mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-23 23:34:48 +00:00
419 lines
12 KiB
Rust
419 lines
12 KiB
Rust
use core::ops::DerefMut;
|
|
use core::option::*;
|
|
|
|
fn op1() -> Result<isize, &'static str> {
|
|
Ok(666)
|
|
}
|
|
fn op2() -> Result<isize, &'static str> {
|
|
Err("sadface")
|
|
}
|
|
|
|
#[test]
|
|
fn test_and() {
|
|
assert_eq!(op1().and(Ok(667)).unwrap(), 667);
|
|
assert_eq!(op1().and(Err::<i32, &'static str>("bad")).unwrap_err(), "bad");
|
|
|
|
assert_eq!(op2().and(Ok(667)).unwrap_err(), "sadface");
|
|
assert_eq!(op2().and(Err::<i32, &'static str>("bad")).unwrap_err(), "sadface");
|
|
}
|
|
|
|
#[test]
|
|
fn test_and_then() {
|
|
assert_eq!(op1().and_then(|i| Ok::<isize, &'static str>(i + 1)).unwrap(), 667);
|
|
assert_eq!(op1().and_then(|_| Err::<isize, &'static str>("bad")).unwrap_err(), "bad");
|
|
|
|
assert_eq!(op2().and_then(|i| Ok::<isize, &'static str>(i + 1)).unwrap_err(), "sadface");
|
|
assert_eq!(op2().and_then(|_| Err::<isize, &'static str>("bad")).unwrap_err(), "sadface");
|
|
}
|
|
|
|
#[test]
|
|
fn test_or() {
|
|
assert_eq!(op1().or(Ok::<_, &'static str>(667)).unwrap(), 666);
|
|
assert_eq!(op1().or(Err("bad")).unwrap(), 666);
|
|
|
|
assert_eq!(op2().or(Ok::<_, &'static str>(667)).unwrap(), 667);
|
|
assert_eq!(op2().or(Err("bad")).unwrap_err(), "bad");
|
|
}
|
|
|
|
#[test]
|
|
fn test_or_else() {
|
|
assert_eq!(op1().or_else(|_| Ok::<isize, &'static str>(667)).unwrap(), 666);
|
|
assert_eq!(op1().or_else(|e| Err::<isize, &'static str>(e)).unwrap(), 666);
|
|
|
|
assert_eq!(op2().or_else(|_| Ok::<isize, &'static str>(667)).unwrap(), 667);
|
|
assert_eq!(op2().or_else(|e| Err::<isize, &'static str>(e)).unwrap_err(), "sadface");
|
|
}
|
|
|
|
#[test]
|
|
fn test_impl_map() {
|
|
assert!(Ok::<isize, isize>(1).map(|x| x + 1) == Ok(2));
|
|
assert!(Err::<isize, isize>(1).map(|x| x + 1) == Err(1));
|
|
}
|
|
|
|
#[test]
|
|
fn test_impl_map_err() {
|
|
assert!(Ok::<isize, isize>(1).map_err(|x| x + 1) == Ok(1));
|
|
assert!(Err::<isize, isize>(1).map_err(|x| x + 1) == Err(2));
|
|
}
|
|
|
|
#[test]
|
|
fn test_collect() {
|
|
let v: Result<Vec<isize>, ()> = (0..0).map(|_| Ok::<isize, ()>(0)).collect();
|
|
assert!(v == Ok(vec![]));
|
|
|
|
let v: Result<Vec<isize>, ()> = (0..3).map(|x| Ok::<isize, ()>(x)).collect();
|
|
assert!(v == Ok(vec![0, 1, 2]));
|
|
|
|
let v: Result<Vec<isize>, isize> = (0..3).map(|x| if x > 1 { Err(x) } else { Ok(x) }).collect();
|
|
assert!(v == Err(2));
|
|
|
|
// test that it does not take more elements than it needs
|
|
let mut functions: [Box<dyn Fn() -> Result<(), isize>>; 3] =
|
|
[Box::new(|| Ok(())), Box::new(|| Err(1)), Box::new(|| panic!())];
|
|
|
|
let v: Result<Vec<()>, isize> = functions.iter_mut().map(|f| (*f)()).collect();
|
|
assert!(v == Err(1));
|
|
}
|
|
|
|
#[test]
|
|
fn test_fmt_default() {
|
|
let ok: Result<isize, &'static str> = Ok(100);
|
|
let err: Result<isize, &'static str> = Err("Err");
|
|
|
|
let s = format!("{ok:?}");
|
|
assert_eq!(s, "Ok(100)");
|
|
let s = format!("{err:?}");
|
|
assert_eq!(s, "Err(\"Err\")");
|
|
}
|
|
|
|
#[test]
|
|
fn test_unwrap_or() {
|
|
let ok: Result<isize, &'static str> = Ok(100);
|
|
let ok_err: Result<isize, &'static str> = Err("Err");
|
|
|
|
assert_eq!(ok.unwrap_or(50), 100);
|
|
assert_eq!(ok_err.unwrap_or(50), 50);
|
|
}
|
|
|
|
#[test]
|
|
fn test_unwrap_or_else() {
|
|
fn handler(msg: &'static str) -> isize {
|
|
if msg == "I got this." { 50 } else { panic!("BadBad") }
|
|
}
|
|
|
|
let ok: Result<isize, &'static str> = Ok(100);
|
|
let ok_err: Result<isize, &'static str> = Err("I got this.");
|
|
|
|
assert_eq!(ok.unwrap_or_else(handler), 100);
|
|
assert_eq!(ok_err.unwrap_or_else(handler), 50);
|
|
}
|
|
|
|
#[test]
|
|
#[should_panic]
|
|
pub fn test_unwrap_or_else_panic() {
|
|
fn handler(msg: &'static str) -> isize {
|
|
if msg == "I got this." { 50 } else { panic!("BadBad") }
|
|
}
|
|
|
|
let bad_err: Result<isize, &'static str> = Err("Unrecoverable mess.");
|
|
let _: isize = bad_err.unwrap_or_else(handler);
|
|
}
|
|
|
|
#[test]
|
|
fn test_unwrap_unchecked() {
|
|
let ok: Result<isize, &'static str> = Ok(100);
|
|
assert_eq!(unsafe { ok.unwrap_unchecked() }, 100);
|
|
}
|
|
|
|
#[test]
|
|
fn test_unwrap_err_unchecked() {
|
|
let ok_err: Result<isize, &'static str> = Err("Err");
|
|
assert_eq!(unsafe { ok_err.unwrap_err_unchecked() }, "Err");
|
|
}
|
|
|
|
#[test]
|
|
pub fn test_expect_ok() {
|
|
let ok: Result<isize, &'static str> = Ok(100);
|
|
assert_eq!(ok.expect("Unexpected error"), 100);
|
|
}
|
|
#[test]
|
|
#[should_panic(expected = "Got expected error: \"All good\"")]
|
|
pub fn test_expect_err() {
|
|
let err: Result<isize, &'static str> = Err("All good");
|
|
err.expect("Got expected error");
|
|
}
|
|
|
|
#[test]
|
|
pub fn test_expect_err_err() {
|
|
let ok: Result<&'static str, isize> = Err(100);
|
|
assert_eq!(ok.expect_err("Unexpected ok"), 100);
|
|
}
|
|
#[test]
|
|
#[should_panic(expected = "Got expected ok: \"All good\"")]
|
|
pub fn test_expect_err_ok() {
|
|
let err: Result<&'static str, isize> = Ok("All good");
|
|
err.expect_err("Got expected ok");
|
|
}
|
|
|
|
#[test]
|
|
pub fn test_iter() {
|
|
let ok: Result<isize, &'static str> = Ok(100);
|
|
let mut it = ok.iter();
|
|
assert_eq!(it.size_hint(), (1, Some(1)));
|
|
assert_eq!(it.next(), Some(&100));
|
|
assert_eq!(it.size_hint(), (0, Some(0)));
|
|
assert!(it.next().is_none());
|
|
assert_eq!((&ok).into_iter().next(), Some(&100));
|
|
|
|
let err: Result<isize, &'static str> = Err("error");
|
|
assert_eq!(err.iter().next(), None);
|
|
}
|
|
|
|
#[test]
|
|
pub fn test_iter_mut() {
|
|
let mut ok: Result<isize, &'static str> = Ok(100);
|
|
for loc in ok.iter_mut() {
|
|
*loc = 200;
|
|
}
|
|
assert_eq!(ok, Ok(200));
|
|
for loc in &mut ok {
|
|
*loc = 300;
|
|
}
|
|
assert_eq!(ok, Ok(300));
|
|
|
|
let mut err: Result<isize, &'static str> = Err("error");
|
|
for loc in err.iter_mut() {
|
|
*loc = 200;
|
|
}
|
|
assert_eq!(err, Err("error"));
|
|
}
|
|
|
|
#[test]
|
|
pub fn test_unwrap_or_default() {
|
|
assert_eq!(op1().unwrap_or_default(), 666);
|
|
assert_eq!(op2().unwrap_or_default(), 0);
|
|
}
|
|
|
|
#[test]
|
|
pub fn test_into_ok() {
|
|
fn infallible_op() -> Result<isize, !> {
|
|
Ok(666)
|
|
}
|
|
|
|
assert_eq!(infallible_op().into_ok(), 666);
|
|
|
|
enum MyNeverToken {}
|
|
impl From<MyNeverToken> for ! {
|
|
fn from(never: MyNeverToken) -> ! {
|
|
match never {}
|
|
}
|
|
}
|
|
|
|
fn infallible_op2() -> Result<isize, MyNeverToken> {
|
|
Ok(667)
|
|
}
|
|
|
|
assert_eq!(infallible_op2().into_ok(), 667);
|
|
}
|
|
|
|
#[test]
|
|
pub fn test_into_err() {
|
|
fn until_error_op() -> Result<!, isize> {
|
|
Err(666)
|
|
}
|
|
|
|
assert_eq!(until_error_op().into_err(), 666);
|
|
|
|
enum MyNeverToken {}
|
|
impl From<MyNeverToken> for ! {
|
|
fn from(never: MyNeverToken) -> ! {
|
|
match never {}
|
|
}
|
|
}
|
|
|
|
fn until_error_op2() -> Result<MyNeverToken, isize> {
|
|
Err(667)
|
|
}
|
|
|
|
assert_eq!(until_error_op2().into_err(), 667);
|
|
}
|
|
|
|
#[test]
|
|
fn test_try() {
|
|
fn try_result_ok() -> Result<u8, u32> {
|
|
let result: Result<u8, u8> = Ok(1);
|
|
let val = result?;
|
|
Ok(val)
|
|
}
|
|
assert_eq!(try_result_ok(), Ok(1));
|
|
|
|
fn try_result_err() -> Result<u8, u32> {
|
|
let result: Result<u8, u8> = Err(1);
|
|
let val = result?;
|
|
Ok(val)
|
|
}
|
|
assert_eq!(try_result_err(), Err(1));
|
|
}
|
|
|
|
#[test]
|
|
fn test_result_as_deref() {
|
|
// &Result<T: Deref, E>::Ok(T).as_deref() ->
|
|
// Result<&T::Deref::Target, &E>::Ok(&*T)
|
|
let ref_ok = &Result::Ok::<&i32, u8>(&42);
|
|
let expected_result = Result::Ok::<&i32, &u8>(&42);
|
|
assert_eq!(ref_ok.as_deref(), expected_result);
|
|
|
|
let ref_ok = &Result::Ok::<String, u32>(String::from("a result"));
|
|
let expected_result = Result::Ok::<&str, &u32>("a result");
|
|
assert_eq!(ref_ok.as_deref(), expected_result);
|
|
|
|
let ref_ok = &Result::Ok::<Vec<i32>, u32>(vec![1, 2, 3, 4, 5]);
|
|
let expected_result = Result::Ok::<&[i32], &u32>([1, 2, 3, 4, 5].as_slice());
|
|
assert_eq!(ref_ok.as_deref(), expected_result);
|
|
|
|
// &Result<T: Deref, E>::Err(T).as_deref() ->
|
|
// Result<&T::Deref::Target, &E>::Err(&*E)
|
|
let val = 41;
|
|
let ref_err = &Result::Err::<&u8, i32>(val);
|
|
let expected_result = Result::Err::<&u8, &i32>(&val);
|
|
assert_eq!(ref_err.as_deref(), expected_result);
|
|
|
|
let s = String::from("an error");
|
|
let ref_err = &Result::Err::<&u32, String>(s.clone());
|
|
let expected_result = Result::Err::<&u32, &String>(&s);
|
|
assert_eq!(ref_err.as_deref(), expected_result);
|
|
|
|
let v = vec![5, 4, 3, 2, 1];
|
|
let ref_err = &Result::Err::<&u32, Vec<i32>>(v.clone());
|
|
let expected_result = Result::Err::<&u32, &Vec<i32>>(&v);
|
|
assert_eq!(ref_err.as_deref(), expected_result);
|
|
}
|
|
|
|
#[test]
|
|
fn test_result_as_deref_mut() {
|
|
// &mut Result<T: DerefMut, E>::Ok(T).as_deref_mut() ->
|
|
// Result<&mut T::DerefMut::Target, &mut E>::Ok(&mut *T)
|
|
let mut val = 42;
|
|
let mut expected_val = 42;
|
|
let mut_ok = &mut Result::Ok::<&mut i32, u8>(&mut val);
|
|
let expected_result = Result::Ok::<&mut i32, &mut u8>(&mut expected_val);
|
|
assert_eq!(mut_ok.as_deref_mut(), expected_result);
|
|
|
|
let mut expected_string = String::from("a result");
|
|
let mut_ok = &mut Result::Ok::<String, u32>(expected_string.clone());
|
|
let expected_result = Result::Ok::<&mut str, &mut u32>(expected_string.deref_mut());
|
|
assert_eq!(mut_ok.as_deref_mut(), expected_result);
|
|
|
|
let mut expected_vec = vec![1, 2, 3, 4, 5];
|
|
let mut_ok = &mut Result::Ok::<Vec<i32>, u32>(expected_vec.clone());
|
|
let expected_result = Result::Ok::<&mut [i32], &mut u32>(expected_vec.as_mut_slice());
|
|
assert_eq!(mut_ok.as_deref_mut(), expected_result);
|
|
|
|
// &mut Result<T: DerefMut, E>::Err(T).as_deref_mut() ->
|
|
// Result<&mut T, &mut E>::Err(&mut *E)
|
|
let mut val = 41;
|
|
let mut_err = &mut Result::Err::<&mut u8, i32>(val);
|
|
let expected_result = Result::Err::<&mut u8, &mut i32>(&mut val);
|
|
assert_eq!(mut_err.as_deref_mut(), expected_result);
|
|
|
|
let mut expected_string = String::from("an error");
|
|
let mut_err = &mut Result::Err::<&mut u32, String>(expected_string.clone());
|
|
let expected_result = Result::Err::<&mut u32, &mut String>(&mut expected_string);
|
|
assert_eq!(mut_err.as_deref_mut(), expected_result);
|
|
|
|
let mut expected_vec = vec![5, 4, 3, 2, 1];
|
|
let mut_err = &mut Result::Err::<&mut u32, Vec<i32>>(expected_vec.clone());
|
|
let expected_result = Result::Err::<&mut u32, &mut Vec<i32>>(&mut expected_vec);
|
|
assert_eq!(mut_err.as_deref_mut(), expected_result);
|
|
}
|
|
|
|
#[test]
|
|
fn result_const() {
|
|
// test that the methods of `Result` are usable in a const context
|
|
|
|
const RESULT: Result<usize, bool> = Ok(32);
|
|
|
|
const REF: Result<&usize, &bool> = RESULT.as_ref();
|
|
assert_eq!(REF, Ok(&32));
|
|
|
|
const IS_OK: bool = RESULT.is_ok();
|
|
assert!(IS_OK);
|
|
|
|
const IS_ERR: bool = RESULT.is_err();
|
|
assert!(!IS_ERR)
|
|
}
|
|
|
|
#[test]
|
|
const fn result_const_mut() {
|
|
let mut result: Result<usize, bool> = Ok(32);
|
|
|
|
{
|
|
let as_mut = result.as_mut();
|
|
match as_mut {
|
|
Ok(v) => *v = 42,
|
|
Err(_) => unreachable!(),
|
|
}
|
|
}
|
|
|
|
let mut result_err: Result<usize, bool> = Err(false);
|
|
|
|
{
|
|
let as_mut = result_err.as_mut();
|
|
match as_mut {
|
|
Ok(_) => unreachable!(),
|
|
Err(v) => *v = true,
|
|
}
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn result_opt_conversions() {
|
|
#[derive(Copy, Clone, Debug, PartialEq)]
|
|
struct BadNumErr;
|
|
|
|
fn try_num(x: i32) -> Result<i32, BadNumErr> {
|
|
if x <= 5 { Ok(x + 1) } else { Err(BadNumErr) }
|
|
}
|
|
|
|
type ResOpt = Result<Option<i32>, BadNumErr>;
|
|
type OptRes = Option<Result<i32, BadNumErr>>;
|
|
|
|
let mut x: ResOpt = Ok(Some(5));
|
|
let mut y: OptRes = Some(Ok(5));
|
|
assert_eq!(x, y.transpose());
|
|
assert_eq!(x.transpose(), y);
|
|
|
|
x = Ok(None);
|
|
y = None;
|
|
assert_eq!(x, y.transpose());
|
|
assert_eq!(x.transpose(), y);
|
|
|
|
x = Err(BadNumErr);
|
|
y = Some(Err(BadNumErr));
|
|
assert_eq!(x, y.transpose());
|
|
assert_eq!(x.transpose(), y);
|
|
|
|
let res: Result<Vec<i32>, BadNumErr> = (0..10)
|
|
.map(|x| {
|
|
let y = try_num(x)?;
|
|
Ok(if y % 2 == 0 { Some(y - 1) } else { None })
|
|
})
|
|
.filter_map(Result::transpose)
|
|
.collect();
|
|
|
|
assert_eq!(res, Err(BadNumErr))
|
|
}
|
|
|
|
#[test]
|
|
fn result_try_trait_v2_branch() {
|
|
use core::num::NonZeroU32;
|
|
use core::ops::{ControlFlow::*, Try};
|
|
assert_eq!(Ok::<i32, i32>(4).branch(), Continue(4));
|
|
assert_eq!(Err::<i32, i32>(4).branch(), Break(Err(4)));
|
|
let one = NonZeroU32::new(1).unwrap();
|
|
assert_eq!(Ok::<(), NonZeroU32>(()).branch(), Continue(()));
|
|
assert_eq!(Err::<(), NonZeroU32>(one).branch(), Break(Err(one)));
|
|
assert_eq!(Ok::<NonZeroU32, ()>(one).branch(), Continue(one));
|
|
assert_eq!(Err::<NonZeroU32, ()>(()).branch(), Break(Err(())));
|
|
}
|