mirror of
https://github.com/open-policy-agent/opa.git
synced 2026-08-26 18:25:06 -06:00
Anders Eknert
1fc46d0684
I deleted the regal.zip file that the script created. I assume that shouldn't be commited? But looking at Johan's "agent" PR, it looks like it was included. We can fix that later though. Signed-off-by: Anders Eknert <anders.eknert@apple.com>
75 lines
2.3 KiB
Markdown
75 lines
2.3 KiB
Markdown
---
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sidebar_position: 10
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sidebar_label: Debugging Rego
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---
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<head>
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<title>Debugging Rego | Regal</title>
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</head>
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# Debugging Rego
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In addition to being a [language server](https://www.openpolicyagent.org/projects/regal/language-server),
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Regal can act as a
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[Debug Adapter](https://microsoft.github.io/debug-adapter-protocol/) for
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supported clients.
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A Debug Adapter is a long running program that can communicate with a debugger
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client, such as Visual Studio Code's debugger, to provide live, step-by-step,
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debugging capabilities for a language.
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<img
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src={require('./assets/dap/animation.gif').default}
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alt="Animation showing the a debugging session in VS Code"/>
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_A debugging session in VS Code_
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## Getting Started
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See the documentation in the Editor Support page for supported clients:
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* [Visual Studio Code](https://www.openpolicyagent.org/projects/regal/editor-support#visual-studio-code)
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* [Neovim](https://www.openpolicyagent.org/projects/regal/editor-support#neovim)
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:::info
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If your evaluation depends on a `data.json` file, please make sure to have
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`.manifest` files to mark your bundles, or
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[configure roots](https://www.openpolicyagent.org/projects/regal/configuration/project-roots)
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in Regal's config.
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:::
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## Features
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The Regal Debug Adapter currently supports the following features:
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### Breakpoints
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Breakpoints allow you to continue execution of a policy until a given point.
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This can be helpful for:
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* Inspection of variables at a given point in time
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* Seeing how many times a given block of Rego code is executed, if at all
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* Avoiding the need to step through code as it's run line by line
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<img
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src={require('./assets/dap/breakpoint.png').default}
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alt="Screenshot of a breakpoint in VS Code"/>
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### Variable Inspection
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Either at a breakpoint or while stepping through code, you can inspect the
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local variables in scope as well as the contents of the global `input` and
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`data` documents.
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`input` will be loaded from `input.json` in the workspace if it exists.
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<img
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src={require('./assets/dap/variables.png').default}
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alt="Variables being inspected during execution in VS Code"/>
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### Print Statements
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Print statements are also supported, these are shown in the debug console:
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<img
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src={require('./assets/dap/print.png').default}
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alt="Print statements shown in the debug output console"/>
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