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#![cfg(feature="std")]
use snafu::prelude::*;
#[derive(Debug, Snafu)]
enum InnerError {
Boom,
}
fn inner() -> Result<(), InnerError> {
Ok(())
}
mod enabling {
use super::*;
#[derive(Debug, Snafu)]
enum Error {
NoArgument {
#[snafu(source)]
cause: InnerError,
},
ExplicitTrue {
#[snafu(source(true))]
cause: InnerError,
},
FromImpliesTrue {
#[snafu(source(from(InnerError, Box::new)))]
cause: Box<InnerError>,
},
ExplicitFalse {
#[snafu(source(false))]
source: i32,
},
}
fn example() -> Result<(), Error> {
inner().context(NoArgumentSnafu)?;
inner().context(ExplicitTrueSnafu)?;
inner().context(FromImpliesTrueSnafu)?;
ExplicitFalseSnafu { source: 42 }.fail()?;
Ok(())
}
#[test]
fn implements_error() {
fn check<T: std::error::Error>() {}
check::<Error>();
example().unwrap_err();
}
}
mod transformation {
use super::*;
use std::io;
#[derive(Debug, Snafu)]
enum Error {
TransformationViaClosure {
#[snafu(source(from(InnerError, |e| io::Error::new(io::ErrorKind::InvalidData, e))))]
source: io::Error,
},
TransformationViaFunction {
#[snafu(source(from(InnerError, into_io)))]
source: io::Error,
},
TransformationToTraitObject {
#[snafu(source(from(InnerError, Box::new)))]
source: Box<dyn std::error::Error>,
},
}
fn into_io(e: InnerError) -> io::Error {
io::Error::new(io::ErrorKind::InvalidData, e)
}
fn example() -> Result<(), Error> {
inner().context(TransformationViaClosureSnafu)?;
inner().context(TransformationViaFunctionSnafu)?;
inner().context(TransformationToTraitObjectSnafu)?;
Ok(())
}
#[test]
fn implements_error() {
fn check<T: std::error::Error>() {}
check::<Error>();
example().unwrap();
}
#[derive(Debug, Snafu)]
#[snafu(source(from(Error, Box::new)))]
struct ApiError(Box<Error>);
fn api_example() -> Result<(), ApiError> {
example()?;
Ok(())
}
#[test]
fn api_implements_error() {
fn check<T: std::error::Error>() {}
check::<ApiError>();
api_example().unwrap();
}
}
|
