

3 directories, 16 files
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There you go! These are the files you'll be living with.

Customizing Your Prettier Preferences

You've got your own coding style—don't we all? You can tweak the .prettierrc file to your heart's content.

{
  "singleQuote": false,
  "trailingComma": "all",
  "endOfLine": "auto",
  "tabWidth": 2
}
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Let's Take a Quick Tour of package.json

A glance at the scripts section in package.json tells you all you need to know to get things up and running.

cat package.json | jq ".scripts"
{
  "prebuild": "rm -rf ./dist",
  "build": "tsc -p tsconfig.build.json",
  "dev": "tsnd ./src/main.ts",
  "prod": "node ./dist/main.js",
  "test": "jest",
  "test:watch": "jest --watchAll",
  "test:cov": "jest --coverage",
  "format": "prettier --write \"src/**/*.ts\" \"test/**/*.ts\"",
  "lint": "eslint \"src/**/*.ts\" --fix"
}
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Here, you've got your usual suspects: build, dev, test, and more.

Format All The Things!

Before diving into development, let's keep it neat. The format script will handle that.

pnpm format
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Running in Dev Mode

And finally, the moment you've been waiting for—fire up the dev server and see your app come to life!

@expressots/tests/expressots-first-project via  v16.19.0
❯ pnpm dev

[INFO] ts-node-dev ver. 2.0.0 (using ts-node ver. 10.9.1, typescript ver. 4.9.5)
Application version not provided is running on port 3000 - Environment: development
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Making Your First Request in ExpressoTS 🌐

Time for a Little Hello!

You've been through the house tour, you've feng shui'd your .prettierrc and got your scripts all figured out. Now what? Well, how about actually seeing your app in action?

Using HTTPie for Your First GET Request

For this demonstration, we're going to use HTTPie — the cURL for the 21st century. But like, way more readable. Here's how to send your first GET request to http://localhost:3000.

@expressots/tests/expressots-first-project via  v16.19.0
❯ http :3000
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Bam! You should see a response like:

HTTP/1.1 200 OK
...
Hello Expresso TS!
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Congrats! You just made your server say hello.

Anatomy of the "Hello Expresso TS!" 🦴

Alright, let's dissect that "Hello Expresso TS!" message. How does this simple string pass through layers of TypeScript files to make it to your browser? Spoiler: It's not magic; it's just well-structured code.

The Starting Point: src/main.ts

This is where the baton is picked up. Here, we import the essential parts from ExpressoTS and set up the initial application instance. Simple enough.

import "reflect-metadata";
import { AppInstance, ServerEnvironment } from "@expressots/core";
import { container } from "./app.container";

async function bootstrap() {
  AppInstance.create(container);
  AppInstance.listen(3000, ServerEnvironment.Development);
}

bootstrap();
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The Container: src/app.container.ts

Think of this as the backstage, where everyone gets ready for the show. It's where the application container is configured with your custom modules.

import { AppContainer } from "@expressots/core";
import { AppModule } from "./app.module";

const appContainer = new AppContainer();
const container = appContainer.create([AppModule]);

export { container };
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The Module: src/app.module.ts

Modules in ExpressoTS group related functionalities. Here, it's as simple as importing the AppController.

import { CreateModule } from "@expressots/core";
import { AppController } from "./app.controller";

const AppModule = CreateModule([AppController]);

export { AppModule };
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The Controller: src/app.controller.ts

This is the conductor of our orchestra. It's responsible for handling HTTP requests and directing traffic. In this case, it's just saying, "Hello Expresso TS!".

import { BaseController, controller, httpGet, response } from "inversify-express-utils";
import { Response } from "express";
import { AppUseCase } from "./app.usecase";

@controller("/")
class AppController extends BaseController {
  constructor(private appUseCase: AppUseCase) {
    super("app-controller");
  }

  @httpGet("/")
  execute(@response() res: Response) {
    return res.send(this.appUseCase.execute());
  }
}
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The Use Case: src/app.usecase.ts

Here's where the actual "Hello Expresso TS!" lives.

import { provide } from "inversify-binding-decorators";

@provide(AppUseCase)
class AppUseCase {
  execute() {
    return "Hello Expresso TS!";
  }
}
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"Hello, Who?" Changing the Default Response 🖊️

Got bored of the usual "Hello Expresso TS!"? Let's give it a personal touch. To do that, we only need to venture into the src/app.usecase.ts file. See, this is the beauty of a well-structured codebase; you don't have to jump through hoops to make a simple change.

The Tweak: src/app.usecase.ts

One line change. That's it. Here we just swap out the text to "Hello from <Daniel::Boll>".

@provide(AppUseCase)
class AppUseCase {
  execute() {
    return "Hello from <Daniel::Boll>";
  }
}
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The Reload: Auto-refresh FTW

As soon as you save that change, the development server detects this update and reloads itself. No manual effort required. Ah, the joys of modern development.

[INFO] Restarting: /../@expressots/tests/expressots-first-project/src/app.usecase.ts has been modified
Application version not provided is running on port 3000 - Environment: development
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The Result: Let's Talk to the Server Again

Run the command, and voila! The updated greeting is now served hot, right from your server.

Hello from <Daniel::Boll>
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Dive deeper

If you are interested in more stuff you can do in this simple ExpressoTS project make sure to check out the full blog at daniel-boll.me.

Top comments (35)

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akash_dathan profile image
Akash Dathan

Looks similar to NestJS

Have you tried NestJS? If yes, can you highlight some differences or advantages?

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rsaz profile image
Richard Zampieri

But way different, specially in philosophy. Here are few items I would describe:

  • Providers offered in the tool as part of the application life cycle without the need of installation first to use.
  • Easy to get a new developer on board.
  • Light and easy project structure
  • Two different project structure supported (opinionated and non opinionated version), supports MVC, non MVC, architecture. The opinionated template was built on top of clean architecture, you will see concepts embedded in the opinionated template such as entities, useCases, repositories and providers. In the other hand Nest is purely MVC heavily inspired by Angular

Mostly, you feel like what you are building is tangible rather than feeling like you’re building a server-side app on top of a lots of stuff underneath that you don’t know exactly what is going on. In Expresso everything is exposed, like DI, Middleware stack and so on. ExpressoTS is not inspired by a Framework but inspired by good practices in many different well established framework such as .NET, Spring boot etc.

These are the few ones that came up to my mind now. I hope it helps, give a try, and draw your conclusions.

By the way, folks are about to release v2.0 soon with a lots of changes and more interesting features that you don't see often in Typescript ecosystem

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akash_dathan profile image
Akash Dathan

Nice, thanks for the update though, ill definitely try it out.

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malpaso profile image
Bill Tindal

Try @adonisframework instead

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danielhe4rt profile image
Daniel Reis

I was one of the beta testers of this awesome framework. I hope that ExpressoTS gets the space neeeded to keep growing in the OSS community.

Also, thanks for the article folks!

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gbrramos profile image
Gabriel Oliveira

Awesome! I'm sure I'll use this framework so much

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edintwi profile image
Edson Brandon

good!

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wesllycode profile image
wesllycode

Very nice !

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patriciooncode profile image
Patricio

Thank you for this.

I tried to add TS in a production project, and eventually gave up because it was more blocking than helping.

So with ExpressoTS, things will become more simple, thank you!

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rsaz profile image
Richard Zampieri

Great article, keep it up the good work!

Version 2.0 is coming soon!

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cherryramatis profile image
Cherry Ramatis

Awesome article! It's awesome to see more iniciative around backend typescript development, quite curious to try out on my own projects

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viniciusenari profile image
Vinicius Koji Enari

Awesome! I'm looking forward to try ExpressoTS!

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llofyy profile image
Lucas André

This is very cool!

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julianosoares profile image
Juliano Leonardo Soares

Excellent article!

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mattheushenrique profile image
Ma77heus

Good article!! Vai Brasil! ❤️

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imglic profile image
Victor Glicério

Nice job bro!

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nandosts profile image
Fernando Melo

This is actually awesome!

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krtirtho profile image
Kingkor Roy Tirtho

Wait a sec. Isn't it just another NestJS clone?
The same modules, controllers, providers, usecases (fancy word for Nestjs Middlewares) & of course decorators

I love the what NestJS does. But what is the point of straight up copying a framework? This doesn't bring any uniqueness to this project at all

Even the logo of the project is another ripoff of NestJS's logo. A horse instead of a cat/tiger

Ah this is just disappointing 😔

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indexofmayank profile image
Mayank Tiwari

True