use cosmwasm_std::{
CheckedFromRatioError, Decimal, Decimal256, DecimalRangeExceeded, DivideByZeroError, Fraction,
Int128, Int256, OverflowError, OverflowOperation, RoundUpOverflowError, SignedDecimal,
SignedDecimal256, Uint128, Uint256,
};
use std::fmt::Write;
use std::str::FromStr;
const DECIMAL_FRACTIONAL: Uint128 = Uint128::new(1_000_000_000_000_000_000);
fn dec(input: &str) -> Decimal {
Decimal::from_str(input).unwrap()
}
#[test]
fn decimal_new() {
let expected = Uint128::from(300u128);
assert_eq!("0.0000000000000003", Decimal::new(expected).to_string());
}
#[test]
#[allow(deprecated)]
fn decimal_raw() {
let value = 300u128;
assert_eq!(Decimal::raw(value), Decimal::new(Uint128::from(300u128)));
}
#[test]
fn decimal_one() {
let value = Decimal::one();
assert_eq!(value, Decimal::new(DECIMAL_FRACTIONAL));
}
#[test]
fn decimal_zero() {
let value = Decimal::zero();
assert!(value.is_zero());
}
#[test]
fn decimal_percent() {
let value = Decimal::percent(50);
assert_eq!(value, Decimal::new(DECIMAL_FRACTIONAL / Uint128::from(2u8)));
}
#[test]
fn decimal_permille() {
let value = Decimal::permille(125);
assert_eq!(value, Decimal::new(DECIMAL_FRACTIONAL / Uint128::from(8u8)));
}
#[test]
fn decimal_bps() {
let value = Decimal::bps(125);
assert_eq!(
value,
Decimal::new(DECIMAL_FRACTIONAL / Uint128::from(80u8))
);
}
#[test]
fn decimal_from_decimal256_works() {
let too_big = Decimal256::new(Uint256::from(Uint128::MAX) + Uint256::one());
assert_eq!(Decimal::try_from(too_big), Err(DecimalRangeExceeded));
let just_right = Decimal256::new(Uint256::from(Uint128::MAX));
assert_eq!(Decimal::try_from(just_right), Ok(Decimal::MAX));
assert_eq!(Decimal::try_from(Decimal256::zero()), Ok(Decimal::zero()));
assert_eq!(Decimal::try_from(Decimal256::one()), Ok(Decimal::one()));
assert_eq!(
Decimal::try_from(Decimal256::percent(50)),
Ok(Decimal::percent(50))
);
}
#[test]
fn decimal_from_signed_decimal256_works() {
let too_big = SignedDecimal256::new(Int256::from(Int128::MAX) * Int256::from(Int128::MAX));
assert_eq!(Decimal::try_from(too_big), Err(DecimalRangeExceeded));
let just_right =
SignedDecimal256::new(Int256::new(i128::MAX) + Int256::new(i128::MAX) + Int256::one());
assert_eq!(Decimal::try_from(just_right), Ok(Decimal::MAX));
assert_eq!(
Decimal::try_from(SignedDecimal256::zero()),
Ok(Decimal::zero())
);
assert_eq!(
Decimal::try_from(SignedDecimal256::one()),
Ok(Decimal::one())
);
assert_eq!(
Decimal::try_from(SignedDecimal256::percent(50)),
Ok(Decimal::percent(50))
);
}
#[test]
fn decimal_try_from_integer() {
let int = Uint128::new(0xDEADBEEF);
let decimal = Decimal::try_from(int).unwrap();
assert_eq!(int.to_string(), decimal.to_string());
}
#[test]
fn decimal_try_from_signed_works() {
assert_eq!(
Decimal::try_from(SignedDecimal::MAX).unwrap(),
Decimal::new(Uint128::new(SignedDecimal::MAX.atomics().i128() as u128))
);
assert_eq!(
Decimal::try_from(SignedDecimal::zero()).unwrap(),
Decimal::zero()
);
assert_eq!(
Decimal::try_from(SignedDecimal::one()).unwrap(),
Decimal::one()
);
assert_eq!(
Decimal::try_from(SignedDecimal::percent(50)).unwrap(),
Decimal::percent(50)
);
assert_eq!(
Decimal::try_from(SignedDecimal::negative_one()),
Err(DecimalRangeExceeded)
);
assert_eq!(
Decimal::try_from(SignedDecimal::MIN),
Err(DecimalRangeExceeded)
);
}
#[test]
fn decimal_from_atomics_works() {
let one = Decimal::one();
let two = one + one;
assert_eq!(Decimal::from_atomics(1u128, 0).unwrap(), one);
assert_eq!(Decimal::from_atomics(10u128, 1).unwrap(), one);
assert_eq!(Decimal::from_atomics(100u128, 2).unwrap(), one);
assert_eq!(Decimal::from_atomics(1000u128, 3).unwrap(), one);
assert_eq!(
Decimal::from_atomics(1000000000000000000u128, 18).unwrap(),
one
);
assert_eq!(
Decimal::from_atomics(10000000000000000000u128, 19).unwrap(),
one
);
assert_eq!(
Decimal::from_atomics(100000000000000000000u128, 20).unwrap(),
one
);
assert_eq!(Decimal::from_atomics(2u128, 0).unwrap(), two);
assert_eq!(Decimal::from_atomics(20u128, 1).unwrap(), two);
assert_eq!(Decimal::from_atomics(200u128, 2).unwrap(), two);
assert_eq!(Decimal::from_atomics(2000u128, 3).unwrap(), two);
assert_eq!(
Decimal::from_atomics(2000000000000000000u128, 18).unwrap(),
two
);
assert_eq!(
Decimal::from_atomics(20000000000000000000u128, 19).unwrap(),
two
);
assert_eq!(
Decimal::from_atomics(200000000000000000000u128, 20).unwrap(),
two
);
assert_eq!(
Decimal::from_atomics(4321u128, 20).unwrap(),
Decimal::from_str("0.000000000000000043").unwrap()
);
assert_eq!(
Decimal::from_atomics(6789u128, 20).unwrap(),
Decimal::from_str("0.000000000000000067").unwrap()
);
assert_eq!(
Decimal::from_atomics(u128::MAX, 38).unwrap(),
Decimal::from_str("3.402823669209384634").unwrap()
);
assert_eq!(
Decimal::from_atomics(u128::MAX, 39).unwrap(),
Decimal::from_str("0.340282366920938463").unwrap()
);
assert_eq!(
Decimal::from_atomics(u128::MAX, 45).unwrap(),
Decimal::from_str("0.000000340282366920").unwrap()
);
assert_eq!(
Decimal::from_atomics(u128::MAX, 51).unwrap(),
Decimal::from_str("0.000000000000340282").unwrap()
);
assert_eq!(
Decimal::from_atomics(u128::MAX, 56).unwrap(),
Decimal::from_str("0.000000000000000003").unwrap()
);
assert_eq!(
Decimal::from_atomics(u128::MAX, 57).unwrap(),
Decimal::from_str("0.000000000000000000").unwrap()
);
assert_eq!(
Decimal::from_atomics(u128::MAX, u32::MAX).unwrap(),
Decimal::from_str("0.000000000000000000").unwrap()
);
assert_eq!(
Decimal::from_atomics(0u128, u32::MAX).unwrap(),
Decimal::zero()
);
let max = Decimal::MAX;
assert_eq!(
Decimal::from_atomics(max.atomics(), max.decimal_places()).unwrap(),
max
);
let result = Decimal::from_atomics(u128::MAX, 17);
assert_eq!(result.unwrap_err(), DecimalRangeExceeded);
}
#[test]
fn decimal_from_ratio_works() {
assert_eq!(Decimal::from_ratio(1u128, 1u128), Decimal::one());
assert_eq!(Decimal::from_ratio(53u128, 53u128), Decimal::one());
assert_eq!(Decimal::from_ratio(125u128, 125u128), Decimal::one());
assert_eq!(Decimal::from_ratio(3u128, 2u128), Decimal::percent(150));
assert_eq!(Decimal::from_ratio(150u128, 100u128), Decimal::percent(150));
assert_eq!(Decimal::from_ratio(333u128, 222u128), Decimal::percent(150));
assert_eq!(Decimal::from_ratio(1u64, 8u64), Decimal::permille(125));
assert_eq!(Decimal::from_ratio(125u64, 1000u64), Decimal::permille(125));
assert_eq!(
Decimal::from_ratio(1u64, 3u64),
Decimal::new(Uint128::from(333_333_333_333_333_333u128))
);
assert_eq!(
Decimal::from_ratio(2u64, 3u64),
Decimal::new(Uint128::from(666_666_666_666_666_666u128))
);
assert_eq!(Decimal::from_ratio(0u128, u128::MAX), Decimal::zero());
assert_eq!(Decimal::from_ratio(u128::MAX, u128::MAX), Decimal::one());
assert_eq!(
Decimal::from_ratio(340282366920938463463u128, 1u128),
Decimal::from_str("340282366920938463463").unwrap()
);
}
#[test]
#[should_panic(expected = "Denominator must not be zero")]
fn decimal_from_ratio_panics_for_zero_denominator() {
Decimal::from_ratio(1u128, 0u128);
}
#[test]
#[should_panic(expected = "Multiplication overflow")]
fn decimal_from_ratio_panics_for_mul_overflow() {
Decimal::from_ratio(u128::MAX, 1u128);
}
#[test]
fn decimal_checked_from_ratio_does_not_panic() {
assert_eq!(
Decimal::checked_from_ratio(1u128, 0u128),
Err(CheckedFromRatioError::DivideByZero)
);
assert_eq!(
Decimal::checked_from_ratio(u128::MAX, 1u128),
Err(CheckedFromRatioError::Overflow)
);
}
#[test]
fn decimal_implements_fraction() {
let fraction = Decimal::from_str("1234.567").unwrap();
assert_eq!(
fraction.numerator(),
Uint128::from(1_234_567_000_000_000_000_000u128)
);
assert_eq!(
fraction.denominator(),
Uint128::from(1_000_000_000_000_000_000u128)
);
}
#[test]
fn decimal_from_str_works() {
assert_eq!(Decimal::from_str("0").unwrap(), Decimal::percent(0));
assert_eq!(Decimal::from_str("1").unwrap(), Decimal::percent(100));
assert_eq!(Decimal::from_str("5").unwrap(), Decimal::percent(500));
assert_eq!(Decimal::from_str("42").unwrap(), Decimal::percent(4200));
assert_eq!(Decimal::from_str("000").unwrap(), Decimal::percent(0));
assert_eq!(Decimal::from_str("001").unwrap(), Decimal::percent(100));
assert_eq!(Decimal::from_str("005").unwrap(), Decimal::percent(500));
assert_eq!(Decimal::from_str("0042").unwrap(), Decimal::percent(4200));
assert_eq!(Decimal::from_str("1.0").unwrap(), Decimal::percent(100));
assert_eq!(Decimal::from_str("1.5").unwrap(), Decimal::percent(150));
assert_eq!(Decimal::from_str("0.5").unwrap(), Decimal::percent(50));
assert_eq!(Decimal::from_str("0.123").unwrap(), Decimal::permille(123));
assert_eq!(Decimal::from_str("40.00").unwrap(), Decimal::percent(4000));
assert_eq!(Decimal::from_str("04.00").unwrap(), Decimal::percent(400));
assert_eq!(Decimal::from_str("00.40").unwrap(), Decimal::percent(40));
assert_eq!(Decimal::from_str("00.04").unwrap(), Decimal::percent(4));
assert_eq!(
Decimal::from_str("7.123456789012345678").unwrap(),
Decimal::new(Uint128::from(7123456789012345678u128))
);
assert_eq!(
Decimal::from_str("7.999999999999999999").unwrap(),
Decimal::new(Uint128::from(7999999999999999999u128))
);
assert_eq!(
Decimal::from_str("340282366920938463463.374607431768211455").unwrap(),
Decimal::MAX
);
}
#[test]
fn decimal_from_str_errors_for_broken_whole_part() {
assert!(Decimal::from_str("").is_err());
assert!(Decimal::from_str(" ").is_err());
assert!(Decimal::from_str("-1").is_err());
}
#[test]
fn decimal_from_str_errors_for_broken_fractional_part() {
assert!(Decimal::from_str("1.").is_err());
assert!(Decimal::from_str("1. ").is_err());
assert!(Decimal::from_str("1.e").is_err());
assert!(Decimal::from_str("1.2e3").is_err());
}
#[test]
fn decimal_from_str_errors_for_more_than_18_fractional_digits() {
assert!(Decimal::from_str("7.1234567890123456789")
.unwrap_err()
.to_string()
.ends_with("Cannot parse more than 18 fractional digits"));
assert!(Decimal::from_str("7.1230000000000000000")
.unwrap_err()
.to_string()
.ends_with("Cannot parse more than 18 fractional digits"));
}
#[test]
fn decimal_from_str_errors_for_invalid_number_of_dots() {
assert!(Decimal::from_str("1.2.3").is_err());
assert!(Decimal::from_str("1.2.3.4").is_err());
}
#[test]
fn decimal_from_str_errors_for_more_than_max_value() {
assert!(Decimal::from_str("340282366920938463464").is_err());
assert!(Decimal::from_str("340282366920938463464.0").is_err());
assert!(Decimal::from_str("340282366920938463463.374607431768211456").is_err());
}
#[test]
fn decimal_atomics_works() {
let zero = Decimal::zero();
let one = Decimal::one();
let half = Decimal::percent(50);
let two = Decimal::percent(200);
let max = Decimal::MAX;
assert_eq!(zero.atomics(), Uint128::new(0));
assert_eq!(one.atomics(), Uint128::new(1000000000000000000));
assert_eq!(half.atomics(), Uint128::new(500000000000000000));
assert_eq!(two.atomics(), Uint128::new(2000000000000000000));
assert_eq!(max.atomics(), Uint128::MAX);
}
#[test]
fn decimal_decimal_places_works() {
let zero = Decimal::zero();
let one = Decimal::one();
let half = Decimal::percent(50);
let two = Decimal::percent(200);
let max = Decimal::MAX;
assert_eq!(zero.decimal_places(), 18);
assert_eq!(one.decimal_places(), 18);
assert_eq!(half.decimal_places(), 18);
assert_eq!(two.decimal_places(), 18);
assert_eq!(max.decimal_places(), 18);
}
#[test]
fn decimal_is_zero_works() {
assert!(Decimal::zero().is_zero());
assert!(Decimal::percent(0).is_zero());
assert!(Decimal::permille(0).is_zero());
assert!(!Decimal::one().is_zero());
assert!(!Decimal::percent(123).is_zero());
assert!(!Decimal::permille(1234).is_zero());
}
#[test]
fn decimal_inv_works() {
assert_eq!(Decimal::zero().inv(), None);
assert_eq!(Decimal::one().inv(), Some(Decimal::one()));
assert_eq!(
Decimal::from_str("2").unwrap().inv(),
Some(Decimal::from_str("0.5").unwrap())
);
assert_eq!(
Decimal::from_str("20").unwrap().inv(),
Some(Decimal::from_str("0.05").unwrap())
);
assert_eq!(
Decimal::from_str("200").unwrap().inv(),
Some(Decimal::from_str("0.005").unwrap())
);
assert_eq!(
Decimal::from_str("2000").unwrap().inv(),
Some(Decimal::from_str("0.0005").unwrap())
);
assert_eq!(
Decimal::from_str("3").unwrap().inv(),
Some(Decimal::from_str("0.333333333333333333").unwrap())
);
assert_eq!(
Decimal::from_str("6").unwrap().inv(),
Some(Decimal::from_str("0.166666666666666666").unwrap())
);
assert_eq!(
Decimal::from_str("0.5").unwrap().inv(),
Some(Decimal::from_str("2").unwrap())
);
assert_eq!(
Decimal::from_str("0.05").unwrap().inv(),
Some(Decimal::from_str("20").unwrap())
);
assert_eq!(
Decimal::from_str("0.005").unwrap().inv(),
Some(Decimal::from_str("200").unwrap())
);
assert_eq!(
Decimal::from_str("0.0005").unwrap().inv(),
Some(Decimal::from_str("2000").unwrap())
);
}
#[test]
#[allow(clippy::op_ref)]
fn decimal_add_works() {
let value = Decimal::one() + Decimal::percent(50); assert_eq!(
value,
Decimal::new(DECIMAL_FRACTIONAL * Uint128::from(3u8) / Uint128::from(2u8))
);
assert_eq!(
Decimal::percent(5) + Decimal::percent(4),
Decimal::percent(9)
);
assert_eq!(Decimal::percent(5) + Decimal::zero(), Decimal::percent(5));
assert_eq!(Decimal::zero() + Decimal::zero(), Decimal::zero());
let a = Decimal::percent(15);
let b = Decimal::percent(25);
let expected = Decimal::percent(40);
assert_eq!(a + b, expected);
assert_eq!(&a + b, expected);
assert_eq!(a + &b, expected);
assert_eq!(&a + &b, expected);
}
#[test]
#[should_panic(expected = "attempt to add with overflow")]
fn decimal_add_overflow_panics() {
let _value = Decimal::MAX + Decimal::percent(50);
}
#[test]
fn decimal_add_assign_works() {
let mut a = Decimal::percent(30);
a += Decimal::percent(20);
assert_eq!(a, Decimal::percent(50));
let mut a = Decimal::percent(15);
let b = Decimal::percent(3);
let expected = Decimal::percent(18);
a += &b;
assert_eq!(a, expected);
}
#[test]
#[allow(clippy::op_ref)]
fn decimal_sub_works() {
let value = Decimal::one() - Decimal::percent(50); assert_eq!(value, Decimal::new(DECIMAL_FRACTIONAL / Uint128::from(2u8)));
assert_eq!(
Decimal::percent(9) - Decimal::percent(4),
Decimal::percent(5)
);
assert_eq!(Decimal::percent(16) - Decimal::zero(), Decimal::percent(16));
assert_eq!(Decimal::percent(16) - Decimal::percent(16), Decimal::zero());
assert_eq!(Decimal::zero() - Decimal::zero(), Decimal::zero());
let a = Decimal::percent(13);
let b = Decimal::percent(6);
let expected = Decimal::percent(7);
assert_eq!(a - b, expected);
assert_eq!(&a - b, expected);
assert_eq!(a - &b, expected);
assert_eq!(&a - &b, expected);
}
#[test]
#[should_panic(expected = "attempt to subtract with overflow")]
fn decimal_sub_overflow_panics() {
let _value = Decimal::zero() - Decimal::percent(50);
}
#[test]
fn decimal_sub_assign_works() {
let mut a = Decimal::percent(20);
a -= Decimal::percent(2);
assert_eq!(a, Decimal::percent(18));
let mut a = Decimal::percent(33);
let b = Decimal::percent(13);
let expected = Decimal::percent(20);
a -= &b;
assert_eq!(a, expected);
}
#[test]
#[allow(clippy::op_ref)]
fn decimal_implements_mul() {
let one = Decimal::one();
let two = one + one;
let half = Decimal::percent(50);
assert_eq!(one * Decimal::percent(0), Decimal::percent(0));
assert_eq!(one * Decimal::percent(1), Decimal::percent(1));
assert_eq!(one * Decimal::percent(10), Decimal::percent(10));
assert_eq!(one * Decimal::percent(100), Decimal::percent(100));
assert_eq!(one * Decimal::percent(1000), Decimal::percent(1000));
assert_eq!(one * Decimal::MAX, Decimal::MAX);
assert_eq!(Decimal::percent(0) * one, Decimal::percent(0));
assert_eq!(Decimal::percent(1) * one, Decimal::percent(1));
assert_eq!(Decimal::percent(10) * one, Decimal::percent(10));
assert_eq!(Decimal::percent(100) * one, Decimal::percent(100));
assert_eq!(Decimal::percent(1000) * one, Decimal::percent(1000));
assert_eq!(Decimal::MAX * one, Decimal::MAX);
assert_eq!(two * Decimal::percent(0), Decimal::percent(0));
assert_eq!(two * Decimal::percent(1), Decimal::percent(2));
assert_eq!(two * Decimal::percent(10), Decimal::percent(20));
assert_eq!(two * Decimal::percent(100), Decimal::percent(200));
assert_eq!(two * Decimal::percent(1000), Decimal::percent(2000));
assert_eq!(Decimal::percent(0) * two, Decimal::percent(0));
assert_eq!(Decimal::percent(1) * two, Decimal::percent(2));
assert_eq!(Decimal::percent(10) * two, Decimal::percent(20));
assert_eq!(Decimal::percent(100) * two, Decimal::percent(200));
assert_eq!(Decimal::percent(1000) * two, Decimal::percent(2000));
assert_eq!(half * Decimal::percent(0), Decimal::percent(0));
assert_eq!(half * Decimal::percent(1), Decimal::permille(5));
assert_eq!(half * Decimal::percent(10), Decimal::percent(5));
assert_eq!(half * Decimal::percent(100), Decimal::percent(50));
assert_eq!(half * Decimal::percent(1000), Decimal::percent(500));
assert_eq!(Decimal::percent(0) * half, Decimal::percent(0));
assert_eq!(Decimal::percent(1) * half, Decimal::permille(5));
assert_eq!(Decimal::percent(10) * half, Decimal::percent(5));
assert_eq!(Decimal::percent(100) * half, Decimal::percent(50));
assert_eq!(Decimal::percent(1000) * half, Decimal::percent(500));
let a = dec("123.127726548762582");
assert_eq!(a * dec("1"), dec("123.127726548762582"));
assert_eq!(a * dec("10"), dec("1231.27726548762582"));
assert_eq!(a * dec("100"), dec("12312.7726548762582"));
assert_eq!(a * dec("1000"), dec("123127.726548762582"));
assert_eq!(a * dec("1000000"), dec("123127726.548762582"));
assert_eq!(a * dec("1000000000"), dec("123127726548.762582"));
assert_eq!(a * dec("1000000000000"), dec("123127726548762.582"));
assert_eq!(a * dec("1000000000000000"), dec("123127726548762582"));
assert_eq!(a * dec("1000000000000000000"), dec("123127726548762582000"));
assert_eq!(dec("1") * a, dec("123.127726548762582"));
assert_eq!(dec("10") * a, dec("1231.27726548762582"));
assert_eq!(dec("100") * a, dec("12312.7726548762582"));
assert_eq!(dec("1000") * a, dec("123127.726548762582"));
assert_eq!(dec("1000000") * a, dec("123127726.548762582"));
assert_eq!(dec("1000000000") * a, dec("123127726548.762582"));
assert_eq!(dec("1000000000000") * a, dec("123127726548762.582"));
assert_eq!(dec("1000000000000000") * a, dec("123127726548762582"));
assert_eq!(dec("1000000000000000000") * a, dec("123127726548762582000"));
let max = Decimal::MAX;
assert_eq!(
max * dec("1.0"),
dec("340282366920938463463.374607431768211455")
);
assert_eq!(
max * dec("0.1"),
dec("34028236692093846346.337460743176821145")
);
assert_eq!(
max * dec("0.01"),
dec("3402823669209384634.633746074317682114")
);
assert_eq!(
max * dec("0.001"),
dec("340282366920938463.463374607431768211")
);
assert_eq!(
max * dec("0.000001"),
dec("340282366920938.463463374607431768")
);
assert_eq!(
max * dec("0.000000001"),
dec("340282366920.938463463374607431")
);
assert_eq!(
max * dec("0.000000000001"),
dec("340282366.920938463463374607")
);
assert_eq!(
max * dec("0.000000000000001"),
dec("340282.366920938463463374")
);
assert_eq!(
max * dec("0.000000000000000001"),
dec("340.282366920938463463")
);
let a = Decimal::percent(20);
let b = Decimal::percent(30);
let expected = Decimal::percent(6);
assert_eq!(a * b, expected);
assert_eq!(&a * b, expected);
assert_eq!(a * &b, expected);
assert_eq!(&a * &b, expected);
}
#[test]
fn decimal_mul_assign_works() {
let mut a = Decimal::percent(15);
a *= Decimal::percent(60);
assert_eq!(a, Decimal::percent(9));
let mut a = Decimal::percent(50);
let b = Decimal::percent(20);
a *= &b;
assert_eq!(a, Decimal::percent(10));
}
#[test]
#[should_panic(expected = "attempt to multiply with overflow")]
fn decimal_mul_overflow_panics() {
let _value = Decimal::MAX * Decimal::percent(101);
}
#[test]
fn decimal_checked_mul() {
let test_data = [
(Decimal::zero(), Decimal::zero()),
(Decimal::zero(), Decimal::one()),
(Decimal::one(), Decimal::zero()),
(Decimal::percent(10), Decimal::zero()),
(Decimal::percent(10), Decimal::percent(5)),
(Decimal::MAX, Decimal::one()),
(Decimal::MAX / Uint128::new(2), Decimal::percent(200)),
(Decimal::permille(6), Decimal::permille(13)),
];
for (x, y) in test_data.into_iter() {
assert_eq!(x * y, x.checked_mul(y).unwrap());
}
}
#[test]
fn decimal_checked_mul_overflow() {
assert_eq!(
Decimal::MAX.checked_mul(Decimal::percent(200)),
Err(OverflowError::new(OverflowOperation::Mul))
);
}
#[test]
#[allow(clippy::op_ref)]
fn decimal_implements_div() {
let one = Decimal::one();
let two = one + one;
let half = Decimal::percent(50);
assert_eq!(one / Decimal::percent(1), Decimal::percent(10_000));
assert_eq!(one / Decimal::percent(10), Decimal::percent(1_000));
assert_eq!(one / Decimal::percent(100), Decimal::percent(100));
assert_eq!(one / Decimal::percent(1000), Decimal::percent(10));
assert_eq!(Decimal::percent(0) / one, Decimal::percent(0));
assert_eq!(Decimal::percent(1) / one, Decimal::percent(1));
assert_eq!(Decimal::percent(10) / one, Decimal::percent(10));
assert_eq!(Decimal::percent(100) / one, Decimal::percent(100));
assert_eq!(Decimal::percent(1000) / one, Decimal::percent(1000));
assert_eq!(two / Decimal::percent(1), Decimal::percent(20_000));
assert_eq!(two / Decimal::percent(10), Decimal::percent(2_000));
assert_eq!(two / Decimal::percent(100), Decimal::percent(200));
assert_eq!(two / Decimal::percent(1000), Decimal::percent(20));
assert_eq!(Decimal::percent(0) / two, Decimal::percent(0));
assert_eq!(Decimal::percent(1) / two, dec("0.005"));
assert_eq!(Decimal::percent(10) / two, Decimal::percent(5));
assert_eq!(Decimal::percent(100) / two, Decimal::percent(50));
assert_eq!(Decimal::percent(1000) / two, Decimal::percent(500));
assert_eq!(half / Decimal::percent(1), Decimal::percent(5_000));
assert_eq!(half / Decimal::percent(10), Decimal::percent(500));
assert_eq!(half / Decimal::percent(100), Decimal::percent(50));
assert_eq!(half / Decimal::percent(1000), Decimal::percent(5));
assert_eq!(Decimal::percent(0) / half, Decimal::percent(0));
assert_eq!(Decimal::percent(1) / half, Decimal::percent(2));
assert_eq!(Decimal::percent(10) / half, Decimal::percent(20));
assert_eq!(Decimal::percent(100) / half, Decimal::percent(200));
assert_eq!(Decimal::percent(1000) / half, Decimal::percent(2000));
let a = dec("123127726548762582");
assert_eq!(a / dec("1"), dec("123127726548762582"));
assert_eq!(a / dec("10"), dec("12312772654876258.2"));
assert_eq!(a / dec("100"), dec("1231277265487625.82"));
assert_eq!(a / dec("1000"), dec("123127726548762.582"));
assert_eq!(a / dec("1000000"), dec("123127726548.762582"));
assert_eq!(a / dec("1000000000"), dec("123127726.548762582"));
assert_eq!(a / dec("1000000000000"), dec("123127.726548762582"));
assert_eq!(a / dec("1000000000000000"), dec("123.127726548762582"));
assert_eq!(a / dec("1000000000000000000"), dec("0.123127726548762582"));
assert_eq!(dec("1") / a, dec("0.000000000000000008"));
assert_eq!(dec("10") / a, dec("0.000000000000000081"));
assert_eq!(dec("100") / a, dec("0.000000000000000812"));
assert_eq!(dec("1000") / a, dec("0.000000000000008121"));
assert_eq!(dec("1000000") / a, dec("0.000000000008121647"));
assert_eq!(dec("1000000000") / a, dec("0.000000008121647560"));
assert_eq!(dec("1000000000000") / a, dec("0.000008121647560868"));
assert_eq!(dec("1000000000000000") / a, dec("0.008121647560868164"));
assert_eq!(dec("1000000000000000000") / a, dec("8.121647560868164773"));
let a = dec("0.123127726548762582");
assert_eq!(a / dec("1.0"), dec("0.123127726548762582"));
assert_eq!(a / dec("0.1"), dec("1.23127726548762582"));
assert_eq!(a / dec("0.01"), dec("12.3127726548762582"));
assert_eq!(a / dec("0.001"), dec("123.127726548762582"));
assert_eq!(a / dec("0.000001"), dec("123127.726548762582"));
assert_eq!(a / dec("0.000000001"), dec("123127726.548762582"));
assert_eq!(a / dec("0.000000000001"), dec("123127726548.762582"));
assert_eq!(a / dec("0.000000000000001"), dec("123127726548762.582"));
assert_eq!(a / dec("0.000000000000000001"), dec("123127726548762582"));
assert_eq!(
Decimal::percent(15) / Decimal::percent(60),
Decimal::percent(25)
);
let a = Decimal::percent(100);
let b = Decimal::percent(20);
let expected = Decimal::percent(500);
assert_eq!(a / b, expected);
assert_eq!(&a / b, expected);
assert_eq!(a / &b, expected);
assert_eq!(&a / &b, expected);
}
#[test]
fn decimal_div_assign_works() {
let mut a = Decimal::percent(15);
a /= Decimal::percent(20);
assert_eq!(a, Decimal::percent(75));
let mut a = Decimal::percent(50);
let b = Decimal::percent(20);
a /= &b;
assert_eq!(a, Decimal::percent(250));
}
#[test]
#[should_panic(expected = "Division failed - multiplication overflow")]
fn decimal_div_overflow_panics() {
let _value = Decimal::MAX / Decimal::percent(10);
}
#[test]
#[should_panic(expected = "Division failed - denominator must not be zero")]
fn decimal_div_by_zero_panics() {
let _value = Decimal::one() / Decimal::zero();
}
#[test]
fn decimal_uint128_division() {
let left = Decimal::percent(150); let right = Uint128::new(3);
assert_eq!(left / right, Decimal::percent(50));
let left = Decimal::zero();
let right = Uint128::new(300);
assert_eq!(left / right, Decimal::zero());
}
#[test]
#[should_panic(expected = "attempt to divide by zero")]
fn decimal_uint128_divide_by_zero() {
let left = Decimal::percent(150); let right = Uint128::new(0);
let _result = left / right;
}
#[test]
fn decimal_uint128_div_assign() {
let mut dec = Decimal::percent(150); dec /= Uint128::new(3);
assert_eq!(dec, Decimal::percent(50));
let mut dec = Decimal::zero();
dec /= Uint128::new(300);
assert_eq!(dec, Decimal::zero());
}
#[test]
#[should_panic(expected = "attempt to divide by zero")]
fn decimal_uint128_div_assign_by_zero() {
let mut dec = Decimal::percent(50);
dec /= Uint128::new(0);
}
#[test]
fn decimal_uint128_sqrt() {
assert_eq!(Decimal::percent(0).sqrt(), Decimal::percent(0));
assert_eq!(Decimal::percent(900).sqrt(), Decimal::percent(300));
assert!(Decimal::percent(316) < Decimal::percent(1000).sqrt());
assert!(Decimal::percent(1000).sqrt() < Decimal::percent(317));
}
#[test]
fn decimal_uint128_sqrt_is_precise() {
assert_eq!(
Decimal::from_str("2").unwrap().sqrt(),
Decimal::from_str("1.414213562373095048").unwrap() );
}
#[test]
fn decimal_uint128_sqrt_does_not_overflow() {
assert_eq!(
Decimal::from_str("400").unwrap().sqrt(),
Decimal::from_str("20").unwrap()
);
}
#[test]
fn decimal_uint128_sqrt_intermediate_precision_used() {
assert_eq!(
Decimal::from_str("400001").unwrap().sqrt(),
Decimal::from_str("632.456322602596803200").unwrap()
);
}
#[test]
fn decimal_checked_pow() {
for exp in 0..10 {
assert_eq!(Decimal::one().checked_pow(exp).unwrap(), Decimal::one());
}
assert_eq!(Decimal::zero().checked_pow(0).unwrap(), Decimal::one());
for exp in 1..10 {
assert_eq!(Decimal::zero().checked_pow(exp).unwrap(), Decimal::zero());
}
for num in &[
Decimal::percent(50),
Decimal::percent(99),
Decimal::percent(200),
] {
assert_eq!(num.checked_pow(0).unwrap(), Decimal::one())
}
assert_eq!(
Decimal::percent(20).checked_pow(2).unwrap(),
Decimal::percent(4)
);
assert_eq!(
Decimal::percent(20).checked_pow(3).unwrap(),
Decimal::permille(8)
);
assert_eq!(
Decimal::percent(200).checked_pow(4).unwrap(),
Decimal::percent(1600)
);
assert_eq!(
Decimal::percent(200).checked_pow(4).unwrap(),
Decimal::percent(1600)
);
assert_eq!(
Decimal::percent(700).checked_pow(5).unwrap(),
Decimal::percent(1680700)
);
assert_eq!(
Decimal::percent(700).checked_pow(8).unwrap(),
Decimal::percent(576480100)
);
assert_eq!(
Decimal::percent(700).checked_pow(10).unwrap(),
Decimal::percent(28247524900)
);
assert_eq!(
Decimal::percent(120).checked_pow(123).unwrap(),
Decimal::new(5486473221892422150877397607u128.into())
);
assert_eq!(
Decimal::percent(10).checked_pow(2).unwrap(),
Decimal::new(10000000000000000u128.into())
);
assert_eq!(
Decimal::percent(10).checked_pow(18).unwrap(),
Decimal::new(1u128.into())
);
}
#[test]
fn decimal_checked_pow_overflow() {
assert_eq!(
Decimal::MAX.checked_pow(2),
Err(OverflowError::new(OverflowOperation::Pow))
);
assert_eq!(
Decimal::MAX.checked_pow(3),
Err(OverflowError::new(OverflowOperation::Pow))
);
assert_eq!(
Decimal::new(DECIMAL_FRACTIONAL * Uint128::new(1_000_000_000)).checked_pow(15),
Err(OverflowError::new(OverflowOperation::Pow))
);
}
#[test]
fn decimal_to_string() {
assert_eq!(Decimal::zero().to_string(), "0");
assert_eq!(Decimal::one().to_string(), "1");
assert_eq!(Decimal::percent(500).to_string(), "5");
assert_eq!(Decimal::percent(125).to_string(), "1.25");
assert_eq!(Decimal::percent(42638).to_string(), "426.38");
assert_eq!(Decimal::percent(3).to_string(), "0.03");
assert_eq!(Decimal::permille(987).to_string(), "0.987");
assert_eq!(
Decimal::new(Uint128::from(1u128)).to_string(),
"0.000000000000000001"
);
assert_eq!(
Decimal::new(Uint128::from(10u128)).to_string(),
"0.00000000000000001"
);
assert_eq!(
Decimal::new(Uint128::from(100u128)).to_string(),
"0.0000000000000001"
);
assert_eq!(
Decimal::new(Uint128::from(1000u128)).to_string(),
"0.000000000000001"
);
assert_eq!(
Decimal::new(Uint128::from(10000u128)).to_string(),
"0.00000000000001"
);
assert_eq!(
Decimal::new(Uint128::from(100000u128)).to_string(),
"0.0000000000001"
);
assert_eq!(
Decimal::new(Uint128::from(1000000u128)).to_string(),
"0.000000000001"
);
assert_eq!(
Decimal::new(Uint128::from(10000000u128)).to_string(),
"0.00000000001"
);
assert_eq!(
Decimal::new(Uint128::from(100000000u128)).to_string(),
"0.0000000001"
);
assert_eq!(
Decimal::new(Uint128::from(1000000000u128)).to_string(),
"0.000000001"
);
assert_eq!(
Decimal::new(Uint128::from(10000000000u128)).to_string(),
"0.00000001"
);
assert_eq!(
Decimal::new(Uint128::from(100000000000u128)).to_string(),
"0.0000001"
);
assert_eq!(
Decimal::new(Uint128::from(10000000000000u128)).to_string(),
"0.00001"
);
assert_eq!(
Decimal::new(Uint128::from(100000000000000u128)).to_string(),
"0.0001"
);
assert_eq!(
Decimal::new(Uint128::from(1000000000000000u128)).to_string(),
"0.001"
);
assert_eq!(
Decimal::new(Uint128::from(10000000000000000u128)).to_string(),
"0.01"
);
assert_eq!(
Decimal::new(Uint128::from(100000000000000000u128)).to_string(),
"0.1"
);
}
#[test]
fn decimal_iter_sum() {
let items = vec![
Decimal::zero(),
Decimal::new(Uint128::from(2u128)),
Decimal::new(Uint128::from(2u128)),
];
assert_eq!(
items.iter().sum::<Decimal>(),
Decimal::new(Uint128::from(4u128))
);
assert_eq!(
items.into_iter().sum::<Decimal>(),
Decimal::new(Uint128::from(4u128))
);
let empty: Vec<Decimal> = vec![];
assert_eq!(Decimal::zero(), empty.iter().sum::<Decimal>());
}
#[test]
fn decimal_serialize() {
assert_eq!(serde_json::to_vec(&Decimal::zero()).unwrap(), br#""0""#);
assert_eq!(serde_json::to_vec(&Decimal::one()).unwrap(), br#""1""#);
assert_eq!(
serde_json::to_vec(&Decimal::percent(8)).unwrap(),
br#""0.08""#
);
assert_eq!(
serde_json::to_vec(&Decimal::percent(87)).unwrap(),
br#""0.87""#
);
assert_eq!(
serde_json::to_vec(&Decimal::percent(876)).unwrap(),
br#""8.76""#
);
assert_eq!(
serde_json::to_vec(&Decimal::percent(8765)).unwrap(),
br#""87.65""#
);
}
#[test]
fn decimal_deserialize() {
assert_eq!(
serde_json::from_slice::<Decimal>(br#""0""#).unwrap(),
Decimal::zero()
);
assert_eq!(
serde_json::from_slice::<Decimal>(br#""1""#).unwrap(),
Decimal::one()
);
assert_eq!(
serde_json::from_slice::<Decimal>(br#""000""#).unwrap(),
Decimal::zero()
);
assert_eq!(
serde_json::from_slice::<Decimal>(br#""001""#).unwrap(),
Decimal::one()
);
assert_eq!(
serde_json::from_slice::<Decimal>(br#""0.08""#).unwrap(),
Decimal::percent(8)
);
assert_eq!(
serde_json::from_slice::<Decimal>(br#""0.87""#).unwrap(),
Decimal::percent(87)
);
assert_eq!(
serde_json::from_slice::<Decimal>(br#""8.76""#).unwrap(),
Decimal::percent(876)
);
assert_eq!(
serde_json::from_slice::<Decimal>(br#""87.65""#).unwrap(),
Decimal::percent(8765)
);
}
#[test]
fn decimal_abs_diff_works() {
let a = Decimal::percent(285);
let b = Decimal::percent(200);
let expected = Decimal::percent(85);
assert_eq!(a.abs_diff(b), expected);
assert_eq!(b.abs_diff(a), expected);
}
#[test]
#[allow(clippy::op_ref)]
fn decimal_rem_works() {
assert_eq!(
Decimal::percent(402) % Decimal::percent(111),
Decimal::percent(69)
);
assert_eq!(
Decimal::percent(1525) % Decimal::percent(400),
Decimal::percent(325)
);
let a = Decimal::percent(318);
let b = Decimal::percent(317);
let expected = Decimal::percent(1);
assert_eq!(a % b, expected);
assert_eq!(a % &b, expected);
assert_eq!(&a % b, expected);
assert_eq!(&a % &b, expected);
}
#[test]
fn decimal_rem_assign_works() {
let mut a = Decimal::percent(17673);
a %= Decimal::percent(2362);
assert_eq!(a, Decimal::percent(1139));
let mut a = Decimal::percent(4262);
let b = Decimal::percent(1270);
a %= &b;
assert_eq!(a, Decimal::percent(452)); }
#[test]
#[should_panic(expected = "divisor of zero")]
fn decimal_rem_panics_for_zero() {
let _ = Decimal::percent(777) % Decimal::zero();
}
#[test]
fn decimal_checked_methods() {
assert_eq!(
Decimal::percent(402)
.checked_add(Decimal::percent(111))
.unwrap(),
Decimal::percent(513)
);
assert!(matches!(
Decimal::MAX.checked_add(Decimal::percent(1)),
Err(OverflowError { .. })
));
assert_eq!(
Decimal::percent(1111)
.checked_sub(Decimal::percent(111))
.unwrap(),
Decimal::percent(1000)
);
assert!(matches!(
Decimal::zero().checked_sub(Decimal::percent(1)),
Err(OverflowError { .. })
));
assert_eq!(
Decimal::percent(30)
.checked_div(Decimal::percent(200))
.unwrap(),
Decimal::percent(15)
);
assert_eq!(
Decimal::percent(88)
.checked_div(Decimal::percent(20))
.unwrap(),
Decimal::percent(440)
);
assert!(matches!(
Decimal::MAX.checked_div(Decimal::zero()),
Err(CheckedFromRatioError::DivideByZero)
));
assert!(matches!(
Decimal::MAX.checked_div(Decimal::percent(1)),
Err(CheckedFromRatioError::Overflow)
));
assert_eq!(
Decimal::percent(402)
.checked_rem(Decimal::percent(111))
.unwrap(),
Decimal::percent(69)
);
assert_eq!(
Decimal::percent(1525)
.checked_rem(Decimal::percent(400))
.unwrap(),
Decimal::percent(325)
);
assert!(matches!(
Decimal::MAX.checked_rem(Decimal::zero()),
Err(DivideByZeroError { .. })
));
}
#[test]
fn decimal_pow_works() {
assert_eq!(Decimal::percent(200).pow(2), Decimal::percent(400));
assert_eq!(Decimal::percent(200).pow(10), Decimal::percent(102400));
}
#[test]
#[should_panic]
fn decimal_pow_overflow_panics() {
_ = Decimal::MAX.pow(2u32);
}
#[test]
fn decimal_saturating_works() {
assert_eq!(
Decimal::percent(200).saturating_add(Decimal::percent(200)),
Decimal::percent(400)
);
assert_eq!(
Decimal::MAX.saturating_add(Decimal::percent(200)),
Decimal::MAX
);
assert_eq!(
Decimal::percent(200).saturating_sub(Decimal::percent(100)),
Decimal::percent(100)
);
assert_eq!(
Decimal::zero().saturating_sub(Decimal::percent(200)),
Decimal::zero()
);
assert_eq!(
Decimal::percent(200).saturating_mul(Decimal::percent(50)),
Decimal::percent(100)
);
assert_eq!(
Decimal::MAX.saturating_mul(Decimal::percent(200)),
Decimal::MAX
);
assert_eq!(
Decimal::percent(400).saturating_pow(2u32),
Decimal::percent(1600)
);
assert_eq!(Decimal::MAX.saturating_pow(2u32), Decimal::MAX);
}
#[test]
fn decimal_rounding() {
assert_eq!(Decimal::one().floor(), Decimal::one());
assert_eq!(Decimal::percent(150).floor(), Decimal::one());
assert_eq!(Decimal::percent(199).floor(), Decimal::one());
assert_eq!(Decimal::percent(200).floor(), Decimal::percent(200));
assert_eq!(Decimal::percent(99).floor(), Decimal::zero());
assert_eq!(Decimal::one().ceil(), Decimal::one());
assert_eq!(Decimal::percent(150).ceil(), Decimal::percent(200));
assert_eq!(Decimal::percent(199).ceil(), Decimal::percent(200));
assert_eq!(Decimal::percent(99).ceil(), Decimal::one());
assert_eq!(Decimal::new(Uint128::from(1u128)).ceil(), Decimal::one());
}
#[test]
#[should_panic(expected = "attempt to ceil with overflow")]
fn decimal_ceil_panics() {
let _ = Decimal::MAX.ceil();
}
#[test]
fn decimal_checked_ceil() {
assert_eq!(
Decimal::percent(199).checked_ceil(),
Ok(Decimal::percent(200))
);
assert!(matches!(
Decimal::MAX.checked_ceil(),
Err(RoundUpOverflowError { .. })
));
}
#[test]
fn decimal_to_uint_floor_works() {
let d = Decimal::from_str("12.000000000000000001").unwrap();
assert_eq!(d.to_uint_floor(), Uint128::new(12));
let d = Decimal::from_str("12.345").unwrap();
assert_eq!(d.to_uint_floor(), Uint128::new(12));
let d = Decimal::from_str("12.999").unwrap();
assert_eq!(d.to_uint_floor(), Uint128::new(12));
let d = Decimal::from_str("0.98451384").unwrap();
assert_eq!(d.to_uint_floor(), Uint128::new(0));
let d = Decimal::from_str("75.0").unwrap();
assert_eq!(d.to_uint_floor(), Uint128::new(75));
let d = Decimal::from_str("0.0").unwrap();
assert_eq!(d.to_uint_floor(), Uint128::new(0));
let d = Decimal::MAX;
assert_eq!(d.to_uint_floor(), Uint128::new(340282366920938463463));
let tests = vec![
(Decimal::from_str("12.345").unwrap(), 12u128),
(Decimal::from_str("0.98451384").unwrap(), 0u128),
(Decimal::from_str("178.0").unwrap(), 178u128),
(Decimal::MIN, 0u128),
(Decimal::MAX, u128::MAX / DECIMAL_FRACTIONAL.u128()),
];
for (my_decimal, expected) in tests.into_iter() {
assert_eq!(my_decimal.to_uint_floor(), Uint128::new(expected));
}
}
#[test]
fn decimal_to_uint_ceil_works() {
let d = Decimal::from_str("12.000000000000000001").unwrap();
assert_eq!(d.to_uint_ceil(), Uint128::new(13));
let d = Decimal::from_str("12.345").unwrap();
assert_eq!(d.to_uint_ceil(), Uint128::new(13));
let d = Decimal::from_str("12.999").unwrap();
assert_eq!(d.to_uint_ceil(), Uint128::new(13));
let d = Decimal::from_str("75.0").unwrap();
assert_eq!(d.to_uint_ceil(), Uint128::new(75));
let d = Decimal::from_str("0.0").unwrap();
assert_eq!(d.to_uint_ceil(), Uint128::new(0));
let d = Decimal::MAX;
assert_eq!(d.to_uint_ceil(), Uint128::new(340282366920938463464));
}
#[test]
fn decimal_partial_eq() {
let test_cases = [
("1", "1", true),
("0.5", "0.5", true),
("0.5", "0.51", false),
("0", "0.00000", true),
]
.into_iter()
.map(|(lhs, rhs, expected)| (dec(lhs), dec(rhs), expected));
#[allow(clippy::op_ref)]
for (lhs, rhs, expected) in test_cases {
assert_eq!(lhs == rhs, expected);
assert_eq!(&lhs == rhs, expected);
assert_eq!(lhs == &rhs, expected);
assert_eq!(&lhs == &rhs, expected);
}
}
#[test]
fn decimal_implements_debug() {
let decimal = Decimal::from_str("123.45").unwrap();
assert_eq!(format!("{decimal:?}"), "Decimal(123.45)");
let test_cases = ["5", "5.01", "42", "0", "2"];
for s in test_cases {
let decimal = Decimal::from_str(s).unwrap();
let expected = format!("Decimal({s})");
assert_eq!(format!("{decimal:?}"), expected);
}
}
#[test]
fn serialize_decimal_to_string() {
let d = Decimal::from_str("123.45").unwrap();
let json_string = serde_json::to_string(&d).unwrap();
assert_eq!(r#""123.45""#, json_string);
}
#[test]
fn deserialize_decimal_from_string() {
let json_string = r#""123.45""#;
let d: Decimal = serde_json::from_str(json_string).unwrap();
assert_eq!(d, Decimal::from_str("123.45").unwrap());
}
#[test]
fn deserialize_invalid_decimal() {
let json_string = r#""123,45""#;
let result: Result<Decimal, _> = serde_json::from_str(json_string);
let err = result.unwrap_err();
assert!(err.to_string().contains("invalid digit"));
}
#[test]
fn deserialize_wrong_type_triggers_expectation() {
let json_decimal = "123.45";
let err = serde_json::from_str::<Decimal>(json_decimal).unwrap_err();
assert!(err.to_string().contains("expected string-encoded decimal"));
}
#[test]
fn failing_writer_should_work() {
enum When {
Always,
OnDecimal,
AfterDecimal,
}
struct FailingWriter {
when: When,
consumed_decimal: bool,
}
impl FailingWriter {
fn new(when: When) -> Self {
Self {
when,
consumed_decimal: false,
}
}
}
impl Write for FailingWriter {
fn write_str(&mut self, s: &str) -> std::fmt::Result {
match self.when {
When::Always => return Err(std::fmt::Error),
When::OnDecimal => {
if s == "." {
return Err(std::fmt::Error);
}
}
When::AfterDecimal => {
if self.consumed_decimal {
return Err(std::fmt::Error);
}
if s == "." {
self.consumed_decimal = true;
}
}
}
Ok(())
}
}
write!(
&mut FailingWriter::new(When::Always),
"{}",
Decimal::from_str("123.456").unwrap()
)
.unwrap_err();
write!(
&mut FailingWriter::new(When::OnDecimal),
"{}",
Decimal::from_str("123.456").unwrap()
)
.unwrap_err();
write!(
&mut FailingWriter::new(When::AfterDecimal),
"{}",
Decimal::from_str("123.456").unwrap()
)
.unwrap_err();
}