TypeScript Sample Web Service

What's this about?

This repository contains an opinionated example of a simple Node/TypeScript web service. It's aimed to give non-Node/TS developers an idea of what a simple web application can look like and might serve as a starter for other projects.

Note that there is also an advanced branch of this project that aims to be an example of an Onion Architecture approach and uses some of TypeScript's more advanced utility types to solve common dependency problems.

This application needs a running mongodb instance to work. If no DB_CONN_URL environment variable containing a mongodb connection url is passed, the application falls back to mongodb://127.0.0.1:27017. If you don't have a running mongodb instance at hand, you can start one running docker run --name some-mongo -p 127.0.0.1:27017:27017 -d mongo, assuming you have docker installed.

Before usage, run npm install.

You can use this service by running:

• npm run build to build the application
• npm run start to (build and) start the application
• npm run serve to start the application in watch mode
• npm run test to run the sample tests

Some opinionated stuff

This application uses some extra packages that can be handy for slightly larger services:

• expressjs might be the most popular Node.js web framework out there
• The routing controllers packages allows to simply declare controllers via decorators, much like in Java Spring with annotations.
• The typedi package allows to declare and inject services for DI/IOC.
• I do use mongodb (just because it's easy for an example). I do not use an ORM like mongoose, mainly because ORMs are magic, performance eating monsters that aren't needed if you work with a document database (opinionated).

Please be aware that these are just examples. There are other good packages out there for all of these purposes.

Services are currently named via a string constant (as seen in the @Service(...) decorators). This is not a must. It helps to identify services and to exchange an injected services for testing purposes.

Some pitfalls

• New services (with the @Service() class decorator) have to be registered in the app.ts class constructor.
• New controllers also have to be registered in the app.ts constructors.

Disclaimer

This is obviously just a sample project. There are some things that are missing or incomplete. For example:

• The DbFactory class does not have a reconnect mechanism in case the first database connection fails.
• There are currently no validations for incoming http payloads in place. Please add some before you put anything in production (joi is a popular choice for more complex validations).
• I included some tests, mainly to show how tests can be done easily. You should probably have better test coverage.
• Please update these projects dependencies before you use it.

If you there is anything you don't understand, bugs or requests, please don't hesitate to write me a mail.