Cursor rule

1---
2description: Rust Tracing Practices
3globs: "**/*.rs"
4alwaysApply: false
5---
6# Rust Tracing Practices
7 
8## Event Recording
9 
10- Use level-specific macros for appropriate visibility: `info!`, `debug!`, `trace!`, `warn!`, `error!`
11- Provide structured data as named arguments to facilitate automated processing and filtering
12- Format log messages consistently, beginning with verbs in present tense
13- Include relevant context through key-value pairs:
14 
15```rust
16tracing::info!(user_id = user.id, action = "login", "User logged in successfully");
17tracing::error!(error = %e, user_id = user.id, "Failed to authenticate user");
18```
19 
20## Instrumentation
21 
22- Apply the `#[tracing::instrument]` attribute to functions to automatically create trace spans
23- Include the `err` parameter to capture error returns in the span
24- Exclude sensitive or large parameters using `skip(password)` or `skip_all`
25- Add custom context fields with `fields(request_id = req.id())`
26 
27```rust
28#[tracing::instrument(level = "debug", err, skip(password), fields(user_id = user.id))]
29async fn authenticate_user(user: &User, password: &[u8]) -> Result<AuthToken, AuthError> {
30    // Implementation
31}
32```
33