Best Practices for Error Handling in Rust Libraries vs Applications

Error Handling

2026-04-17T12:05:42+00:00

Libraries return Result types for error handling, while applications propagate errors to main and panic on unrecoverable failures.

Libraries should return Result<T, E> to let callers handle errors, while applications should propagate errors to main and panic on unrecoverable failures.

// Library: Return Result
pub fn summarize(&self) -> Result<String, MyError> {
    // logic returning Ok or Err
}

// Application: Propagate to main
fn main() -> Result<(), MyError> {
    let article = NewsArticle { /* ... */ };
    let summary = article.summarize()?;
    println!("New article available! {}", summary);
    Ok(())
}