Rhai Analyzer
Rhai language support for Visual Studio Code, powered by the rhai-analyzer language server.
Overview
Rhai Analyzer brings editor tooling for the Rhai scripting language to Visual Studio Code. The extension starts and manages rhai-lsp, contributes Rhai language assets to VS Code, and exposes language features backed by the Rust analysis engine.
The extension is designed to stay aligned with real Rhai syntax and semantics rather than a simplified editor-specific dialect.
Features
- Semantic diagnostics for Rhai source files
- Hover information and signature help
- Go to definition, find references, and rename
- Code completion, including project and module symbols
- Inlay hints for variables, parameters, and return types
- Document formatting powered by the shared
rhai-fmt formatter
- Semantic tokens, document symbols, workspace symbols, and folding ranges
- Call hierarchy, document highlights, and code actions
- Baseline syntax highlighting, Rhai snippets, and Markdown fenced-code highlighting
Getting Started
The extension activates automatically for .rhai files.
In a packaged installation, the extension looks for a bundled rhai-lsp binary inside the extension. For local development or custom deployments, you can also point the extension at an explicit server executable through rhai.server.path.
Extension Settings
The extension contributes the following settings under the rhai namespace:
| Setting |
Description |
rhai.server.path |
Absolute path to a custom rhai-lsp executable. |
rhai.server.transport |
Transport used to communicate with the language server: stdio or tcp. |
rhai.server.tcpAddress |
TCP endpoint used when rhai.server.transport is set to tcp. |
rhai.server.logLevel |
Log level passed to rhai-lsp when the extension launches it. |
rhai.trace.server |
VS Code LSP trace level for protocol inspection. |
rhai.inlayHints.variables |
Show inferred type hints for local variables. |
rhai.inlayHints.parameters |
Show inferred type hints for function and closure parameters. |
rhai.inlayHints.returnTypes |
Show inferred return type hints for functions and closures. |
rhai.format.maxLineLength |
Preferred maximum line length for formatting. |
rhai.format.trailingCommas |
Preserve trailing commas in expanded lists and containers. |
rhai.format.finalNewline |
Ensure formatted files end with a trailing newline. |
rhai.format.containerLayout |
Prefer single-line, multi-line, or automatic container layout decisions. |
rhai.format.importSortOrder |
Preserve source order or sort contiguous import sections by module path. |
Project-level formatter configuration can also be provided through rhai.toml. The shared formatter configuration surface is documented in the workspace RHAI_TOML.md file.
Development
Build the language server:
cargo build -p rhai-lsp
Install dependencies and build the extension:
cd clients/vscode
npm install
npm run build
Open clients/vscode in Visual Studio Code and press F5.
The extension host launch configuration rebuilds both the VS Code client bundle and rhai-lsp.
Packaging
To produce a local VSIX package and build the release rhai-lsp binary as part of the process:
cd clients/vscode
npm install
npm run package:local
For CI and other prebuilt packaging flows, stage the server bundle first and package it afterwards:
cd clients/vscode
npm run prepare-server
npm run package
The package script only packages the currently staged clients/vscode/server bundle and will not rebuild or restage rhai-lsp.
This split avoids overwriting a preassembled multi-target server bundle during the packaging step. It is especially important in CI, where multiple platform binaries may already have been downloaded into a staging directory before packaging.
To clear generated extension artifacts and staged server bundles:
cd clients/vscode
npm run clean
The packaged extension is written to:
clients/vscode/.artifacts/rhai-analyzer.vsix
You can then install it through the Visual Studio Code command:
Extensions: Install from VSIX...
Status
Rhai Analyzer is under active development. The current extension is suitable for local use and testing, while language coverage, packaging workflows, and release distribution continue to improve.
This is still a fast-moving MVP release. Large parts of the codebase have not yet gone through the level of detailed review and hardening expected from a mature production extension, so some code paths may still have suboptimal performance characteristics or panic in edge cases.
