Full stack Scala 3

• Full stack Scala 3
  • Pre-requisites
  • Development workflow
    • Setting up build definitions for Metals
    • Updating protocol definitions
    • Frontend live server
    • Backend live server
    • Packaging as docker container

Frontend: Scala.js and Laminar | Backend: Scala JVM and Http4s | Protocol: Smithy4s | Build system: Scala CLI and Vite | Packaging: Docker | Web server: NGINX

This is an opinionated fullstack scala template:

• The frontend-backend interaction layer is handled through Smithy4s protocol definition – this ensures shared modelling and keeps all definitions in sync, additionally allowing for code sharing between frontend and backend
• Scala CLI is used everywhere. While it doesn't have multi-module support
• NGINX is used as a web server. Using a very configurable and battle-tested server from the very beginning can help implementing more complicated features later as the app grows. We also use it to serve static assets separately from the JVM backend.
• Vite and TailwindCSS are used on the frontend. Bundling a CSS framework can be helpful to get the styling off the ground for people not usually involved in frontend design work.

Pre-requisites

1. Frontend: Node.js and NPM, Scala CLI
2. Backend: Scala CLI
3. Protocol code: Coursier, Scala CLI

Development workflow

Setting up build definitions for Metals

Scala CLI doesn't have any support for multi-module projects, so to make sure we can work with this codebase in Metals we need to generate BSP definitions manually.

1. Run make setup-ide and then cross your fingers that Metals will pick everything up correctly

Updating protocol definitions

1. Make changes to shared/protocol.smithy
2. Run make smithy4s
3. This will regenerate all the code that can be used by both backend and frontend

Frontend live server

1. Run make run-frontend
2. Note that to perform any actions that execute API calls, you need to have backend running as well

Backend live server

1. Run make run-backend
2. This will run the backend server on port 9999 – which is where Vite's frontend tooling expects it to be

Packaging as docker container

1. Run make docker
2. Note that this project is organised as a self-contained docker image - just running docker build . will produce a working docker image. This is particularly useful for services like Fly.io which detect a Dockerfile and can build and deploy app directly from it