| 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(()))); |
| } |