CRBasic for VS Code (opencrbasic)

A VS Code client for the opencrbasic language server (python -m opencrbasic.lsp). It registers the crbasic language for CRBasic programs and starts the server over stdio. The server provides diagnostics, hover, completion, signature help, outline, folding, navigation, semantic tokens, rename, formatting, quick fixes and the syntax highlighting of the CR6 catalog.

Setup, every setting with its default, the feature list with its limits, the help directory and the host-tested status are in the user guide of opencrbasic. MIT licensed; not affiliated with Campbell Scientific.

Quick start

1. Install the server: uv tool install "opencrbasic[lsp]" (or pip install "opencrbasic[lsp]" into any Python 3.15+ environment).
2. Install this extension from the Marketplace ("CRBasic (opencrbasic)").
3. Set opencrbasic.pythonPath to that environment's interpreter, as an absolute path. With uv tool, that is $(uv tool dir)/opencrbasic/bin/python.

Requirements

• Node.js with npm (the macOS host run at 1b01311d used Node 26.0.0 and npm 11.12.1) and VS Code 1.95 or newer (the host run used VS Code 1.141.0).
• A Python 3.15+ environment with opencrbasic[lsp]; see section 2 of the user guide.
• opencrbasic.pythonPath set to that environment's interpreter, as an absolute path.

Build and test

npm ci
npm run lint
npm test
uvx pre-commit install   # lint, compile and file hygiene before each commit

npm run lint runs ESLint with typescript-eslint; npm test compiles (tsc --strict), then runs the node:test unit tests in src/test/: the launch-argument builder, the settings mapping, the configuration-change decisions and the client stop. They do not start VS Code.

Package and install

npm ci
npm run package
code --install-extension opencrbasic-<version>.vsix

npm run package compiles, then writes opencrbasic-<version>.vsix into this directory. The .vsix is git-ignored and must not be committed. The package holds out/, syntaxes/, language-configuration.json, package.json, this README and the runtime dependency vscode-languageclient with its dependencies. It excludes src/, the tests and .vscode/. CI builds the same package on every push and publishes it to the Visual Studio Marketplace from main (see "Releasing").

The extension does not include the Python server. Install opencrbasic with the lsp extra and set opencrbasic.pythonPath to that interpreter. Installing the VSIX into VS Code is a host check; it has not been run in the build container.

Development launch

1. Open this repository in VS Code and run npm run compile (or npm run watch).
2. Press F5 ("Run Extension"). This opens an Extension Development Host with no folder.
3. Open a folder with CRBasic programs, for example a checkout of firnmelt-station, then open a CRBasic file.

When the interpreter imports opencrbasic from another checkout, for example a git worktree, set opencrbasic.serverEnv to {"PYTHONPATH": "<checkout>/src"}. Run opencrbasic: Restart Server after changing server code.

Settings

Settings are declared in package.json and documented in section 3 of the user guide. The ones that restart the server are pythonPath, serverArgs and serverEnv; the rest reach the running server without a restart.

Highlighting and limitations

• syntaxes/crbasic.tmLanguage.json is generated from the CR6 catalog by opencrbasic's tools/gen_grammar.py, run in an open-crbasic checkout next to this one. Do not edit it by hand.
• Tested and claimed for macOS only (VS Code 1.141.0), at the revisions in section 8 of the user guide: language features, rename, formatting, quick fixes and watched files including their visual checks, the packaged .vsix, inlay hints and the output commands. Windows and Linux are untested and not claimed.

Releasing

A push to main that passes CI publishes the extension to the Visual Studio Marketplace when the version in package.json has not been published yet (vsce publish --skip-duplicate); bump it with npm version patch --no-git-tag-version in the change to release. Publishing uses Marketplace Trusted Publishing (OIDC) from the marketplace GitHub environment; no token is stored. The extension's version is independent of the opencrbasic package version.