Ra

rust-analyzer CLI Skill

You have access to rust-analyzer's powerful CLI for Rust code analysis. Use the Bash tool to run these commands.

Invocation

The user invokes this skill with /ra <command> [args]. Parse $ARGUMENTS to determine which operation to perform.

Arguments received: $ARGUMENTS

Commands Reference

diag or diagnostics — Project Diagnostics

Run compiler diagnostics on a Rust project.

rust-analyzer diagnostics <project-path>

Project path: Find the nearest Cargo.toml from the current working directory, or use a path specified in arguments.

Example output interpretation: Errors and warnings with file locations and messages.

refs or unresolved — Unresolved References

Find all unresolved references in a project (missing imports, undefined names, etc.).

rust-analyzer unresolved-references <project-path>

Useful for: Finding missing imports, typos in identifiers, incomplete refactors.

stats — Analysis Statistics

Get analysis statistics for a project.

rust-analyzer analysis-stats <project-path>

Shows: Module count, function count, type analysis coverage, macro expansion stats.

search <pattern> — Structural Code Search

Search for structural code patterns using rust-analyzer's pattern matching. Operates on the current working directory.

rust-analyzer search '<pattern>' 2>&1

Note: Output shows matching code snippets without file paths. Use grep after to locate specific matches if needed.

Pattern syntax:

• $name matches any single AST node and binds it to name
• $name:expr matches expressions
• $name:stmt matches statements
• $name:ty matches types
• $name:pat matches patterns
• $name:item matches items (functions, structs, etc.)
• $name:path matches paths
• $$name matches zero or more AST nodes (like regex *)

Examples:

• $a.unwrap() — find all .unwrap() calls
• if let Some($x) = $y { $$ } — find if-let-some patterns
• fn $name($args) -> Result<$ok, $err> — find functions returning Result
• $receiver.map($f).unwrap_or($default) — find map+unwrap_or chains

ssr <rule> — Structural Search and Replace

Perform structural search-and-replace transformations.

rust-analyzer ssr '<pattern> ==>> <replacement>'

Note: This outputs the transformation but does NOT modify files. Review output and apply manually if desired.

Examples:

• $a.unwrap() ==>> $a? — preview replacing unwrap with ?
• Option::Some($x) ==>> Some($x) — simplify Option::Some
• $a.map($f).unwrap_or($d) ==>> $a.map_or($d, $f) — use map_or

symbols — Parse Symbols from Stdin

Parse Rust code from stdin and list symbols.

echo '<rust-code>' | rust-analyzer symbols

Or read a file:

cat <file.rs> | rust-analyzer symbols

Execution Strategy

1. Parse the command from $ARGUMENTS:

   • First word is the command (diag, refs, stats, search, ssr, symbols)
   • Remaining words are command-specific arguments

2. Locate the project:

   • If a path is provided, use it
   • Otherwise, find nearest Cargo.toml from current working directory
   • For workspace with multiple crates, use the workspace root

3. Run the command using Bash tool

4. Interpret output:

   • For diagnostics: summarize errors/warnings by severity and file
   • For search/ssr: show matches with context
   • For stats: highlight interesting metrics

5. Suggest follow-ups when relevant:

   • After diagnostics: offer to help fix specific issues
   • After search: offer to apply transformations or refactor

Finding the Project Root

Use this to locate the Rust project:

# Find nearest Cargo.toml
cargo locate-project --message-format=plain 2>/dev/null | xargs dirname

Or for workspace root:

cargo metadata --no-deps --format-version=1 2>/dev/null | jq -r '.workspace_root'

Error Handling

• If rust-analyzer isn't installed: suggest rustup component add rust-analyzer
• If no Cargo.toml found: ask user to specify project path
• If pattern syntax is wrong: explain pattern syntax with examples

Examples of Full Invocations

User: /ra diag → Run diagnostics on current project

User: /ra refs acme/myapp → Find unresolved references in myapp project

User: /ra search '$a.unwrap()' → Find all .unwrap() calls in current project

User: /ra ssr '$a.unwrap() ==>> $a?' → Preview replacing unwrap with ? operator

User: /ra stats → Show analysis statistics for current project

Source: kungfuchicken/pi-agent-container — distributed by TomeVault.