This is an example of a full-stack application with the following features:

• Scala 3 on both frontend and backend
• Laminar as a frontend library
• Http4s as a backend HTTP server library
• Shared code with protocol definitions
• Gzip compression on the server side
• Docker packaging of the full application
• Tests for the client with simulated DOM using jsdom

Note: this is a very basic setup, for a more complicated template (with Postgres, API spec using Smithy, etc.) please see Smithy4s Fullstack template

Additionally, you can check out my blog series about fullstack Scala 3:

• Twotm8 - building and deploying a full-stack Scala application using Scala Native and Scala.js

• Smithy4s - building and deploying a full-stack Scala app with Smithy4s and Scala.js

Note: this version of the template uses the latest and greatest from Cats Effect, http4s, Scala, etc. If you would like, please see the last commit that referenced old versions of the libraries. Apart from Scala 3 (which is still wonky around IntelliJ support), I highly recommend sticking with the latest versions of the libraries.

Run in SBT (uses fast JS compilation, not optimized):

sbt> ~runDev

And open http://localhost:9000/frontend

This will restart the server on any changes: shared code, client/server, assets.

It is a prerequisite to have jsdom installed, in order for the frontend tests to run. Proposal:

yarn add jsdom

Then move into an sbt console and run tests as normal

Run in SBT (uses full JS optimization):

sbt> ~runProd

sbt> backend/docker:publishLocal

Will publish the docker image with fully optimised JS code, and you can run the container:

✗ docker run --rm -p 8080:8080 laminar-http4s-example:0.1.0-SNAPSHOT

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Running server on http://0.0.0.0:8080 (mode: prod)

The interface is fairly simple: