fix-clippy-warnings

# Fix Clippy Warnings This skill guides you through the proper handling of Rust Clippy warnings in the Torrust Tracker project. ## Clippy Philosophy **Always prefer fixing clippy warnings with the suggested approach** rather than adding `#[allow(...)]` attributes. Clippy warnings are designed to improve code quality, readability, and maintainability. ## When to Apply Clippy Suggestions ### ✅ Apply Suggested Fixes When clippy suggests a specific code change that improves quality: - Use `as_chunks::<N>()` instead of `chunks_exact(N)` (as we did in SI-4) - Use `#[allow(clippy::explicit_iter_loop)]` instead of `iter()` when it's more concise - Apply any other suggestion that improves code quality ### ⚠️ When to Add Allowances Only add `#[allow(...)]` when: 1. The suggestion is **not applicable** to the specific use case 2. The suggestion would **break existing functionality** or API 3. The suggestion is **temporarily ignored** during a refactoring phase 4. The suggestion is **not yet supported** in the current Rust version ## How to Document Exceptions When adding or modifying `#[allow(clippy::...)]` or `#[expect(clippy::...)]` attributes, use Rust's native `reason` parameter. The prospective Rust validator checks changed attributes against the branch merge base, so existing allows remain the separate remediation scope of #2158. ```rust #[allow( clippy::unnecessary_wraps, reason = "Temporary parser compatibility shim; remove when #2158 is complete." )] ``` The reason must be specific. A temporary reason must also contain either a stable issue reference such as `#2158` or a non-empty `remove when`, `remove after`, `remove by`, `removed when`, `removed after`, `removed by`, or `until` condition. The validator treats `temporary`, `temporarily`, `TODO`, `for now`, and `workaround` as temporary wording and normalizes whitespace before checking the condition. Do not enable `clippy::allow_attributes_without_reason` workspace-wide until #2158 has remediated the historical attributes that lack native reasons. It is the correct eventual compiler-aware enforcement mechanism, but enabling it now would violate this issue's prospective-baseline scope. For a temporary item-level suppression, prefer `#[expect(..., reason = "...")]` when it is useful to learn that the underlying lint no longer fires. Do not force `expect` for crate-level policy. The validator also checks changed `cfg_attr(..., allow(clippy::...))` and `cfg_attr(..., expect(clippy::...))` controls. Attributes written inside a `macro_rules!` token body are not visited by the Rust AST and are out of scope for this prospective check; do not use macros to conceal a lint suppression. For example: ```rust #[expect( clippy::unnecessary_wraps, reason = "Temporary parser compatibility shim; remove when #2158 is complete." )] fn parse_announce_response(data: &[u8]) -> Result<Response, ParseError> { // implementation } ``` ## Common Clippy Patterns ### Pattern 1: `chunks_exact` → `as_chunks` **Before:** ```rust for chunk in bytes.chunks_exact(6) { // process 6-byte chunks } ``` **After:** ```rust let (chunks, remainder) = bytes.as_chunks::<6>(); if !remainder.is_empty() { return Err(ParseError::InvalidChunkSize); } for chunk in chunks.iter() { // process 6-byte chunks } ``` ### Pattern 2: Explicit Iterator Loop **Before:** ```rust for item in items.iter() { // process item } ``` **After:** ```rust for item in &items { // process item } ``` ## Clippy Workflow 1. **Identify the warning**: Run `linter clippy` to see specific clippy errors 2. **Apply suggestion**: Try the suggested fix first 3. **Verify functionality**: Ensure the change doesn't break existing behavior 4. **Document exceptions**: Use the native `reason = "..."` parameter for changed Clippy allows 5. **Run full linters**: Confirm `linter all` passes ## Related Skills - [`run-linters`](../../git-workflow/run-linters/SKILL.md) - Run all code quality checks - [`commit-changes`](../../git-workflow/commit-changes/SKILL.md) - Commit changes with proper conventions