Clean Express Node TypeScript Server

Table of Contents

1. Getting Started
   • NPM Scripts
   • Linting
2. Architecture
   • Core
   • Controllers and Models
3. Progress
   • Todos

Getting Started

To start a repo from this template, press the Use this template button at the top of the page. After cloning the repo started from this template, create a .env file matching the shape of .env.example. Any additions to your .env should be added to src/config/index.ts as methods on the env object so that they produce meaningful errors if future collaborators haven't configured their environment properly. Either rename or delete this README.md and rename APP_README.md to README.md.

NPM Scripts

# Run app in development
npm run dev

# Build `.js` files
npm run build

# Run app off of build
npm start

Linting

The CENTS template uses eslint for linting. The eslint extension in VS Code should give you syntax highligthing for errors and warnings. If you use a different IDE or editor you can run ./node_modules/.bin/eslint in the terminal at the working directory of the server app. The configuration extends Airbnb's style guide with certain rules disabled. Linting is meant to maintain consistent code style across collaboration, and reduce focus on granular syntax in code review. The eslintrc.json is a work in progress, if there are additional rules you think it needs please create a GitHub issue or submit a pull request.

Architecture

The CENTS template follows Robert Martin's diagram of clean architecture. A diagram of CENTS' implemenation of this architecture lives in this repo wiki.

Core

The main patterns used from clean architecture is inversion of dependency and dependency injection. The business logic of the application is isolated from the application's dependencies, and lives inside of the /core directory. Data types of our "business objects" are defined in the /core/Entities directory. The flow of data is defined in the /core/UseCases directory. The interfaces and implementations of our persistence strategy and its dependency injection is defined in /core/Adapters. The FsAdapter.ts module is an example implementation simply using Node's file system module to read and write from a .txt file to persist our data in /db/db.txt. Further details are provided in in-line code documentation.

Controllers and Models

Our models are implementations of our PersistenceAdapter interface that are instantiated with its dependencies. In the case of FsAdapter, it is instantiated with the fs library and the path to the db.txt file.

Our controllers are implementations of our UseCases instantiated with our model, and any other dependencies. For example /controllers/usersControllers.ts takes a model and a uuid module to create an id for Entity object in our collection.

HTTP Dependencies

Core contains the business rules. In order to apply them to an HTTP server we're using Express as our routing and middleware framework. Core doesn't have knowledge of Express, so in order to use our controller in our Express routes, we wrap the controller in a RequestAdapter that fits the shape of the callback expected by Express and passes the correct arguments to our controller.

Progress

This repo is a work in progress. Feel free to submit issues and pull requests. The efficacy of the template will improve with usage and hitting edge cases.

Todos

These todos encapsulate next actions for this template. They will capture in this repo's issues.

• Add testing
• Incorporate Auth0
• Implement Postgres adapter
• Implement Mongoose adapter
• Include CI/CD boilerplate