This is sample TSOA starting project demonstrating its basic features. TSOA requires its consumer to implement IoC interface. This, however, doesn't imply your entire application needs to be IoC driven! This project also show option how to localize usage of IoC to minimum.

The project defines single API controller ResourceController.ts taking advantage of amazing TSOA capabilities. TSOA generates code which wraps around our ResourceController.ts and is also responsible for instantiation of the controller. But Controllers can often have complex constructors, depending on various internal services objects of our applications.

We need to provide TSOA with simple way of instantiating these controllers. That's why TSOA relies on IoC container to hide away "how" the instantiation happens, and instead provide simple interface, such as: "give me instance of type ResourceController".

Install dependencies

yarn

Run in development mode - This will automatically rebuild tsoa generated code, and restart application server anytime our source code OR tsoa-generated code is updated.

yarn dev

Test

curl -v -XGET http:https://localhost:3000/resources/  -H 'Content-Type: application/json'

which should return 200 OK response, and the server will log:

[0] Built FooService a2c43ee146e214d0ae3d3c4751573a56
[0] Foo instance a2c43ee146e214d0ae3d3c4751573a56 getting the Foo
[0] Bar instance 42bc3cb5ec579e5d3172812aade18456 getting the Bar
[0] Baz instance 9bc0978a3fb1232d577a41546ba562f2 getting the Baz

It can seem that adopting TSOA for existing project is invasive, because now you need to introduce IoC framework to build your controllers!

Yes, TSOA largerly drive how your Controller layer looks like:

• You need to provide IoC container which can build instance for any API Controller class
• Your controller classes need to extend class Controller from tsoa
• You use tsoa annotations - which are powerful and are the reason why you are considering to adopt tsoa in a first place.

But TSOA doesn't need to impact rest of your application. Everything else can stay as is, you just need to register dependencies of all Controllers in the IoC container. In the project code, the ResourceController.ts controller has 3 dependencies: FooService, BarService, BazService.

The FooService, BarService are doubling down on the IoC framework, using annotations of tsyringe. However BazService is untouched and itself is unaware of IoC or TSOA existence. We just manually register BazService in IoC container upon application startup in server.ts