rust-lsp

rust-lsp

A Claude Code plugin providing comprehensive Rust development support through:

• rust-analyzer LSP integration for IDE-like features
• 16 automated hooks for code quality, security, and analysis
• Cargo tool ecosystem integration

Quick Setup

# Run the setup command (after installing the plugin)
/setup

Or manually:

# Install rust-analyzer
rustup component add rust-analyzer

# Install nightly toolchain (required for some tools)
rustup toolchain install nightly

# Install all cargo tools
cargo install cargo-audit cargo-deny cargo-outdated cargo-machete \
              cargo-semver-checks cargo-geiger cargo-expand cargo-bloat \
              cargo-mutants && \
cargo +nightly install cargo-udeps

Features

LSP Integration

The plugin configures rust-analyzer for Claude Code via .lsp.json:

{
    "rust": {
        "command": "rust-analyzer",
        "args": [],
        "extensionToLanguage": { ".rs": "rust" },
        "transport": "stdio"
    }
}

Capabilities:

• Go to definition / references
• Hover documentation
• Code actions and quick fixes
• Workspace symbol search
• Real-time diagnostics

Automated Hooks

All hooks run afterWrite and are configured in hooks/hooks.json.

Core Rust Hooks

Hook	Trigger	Description
rust-format-on-edit	**/*.rs	Auto-format with rustfmt
rust-check-on-edit	**/*.rs	Compile check with cargo check
rust-clippy-on-edit	**/*.rs	Lint with cargo clippy
rust-test-compile-on-edit	**/*.rs	Verify tests compile (cargo test --no-run)

Documentation & Quality

Hook	Trigger	Description
rust-doc-check	**/src/**/*.rs	Check rustdoc for warnings/errors
rust-todo-fixme	**/*.rs	Surface TODO/FIXME/XXX/HACK comments
rust-unsafe-detector	**/*.rs	Flag unsafe blocks for review

Dependency Management

Hook	Trigger	Tool Required	Description
rust-audit	**/Cargo.lock	cargo-audit	CVE vulnerability scanning
rust-deny-check	**/Cargo.toml	cargo-deny	License/security policy enforcement
rust-outdated	**/Cargo.toml	cargo-outdated	Check for outdated dependencies
rust-machete	**/Cargo.toml	cargo-machete	Fast unused dependency detection
rust-unused-deps	**/Cargo.toml	cargo-udeps	Thorough unused dependency check (nightly)

Advanced Analysis

Hook	Trigger	Tool Required	Description
rust-semver-check	**/src/lib.rs	cargo-semver-checks	API compatibility verification
rust-geiger	**/Cargo.toml	cargo-geiger	Unsafe code ratio in dependencies

Contextual Hints

Hook	Trigger	Description
rust-mutants-hint	**/src/**/*.rs	Suggests mutation testing when available
rust-bloat-hint	**/Cargo.toml	Suggests binary size analysis
rust-expand-hint	**/*.rs	Suggests macro expansion when macros detected
rust-bench-hint	**/*.rs	Suggests benchmark run when benchmarks detected

Other

Hook	Trigger	Description
markdown-lint-on-edit	**/*.md	Lint markdown files

Required Tools

Core (Included with Rust)

Tool	Installation	Purpose
rustfmt	rustup component add rustfmt	Code formatting
clippy	rustup component add clippy	Linting
rust-analyzer	rustup component add rust-analyzer	LSP server

Recommended Cargo Extensions

Tool	Installation	Purpose
cargo-audit	cargo install cargo-audit	Security vulnerability database
cargo-deny	cargo install cargo-deny	License and security policy
cargo-outdated	cargo install cargo-outdated	Dependency freshness
cargo-machete	cargo install cargo-machete	Unused dependencies (fast)

Optional Cargo Extensions

Tool	Installation	Purpose
cargo-udeps	cargo +nightly install cargo-udeps	Unused dependencies (thorough)
cargo-semver-checks	cargo install cargo-semver-checks	Semver compatibility
cargo-geiger	cargo install cargo-geiger	Unsafe code metrics
cargo-expand	cargo install cargo-expand	Macro expansion
cargo-bloat	cargo install cargo-bloat	Binary size analysis
cargo-mutants	cargo install cargo-mutants	Mutation testing

Commands

/setup

Interactive setup wizard for configuring the complete Rust development environment.

What it does:

1. Verifies Rust toolchain - Checks rustup and cargo installation
2. Installs rust-analyzer - LSP server for IDE features
3. Installs nightly toolchain - Required for cargo-udeps
4. Installs cargo tools - All 10 recommended extensions
5. Validates LSP config - Confirms .lsp.json is correct
6. Initializes deny.toml - Sets up security/license policy (if needed)
7. Verifies hooks - Confirms hooks are properly loaded

Usage:

/setup

Quick install command (from the wizard):

rustup component add rust-analyzer && \
rustup toolchain install nightly && \
cargo install cargo-audit cargo-deny cargo-outdated cargo-machete \
              cargo-semver-checks cargo-geiger cargo-expand cargo-bloat \
              cargo-mutants && \
cargo +nightly install cargo-udeps

Command	Description
/setup	Full interactive setup for LSP and all cargo tools

Configuration

deny.toml

If using cargo-deny, initialize configuration:

cargo deny init

This creates deny.toml for configuring:

• Allowed/denied licenses
• Security advisory settings
• Duplicate dependency rules

Customizing Hooks

Edit hooks/hooks.json to:

• Disable hooks by removing entries
• Adjust output limits (head -N)
• Modify matchers for different file patterns
• Add project-specific hooks

Example - disable a hook:

{
    "name": "rust-geiger",
    "enabled": false,
    ...
}

Project Structure

rust-lsp/
├── .claude/
│   └── commands/
│       └── setup.md          # /setup command
├── .claude-plugin/
│   └── plugin.json           # Plugin metadata
├── .lsp.json                  # rust-analyzer configuration
├── hooks/
│   └── hooks.json            # 16 automated hooks
├── CLAUDE.md                  # Project instructions
└── README.md                  # This file

Troubleshooting

rust-analyzer not starting

1. Ensure Cargo.toml exists in project root
2. Run cargo check to generate initial build artifacts
3. Verify installation: rust-analyzer --version
4. Check LSP config: cat .lsp.json

cargo-udeps fails

Requires nightly toolchain:

rustup toolchain install nightly
rustup component add rust-src --toolchain nightly
cargo +nightly udeps

cargo-deny errors

Initialize and update:

cargo deny init
cargo deny fetch

Hooks not triggering

1. Verify hooks are loaded: cat hooks/hooks.json
2. Check file patterns match your structure
3. Ensure required tools are installed (command -v cargo-audit)

Too much output

Reduce head -N values in hooks.json for less verbose output.

License

MIT