extern crate failure;
#[macro_use]
extern crate failure_derive;
use failure::{Backtrace, Fail};
#[derive(Fail, Debug)]
#[fail(display = "Error code: {}", code)]
struct BacktraceError {
backtrace: Backtrace,
code: u32,
}
#[test]
fn backtrace_error() {
let err = BacktraceError {
backtrace: Backtrace::new(),
code: 7,
};
let s = format!("{}", err);
assert_eq!(&s[..], "Error code: 7");
assert!(err.backtrace().is_some());
}
#[derive(Fail, Debug)]
#[fail(display = "An error has occurred.")]
struct BacktraceTupleError(Backtrace);
#[test]
fn backtrace_tuple_error() {
let err = BacktraceTupleError(Backtrace::new());
let s = format!("{}", err);
assert_eq!(&s[..], "An error has occurred.");
assert!(err.backtrace().is_some());
}
#[derive(Fail, Debug)]
enum BacktraceEnumError {
#[fail(display = "Error code: {}", code)]
StructVariant { code: i32, backtrace: Backtrace },
#[fail(display = "Error: {}", _0)]
TupleVariant(&'static str, Backtrace),
#[fail(display = "An error has occurred.")]
UnitVariant,
}
#[test]
fn backtrace_enum_error() {
let err = BacktraceEnumError::StructVariant {
code: 2,
backtrace: Backtrace::new(),
};
let s = format!("{}", err);
assert_eq!(&s[..], "Error code: 2");
assert!(err.backtrace().is_some());
let err = BacktraceEnumError::TupleVariant("foobar", Backtrace::new());
let s = format!("{}", err);
assert_eq!(&s[..], "Error: foobar");
assert!(err.backtrace().is_some());
let err = BacktraceEnumError::UnitVariant;
let s = format!("{}", err);
assert_eq!(&s[..], "An error has occurred.");
assert!(err.backtrace().is_none());
}