100 Exercises To Learn Rust - 5.12 ThisError 풀기

문제

// TODO: Implement the `Error` trait for `TicketNewError` using `thiserror`.
//   We've changed the enum variants to be more specific, thus removing the need for storing
//   a `String` field into each variant.
//   You'll also have to add `thiserror` as a dependency in the `Cargo.toml` file.

풀이

Cargo.toml의 [dependencies]에 ThisError="2.0.12"와 같이 추가하고, TicketNewError를 다음과 같이 수정한다.

#[derive(thiserror::Error, Debug, )]
enum TicketNewError {
    #[error("Title cannot be empty")]
    TitleCannotBeEmpty,
    #[error("Title cannot be longer than 50 bytes")]
    TitleTooLong,
    #[error("Description cannot be empty")]
    DescriptionCannotBeEmpty,
    #[error("Description cannot be longer than 500 bytes")]
    DescriptionTooLong,
}