A high-performance Ruby Language Server written in Rust, delivering fast and accurate code navigation, syntax highlighting, and intelligent code insights for Ruby developers across entire projects.

• Go to Definition

  • Modules ✅
  • Classes ✅
  • Constants ✅
  • Local variables ✅
  • Methods (limited) 🚧
  • Instance/Class/Global variables 🚧

• Find References

  • Modules ✅
  • Classes ✅
  • Constants ✅
  • Local variables ✅
  • Methods (limited) 🚧

• Hover information ❌
• Code actions / Quick fixes ❌
• Rename support ❌
• Formatting integration (Rubocop) ❌
• Full type inference ❌
• Meta-programming support ❌
• Run/Debug support ❌

1. Install the extension from the VS Code marketplace
2. Open a Ruby project folder in VS Code
3. The LSP will automatically:
   • Start up and index your workspace
   • Provide language features as you type
   • Support navigation across your entire project

• VS Code 1.86.0 or later
• Ruby project (single file or workspace)

The extension supports the following settings:

• ruby-fast-lsp.codeLensModulesEnabled - Enable/disable code lens for module mixin counts (default: true)

Ruby Fast LSP is designed for speed:

• Written in Rust for native performance
• Incremental indexing on file changes
• Efficient symbol lookups using trie data structures
• Optimized for large codebases

• Method references may be incomplete in some cases
• Large workspaces may take time to index initially
• Some edge cases in Ruby syntax may not be fully supported yet

cargo build --release

# Run all tests
cargo test

# Run simulation tests (property-based fuzzing)
cargo test sim --release

# Run soak test (overnight fuzzing, Ctrl+C to stop)
cargo test soak --release -- --nocapture --ignored

See docs/testing.md for detailed testing documentation.

• src/ - Main LSP server implementation
• src/capabilities/ - LSP feature handlers (completion, definitions, etc.)
• src/indexer/ - Project indexing and symbol management
• src/type_inference/ - Type inference engine
• src/test/simulation/ - Property-based simulation tests
• crates/rbs-parser/ - RBS type signature parser
• vsix/ - VS Code extension packaging

Please report any issues or feature requests on our GitHub repository.

MIT