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|
use std::fmt::{self, Display};
use thiserror::Error;
fn assert<T: Display>(expected: &str, value: T) {
assert_eq!(expected, value.to_string());
}
#[test]
fn test_braced() {
#[derive(Error, Debug)]
#[error("braced error: {msg}")]
struct Error {
msg: String,
}
let msg = "T".to_owned();
assert("braced error: T", Error { msg });
}
#[test]
fn test_braced_unused() {
#[derive(Error, Debug)]
#[error("braced error")]
struct Error {
extra: usize,
}
assert("braced error", Error { extra: 0 });
}
#[test]
fn test_tuple() {
#[derive(Error, Debug)]
#[error("tuple error: {0}")]
struct Error(usize);
assert("tuple error: 0", Error(0));
}
#[test]
fn test_unit() {
#[derive(Error, Debug)]
#[error("unit error")]
struct Error;
assert("unit error", Error);
}
#[test]
fn test_enum() {
#[derive(Error, Debug)]
enum Error {
#[error("braced error: {id}")]
Braced { id: usize },
#[error("tuple error: {0}")]
Tuple(usize),
#[error("unit error")]
Unit,
}
assert("braced error: 0", Error::Braced { id: 0 });
assert("tuple error: 0", Error::Tuple(0));
assert("unit error", Error::Unit);
}
#[test]
fn test_constants() {
#[derive(Error, Debug)]
#[error("{MSG}: {id:?} (code {CODE:?})")]
struct Error {
id: &'static str,
}
const MSG: &str = "failed to do";
const CODE: usize = 9;
assert("failed to do: \"\" (code 9)", Error { id: "" });
}
#[test]
fn test_inherit() {
#[derive(Error, Debug)]
#[error("{0}")]
enum Error {
Some(&'static str),
#[error("other error")]
Other(&'static str),
}
assert("some error", Error::Some("some error"));
assert("other error", Error::Other("..."));
}
#[test]
fn test_brace_escape() {
#[derive(Error, Debug)]
#[error("fn main() {{}}")]
struct Error;
assert("fn main() {}", Error);
}
#[test]
fn test_expr() {
#[derive(Error, Debug)]
#[error("1 + 1 = {}", 1 + 1)]
struct Error;
assert("1 + 1 = 2", Error);
}
#[test]
fn test_nested() {
#[derive(Error, Debug)]
#[error("!bool = {}", not(.0))]
struct Error(bool);
#[allow(clippy::trivially_copy_pass_by_ref)]
fn not(bool: &bool) -> bool {
!*bool
}
assert("!bool = false", Error(true));
}
#[test]
fn test_match() {
#[derive(Error, Debug)]
#[error("{}: {0}", match .1 {
Some(n) => format!("error occurred with {}", n),
None => "there was an empty error".to_owned(),
})]
struct Error(String, Option<usize>);
assert(
"error occurred with 1: ...",
Error("...".to_owned(), Some(1)),
);
assert(
"there was an empty error: ...",
Error("...".to_owned(), None),
);
}
#[test]
fn test_nested_display() {
// Same behavior as the one in `test_match`, but without String allocations.
#[derive(Error, Debug)]
#[error("{}", {
struct Msg<'a>(&'a String, &'a Option<usize>);
impl<'a> Display for Msg<'a> {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
match self.1 {
Some(n) => write!(formatter, "error occurred with {}", n),
None => write!(formatter, "there was an empty error"),
}?;
write!(formatter, ": {}", self.0)
}
}
Msg(.0, .1)
})]
struct Error(String, Option<usize>);
assert(
"error occurred with 1: ...",
Error("...".to_owned(), Some(1)),
);
assert(
"there was an empty error: ...",
Error("...".to_owned(), None),
);
}
#[test]
fn test_void() {
#[allow(clippy::empty_enum)]
#[derive(Error, Debug)]
#[error("...")]
pub enum Error {}
let _: Error;
}
#[test]
fn test_mixed() {
#[derive(Error, Debug)]
#[error("a={a} :: b={} :: c={c} :: d={d}", 1, c = 2, d = 3)]
struct Error {
a: usize,
d: usize,
}
assert("a=0 :: b=1 :: c=2 :: d=3", Error { a: 0, d: 0 });
}
#[test]
fn test_ints() {
#[derive(Error, Debug)]
enum Error {
#[error("error {0}")]
Tuple(usize, usize),
#[error("error {0}", '?')]
Struct { v: usize },
}
assert("error 9", Error::Tuple(9, 0));
assert("error ?", Error::Struct { v: 0 });
}
#[test]
fn test_trailing_comma() {
#[derive(Error, Debug)]
#[error(
"error {0}",
)]
#[rustfmt::skip]
struct Error(char);
assert("error ?", Error('?'));
}
#[test]
fn test_field() {
#[derive(Debug)]
struct Inner {
data: usize,
}
#[derive(Error, Debug)]
#[error("{}", .0.data)]
struct Error(Inner);
assert("0", Error(Inner { data: 0 }));
}
#[test]
fn test_macro_rules() {
// Regression test for https://github.com/dtolnay/thiserror/issues/86
macro_rules! decl_error {
($variant:ident($value:ident)) => {
#[derive(Debug, Error)]
pub enum Error0 {
#[error("{0:?}")]
$variant($value),
}
#[derive(Debug, Error)]
#[error("{0:?}")]
pub enum Error1 {
$variant($value),
}
};
}
decl_error!(Repro(u8));
assert("0", Error0::Repro(0));
assert("0", Error1::Repro(0));
}
#[test]
fn test_raw() {
#[derive(Error, Debug)]
#[error("braced raw error: {r#fn}")]
struct Error {
r#fn: &'static str,
}
assert("braced raw error: T", Error { r#fn: "T" });
}
#[test]
fn test_raw_enum() {
#[derive(Error, Debug)]
enum Error {
#[error("braced raw error: {r#fn}")]
Braced { r#fn: &'static str },
}
assert("braced raw error: T", Error::Braced { r#fn: "T" });
}
#[test]
fn test_raw_conflict() {
#[derive(Error, Debug)]
enum Error {
#[error("braced raw error: {r#func}, {func}", func = "U")]
Braced { r#func: &'static str },
}
assert("braced raw error: T, U", Error::Braced { r#func: "T" });
}
#[test]
fn test_keyword() {
#[derive(Error, Debug)]
#[error("error: {type}", type = 1)]
struct Error;
assert("error: 1", Error);
}
|
