clippy-advanced - Advanced Clippy Configuration

Advanced Clippy configuration for comprehensive Rust linting, including custom rules, lint categories, disallowed methods, and IDE integration.

When to Use This Skill

Use this skill when...	Use another tool instead when...
Configuring Clippy lint rules	Formatting code (use rustfmt)
Setting up CI linting for Rust	Building/compiling (use cargo build)
Customizing clippy.toml	Running tests (use cargo test)
Enforcing code standards	Managing dependencies (use cargo add)

Installation

# Clippy is included with rustup
rustup component add clippy

# Verify installation
cargo clippy --version

# Update clippy with rust toolchain
rustup update

Basic Usage

# Run clippy on current project
cargo clippy

# Run on all targets (lib, bins, tests, examples, benches)
cargo clippy --all-targets

# Run with all features enabled
cargo clippy --all-features

# Run on workspace
cargo clippy --workspace --all-targets --all-features

# Show detailed lint explanations
cargo clippy -- -W clippy::all -A clippy::pedantic

# Treat warnings as errors
cargo clippy -- -D warnings

Lint Categories

Category	Purpose	Default
`clippy::correctness`	Likely bugs	Deny
`clippy::complexity`	Overly complex code	Warn
`clippy::perf`	Performance issues	Warn
`clippy::style`	Code style	Warn
`clippy::suspicious`	Code that looks wrong	Warn
`clippy::pedantic`	Opinionated style	Off
`clippy::restriction`	Opt-in constraints	Off
`clippy::nursery`	Experimental	Off
`clippy::cargo`	Cargo.toml issues	Off

Recommended Cargo.toml Configuration

[workspace.lints.clippy]
# Deny correctness issues (likely bugs)
correctness = "deny"
complexity = "warn"
perf = "warn"
style = "warn"
suspicious = "warn"

# Enable pedantic but allow some noisy lints
pedantic = "warn"
must_use_candidate = "allow"
missing_errors_doc = "allow"

# Enable some restriction lints selectively
clone_on_ref_ptr = "warn"
dbg_macro = "warn"
print_stdout = "warn"
todo = "warn"
unimplemented = "warn"
unwrap_used = "warn"

# Enable nursery lints (experimental)
use_self = "warn"

clippy.toml Essential Settings

Create clippy.toml in project root for thresholds and disallowed items:

cognitive-complexity-threshold = 15
too-many-lines-threshold = 100
too-many-arguments-threshold = 5

disallowed-methods = [
  { path = "std::env::var", reason = "Use std::env::var_os for better Unicode handling" },
  { path = "std::process::exit", reason = "Use Result propagation instead" },
]

disallowed-names = ["foo", "bar", "baz"]

Lint Suppression

// Function-level
#[allow(clippy::too_many_arguments)]
fn complex_function(a: i32, b: i32, c: i32, d: i32, e: i32, f: i32) {}

// Module-level (src/lib.rs)
#![warn(clippy::all)]
#![warn(clippy::pedantic)]
#![deny(clippy::unwrap_used)]
#![allow(clippy::module_name_repetitions)]

// Inline
#[allow(clippy::cast_possible_truncation)]
let x = value as u8;

Agentic Optimizations

Context	Command
CI strict	`cargo clippy --workspace --all-targets -- -D warnings`
JSON output	`cargo clippy --message-format=json`
Compact errors	`cargo clippy --message-format=short`
Quick check	`cargo clippy --message-format=short -- -D warnings`
Pedantic check	`cargo clippy -- -W clippy::pedantic -D clippy::correctness`

Quick Reference

Command-Line Flags

Flag	Description
`--all-targets`	Check lib, bins, tests, examples, benches
`--all-features`	Enable all features
`--workspace`	Check entire workspace
`--message-format=json`	JSON output for tooling
`--message-format=short`	Compact error format
`-- -D warnings`	Treat warnings as errors
`-- -W clippy::pedantic`	Enable pedantic lints
`-- -A clippy::lint_name`	Allow specific lint

Lint Levels

Level	Attribute	Effect
Allow	`#[allow(...)]`	Suppress lint
Warn	`#[warn(...)]`	Show warning
Deny	`#[deny(...)]`	Compile error

References

For detailed configuration examples, CI integration, IDE setup, and best practices, see REFERENCE.md.