<head> <title>Debugging Rego | Regal</title> </head>

Debugging Rego

In addition to being a language server, Regal can act as a Debug Adapter for supported clients. A Debug Adapter is a long running program that can communicate with a debugger client, such as Visual Studio Code's debugger, to provide live, step-by-step, debugging capabilities for a language.

A debugging session in VS Code

Getting Started

See the documentation in the Editor Support page for supported clients:

:::info If your evaluation depends on a data.json file, please make sure to have .manifest files to mark your bundles, or configure roots in Regal's config. :::

Features

The Regal Debug Adapter currently supports the following features:

Breakpoints

Breakpoints allow you to continue execution of a policy until a given point. This can be helpful for:

Inspection of variables at a given point in time
Seeing how many times a given block of Rego code is executed, if at all
Avoiding the need to step through code as it's run line by line

Variable Inspection

Either at a breakpoint or while stepping through code, you can inspect the local variables in scope as well as the contents of the global input and data documents.

input will be loaded from input.json in the workspace if it exists.

Print Statements

Print statements are also supported, these are shown in the debug console: