Setting Up Your IDE

Download IntelliJ Community
Install and run it
Install the Scala Plugin - just search and install from within IntelliJ.
Important: open sbt in your local joern repository, run compile and keep it open - this will allow us to use the BSP build in the next step
Back to IntelliJ: open project: select your local joern clone: select to open as BSP Project (i.e. not sbt project!)
Await the import and indexing to complete, then you can start, e.g. Build -> Build project or run a test

Pro tip: Scala 3 support is limited and opting for Nightly builds is highly recommended.

Install VSCode and Docker
Install the plugin ms-vscode-remote.remote-containers
Open Joern project folder in VSCode Visual Studio Code detects the new files and opens a message box saying: Folder contains a Dev Container configuration file. Reopen to folder to develop in a container.
Select the Reopen in Container button to reopen the folder in the container created by the .devcontainer/Dockerfile file
Switch to scalameta.metals sidebar in VSCode, and select import build in BUILD COMMANDS
After import build succeeds, you are ready to start writing code for Joern