Trait ToProblem 

pub trait ToProblem: Display {
    // Required method
    fn to_problem(&self) -> ProblemDetails;

    // Provided method
    fn render(&self, format: OutputFormat) -> String { ... }
}

Implemented by each crate’s own error enum to map it to a ProblemDetails envelope.

Keeps error enums scoped to each crate’s own failure modes (this workspace has no shared top-level error type) while sharing one envelope shape across the workspace. Requires std::fmt::Display (already derived by thiserror::Error on every implementing enum) so the default ToProblem::render can reuse it for pretty output.

Examples

use mif_problem::{Applicability, CodeAction, ProblemDetails, ProblemMeta, SuggestedFix, ToProblem};

#[derive(Debug, thiserror::Error)]
enum ExampleError {
    #[error("input was empty")]
    Empty,
}

impl ToProblem for ExampleError {
    fn to_problem(&self) -> ProblemDetails {
        let meta = ProblemMeta {
            slug: "empty-input",
            version: "v1",
            title: "Empty input",
            status: 400,
            exit_code: 2,
        };
        meta.into_details(env!("CARGO_PKG_NAME"), self.to_string())
            .with_suggested_fix(SuggestedFix::new(
                "Supply a non-empty input.",
                Applicability::MaybeIncorrect,
            ))
            .with_code_action(CodeAction::new(
                "Provide a value",
                "quickfix",
                Applicability::MaybeIncorrect,
            ))
    }
}

let err = ExampleError::Empty;
assert_eq!(err.to_problem().status, 400);
assert_eq!(err.render(mif_problem::OutputFormat::Pretty), "Error: input was empty");

Required Methods

fn to_problem(&self) -> ProblemDetails

Maps self to a fully-populated ProblemDetails envelope.

Provided Methods

fn render(&self, format: OutputFormat) -> String

Renders self for the given OutputFormat.

Pretty rendering is Error: {self}, matching this workspace’s existing mif-cli/mif-mcp error text. JSON rendering is the compact RFC 9457 envelope from ToProblem::to_problem.

Arguments

• format - The format to render.

Returns

The rendered error string (without a trailing newline).

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors