This is a Todo-Backend implementation in Scala using Tapir its Http4s interpreter. It is meant as an example project for those wanting to see Tapir in-action.
This class defines a declarative model of the Todo-MVC API using Tapir. Furthermore, it implements a PlainCodec[UUID] allowing us to decode UUIDs directly from path parameters. These endpoints are meant to be hooked up with logic before we can materialize a server
The endpoints are also transformed into OpenAPI models which are then merged into a single model and rendered as .yml.
This .yml file can then be delivered with whatever underlying web library is chosen.
This class contains all the implementations of the different API-endpoints. Furthermore, it maps the endpoints to implementations, exposing a single method: def routes: HttpRoutes[F].
These routes are the final model for building and running the server with endpoints and logic mapped together. Note that the endpoints will be matched in the order they appear in the NonEmptyList.
We use combineK to turn all the implemented routes into a single route. This is possible because Cats implements a SemigroupK instance for Kleisli, and because type HttpRoutes[F[_]] = Kleisli[OptionT[F, ?], Request[F], Response[F]]. The combination works as one would expect -- we try the first route, if the materialized OptionT value is None, we try the next route.
NOTE: To me, this is one of the big wins with Tapir -- you don't lose composability, since interpreting the endpoints simply nets you a composable piece of, e.g., HttpRoutes[F[_]] that you can continue to compose.
Finally, this class also exposes /openapi.yml as well as a /docs which redirects to the index of some swagger-ui resources (which will be provided through web jars, see Main).
This is an IOApp using cats-effect that configures and runs the server using the other classes. Currently, it simply binds to 127.0.0.1:8080. It also exposes static resources from the swagger-ui webjar using http4s' built in support.
Place yourself in the root folder and issue sbt run. Once the server is up, you can go to this page and run the test suite against your running app. This is possible because tapir.todomvc.Main sets up the neccessary CORS configuration.
After running the app, you can visit the documentation by going to http://127.0.0.1:8080/docs.
To view the raw OpenAPI specification, go to http://127.0.0.1:8080/docs/docs.yaml.