masterror-derive 0.10.0

Derive macros for masterror
Documentation

masterror-derive

REUSE status

Procedural macros that power masterror's #[derive(Error)]. The derive generates ergonomic std::error::Error and Display implementations together with seamless integration into masterror's domain-centric AppError type.

Tip: Depend on the masterror crate in application code and import the macros from there (use masterror::Error;). This standalone crate is published to make cargo install/cargo package flows happy and to support advanced macro integrations.

Quick start

[dependencies]
masterror = "0.10"

use masterror::{AppError, Error};

#[derive(Error)]
#[error(display = "failed to parse payload: {source}")]
#[app_error(kind = "BadRequest")]
pub struct PayloadInvalid {
    #[source]
    pub source: serde_json::Error,
}

fn parse(input: &str) -> Result<(), AppError> {
    serde_json::from_str::<serde_json::Value>(input)
        .map(|_| ())
        .map_err(PayloadInvalid::from)
}

The derive implements Display, std::error::Error, and conversion glue so you can return rich AppError values with a single ?.

Supported attributes

  • #[error(display = ...)] – formats the error message using captured fields.
  • #[source] / #[from] – wires source error propagation and conversion.
  • #[backtrace] – exposes an optional captured Backtrace.
  • #[app_error(...)] – configures how the error maps into AppError (kind, HTTP status, telemetry).
  • #[provide(...)] – attaches structured telemetry providers that surface typed context (IDs, domains, tenant information) through tracing layers.

See the main masterror README for an end-to-end guide and advanced examples covering templated display strings, telemetry providers and OpenAPI/schema integrations.

License

Licensed under either of

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be licensed as above, without any additional terms or conditions.