Ferrox Errors (ferrox-errors)

ferrox-errors defines the unified error handling strategy for Ferrox applications. It provides the standard AppError enum and implements Axum's IntoResponse trait to automatically convert application errors into consistent JSON responses with standard HTTP status codes.

Rationale & Design

In enterprise Rust microservices, unhandled errors or raw Result<T, E> returns can leak internal stack traces or produce inconsistent JSON structures for frontend consumers. ferrox-errors solves this by forcing all service layers to emit AppError, which serializes into predictable { "status": u16, "message": String } responses.

Key Features

• 🚫 AppError Enum: Structured variants for NotFound, ValidationError, Unauthorized, InternalError, and DatabaseError.
• ⚡ Axum IntoResponse: Seamless integration with Axum route handlers without manual status code mappings.
• 🔒 Security Sanitization: Internal server errors and database errors are logged privately while safe generic error messages are exposed to clients.

Example Usage

use ferrox_errors::{AppError, ErrorResponse};
use axum::response::IntoResponse;

fn find_user(id: u64) -> Result<String, AppError> {
    if id == 0 {
        Err(AppError::NotFound("User not found".into()))
    } else {
        Ok("Alice".into())
    }
}