Setting up your IDE
You can use either Metals with your favorite editor (VS Code, Neovim, Sublime) or IntelliJ IDEA for Scala to work on the Scala 3 codebase. There are however a few additional considerations to take into account.
Bootstrapping Projects
The sbt build for dotty implements bootstrapping within the same build, so each component has two projects:
sbt:scala3> projects
...
[info] scala3-compiler
[info] scala3-compiler-bootstrapped
...
These duplicated projects can be confusing and cause issues in IDEs.
Metals
When using Metals, the -bootstrapped projects are not exported by default. Normally this is fine, but if you're working on certain modules like scaladoc you'll actually want these modules exported. In order to achieve this you'll first want to ensure you're using sbt as your build server instead of the default Bloop. You can achieve this with the Metals: Switch Build Server command and then choosing sbt. Once you do this, you'll want to find and change the following under commonBootstrappedSettings which is found in the Build.scala file.
- bspEnabled := false,
+ bspEnabled := true,
IntelliJ
In IntelliJ IDEA, we recommend importing the dotty codebase through BSP, then the -bootstrapped projects are not exported.