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// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
use core::ops::RangeInclusive;
use fixed_decimal::UnsignedDecimal;
use fixed_decimal::UnsignedRoundingMode;
use writeable::Writeable;
#[test]
pub fn test_ecma402_table() {
// Source: <https://tc39.es/ecma402/#table-intl-rounding-modes>
let cases: [(_, _, _, _, _, _); 5] = [
("expand", UnsignedRoundingMode::Expand, 1, 1, 1, 2),
("trunc", UnsignedRoundingMode::Trunc, 0, 0, 0, 1),
("half_expand", UnsignedRoundingMode::HalfExpand, 0, 1, 1, 2),
("half_trunc", UnsignedRoundingMode::HalfTrunc, 0, 0, 1, 1),
("half_even", UnsignedRoundingMode::HalfEven, 0, 0, 1, 2),
];
for (name, mode, e2, e3, e4, e5) in cases {
let mut fd2: UnsignedDecimal = "0.4".parse().unwrap();
let mut fd3: UnsignedDecimal = "0.5".parse().unwrap();
let mut fd4: UnsignedDecimal = "0.6".parse().unwrap();
let mut fd5: UnsignedDecimal = "1.5".parse().unwrap();
fd2.round_with_mode(0, mode);
fd3.round_with_mode(0, mode);
fd4.round_with_mode(0, mode);
fd5.round_with_mode(0, mode);
assert_eq!(
fd2.write_to_string(),
e2.write_to_string(),
"0.4 failed for {name}"
);
assert_eq!(
fd3.write_to_string(),
e3.write_to_string(),
"0.5 failed for {name}"
);
assert_eq!(
fd4.write_to_string(),
e4.write_to_string(),
"0.6 failed for {name}"
);
assert_eq!(
fd5.write_to_string(),
e5.write_to_string(),
"1.5 failed for {name}"
);
}
}
#[test]
pub fn test_within_ranges() {
struct TestCase {
rounding_mode_name: &'static str,
rounding_mode: UnsignedRoundingMode,
range_0: RangeInclusive<u32>,
range_1000: RangeInclusive<u32>,
range_2000: RangeInclusive<u32>,
}
let cases: [TestCase; 5] = [
TestCase {
rounding_mode_name: "expand",
rounding_mode: UnsignedRoundingMode::Expand,
range_0: 0..=0,
range_1000: 1..=1000,
range_2000: 1001..=2000,
},
TestCase {
rounding_mode_name: "trunc",
rounding_mode: UnsignedRoundingMode::Trunc,
range_0: 0..=999,
range_1000: 1000..=1999,
range_2000: 2000..=2999,
},
TestCase {
rounding_mode_name: "half_expand",
rounding_mode: UnsignedRoundingMode::HalfExpand,
range_0: 0..=449,
range_1000: 500..=1449,
range_2000: 1500..=2449,
},
TestCase {
rounding_mode_name: "half_trunc",
rounding_mode: UnsignedRoundingMode::HalfTrunc,
range_0: 0..=500,
range_1000: 501..=1500,
range_2000: 1501..=2500,
},
TestCase {
rounding_mode_name: "half_even",
rounding_mode: UnsignedRoundingMode::HalfEven,
range_0: 0..=500,
range_1000: 501..=1449,
range_2000: 1500..=2500,
},
];
for TestCase {
rounding_mode_name,
rounding_mode,
range_0,
range_1000,
range_2000,
} in cases
{
for n in range_0 {
let mut fd = UnsignedDecimal::from(n);
fd.round_with_mode(3, rounding_mode);
assert_eq!(fd.write_to_string(), "000", "{rounding_mode_name}: {n}");
let (mut fd, expected) = (
UnsignedDecimal::from(n + 1000000).multiplied_pow10(-5),
"10.00",
);
fd.round_with_mode(-2, rounding_mode);
assert_eq!(
fd.write_to_string(),
expected,
"{rounding_mode_name}: {n} ÷ 10^5 ± 10"
);
}
for n in range_1000 {
let mut fd = UnsignedDecimal::from(n);
fd.round_with_mode(3, rounding_mode);
assert_eq!(fd.write_to_string(), "1000", "{rounding_mode_name}: {n}");
let mut fd = UnsignedDecimal::from(n + 1000000).multiplied_pow10(-5);
fd.round_with_mode(-2, rounding_mode);
assert_eq!(
fd.write_to_string(),
"10.01",
"{rounding_mode_name}: {n} ÷ 10^5 ± 10"
);
}
for n in range_2000 {
let mut fd = UnsignedDecimal::from(n);
fd.round_with_mode(3, rounding_mode);
assert_eq!(fd.write_to_string(), "2000", "{rounding_mode_name}: {n}");
let mut fd = UnsignedDecimal::from(n + 1000000).multiplied_pow10(-5);
fd.round_with_mode(-2, rounding_mode);
assert_eq!(
fd.write_to_string(),
"10.02",
"{rounding_mode_name}: {n} ÷ 10^5 ± 10"
);
}
}
}
#[test]
pub fn extra_rounding_mode_cases() {
struct TestCase {
input: &'static str,
position: i16,
// expand, trunc, half_expand, half_trunc, half_even
all_expected: [&'static str; 5],
}
let cases: [TestCase; 8] = [
TestCase {
input: "505.050",
position: -3,
all_expected: ["505.050", "505.050", "505.050", "505.050", "505.050"],
},
TestCase {
input: "505.050",
position: -2,
all_expected: ["505.05", "505.05", "505.05", "505.05", "505.05"],
},
TestCase {
input: "505.050",
position: -1,
all_expected: ["505.1", "505.0", "505.1", "505.0", "505.0"],
},
TestCase {
input: "505.050",
position: 0,
all_expected: ["506", "505", "505", "505", "505"],
},
TestCase {
input: "505.050",
position: 1,
all_expected: ["510", "500", "510", "510", "510"],
},
TestCase {
input: "505.050",
position: 2,
all_expected: ["600", "500", "500", "500", "500"],
},
TestCase {
input: "505.050",
position: 3,
all_expected: ["1000", "000", "1000", "1000", "1000"],
},
TestCase {
input: "505.050",
position: 4,
all_expected: ["10000", "0000", "0000", "0000", "0000"],
},
];
let rounding_modes: [(&'static str, UnsignedRoundingMode); 5] = [
("expand", UnsignedRoundingMode::Expand),
("trunc", UnsignedRoundingMode::Trunc),
("half_expand", UnsignedRoundingMode::HalfExpand),
("half_trunc", UnsignedRoundingMode::HalfTrunc),
("half_even", UnsignedRoundingMode::HalfEven),
];
for TestCase {
input,
position,
all_expected,
} in cases
{
for ((rounding_mode_name, rounding_mode), expected) in
rounding_modes.iter().zip(all_expected.iter())
{
let mut fd: UnsignedDecimal = input.parse().unwrap();
fd.round_with_mode(position, *rounding_mode);
assert_eq!(
&*fd.write_to_string(),
*expected,
"{input}: {rounding_mode_name} @ {position}"
)
}
}
}
#[test]
pub fn test_ecma402_table_with_increments() {
use fixed_decimal::RoundingIncrement;
#[rustfmt::skip] // Don't split everything on its own line. Makes it look a lot nicer.
let cases: [(_, _, [(_, _, _, _, _, _); 5]); 3] = [
("two", RoundingIncrement::MultiplesOf2, [
("expand", UnsignedRoundingMode::Expand, "0.4", "0.6", "0.6", "1.6"),
("trunc", UnsignedRoundingMode::Trunc, "0.4", "0.4", "0.6", "1.4"),
("half_expand", UnsignedRoundingMode::HalfExpand, "0.4", "0.6", "0.6", "1.6"),
("half_trunc", UnsignedRoundingMode::HalfTrunc, "0.4", "0.4", "0.6", "1.4"),
("half_even", UnsignedRoundingMode::HalfEven, "0.4", "0.4", "0.6", "1.6"),
]),
("five", RoundingIncrement::MultiplesOf5, [
("expand", UnsignedRoundingMode::Expand, "0.5", "0.5", "1.0", "1.5"),
("trunc", UnsignedRoundingMode::Trunc, "0.0", "0.5", "0.5", "1.5"),
("half_expand", UnsignedRoundingMode::HalfExpand, "0.5", "0.5", "0.5", "1.5"),
("half_trunc", UnsignedRoundingMode::HalfTrunc, "0.5", "0.5", "0.5", "1.5"),
("half_even", UnsignedRoundingMode::HalfEven, "0.5", "0.5", "0.5", "1.5"),
]),
("twenty-five", RoundingIncrement::MultiplesOf25, [
("expand", UnsignedRoundingMode::Expand, "2.5", "2.5", "2.5", "2.5"),
("trunc", UnsignedRoundingMode::Trunc, "0.0", "0.0", "0.0", "0.0"),
("half_expand", UnsignedRoundingMode::HalfExpand, "0.0", "0.0", "0.0", "2.5"),
("half_trunc", UnsignedRoundingMode::HalfTrunc, "0.0", "0.0", "0.0", "2.5"),
("half_even", UnsignedRoundingMode::HalfEven, "0.0", "0.0", "0.0", "2.5"),
]),
];
for (increment_str, increment, cases) in cases {
for (rounding_mode_name, rounding_mode, e2, e3, e4, e5) in cases {
let mut fd2: UnsignedDecimal = "0.4".parse().unwrap();
let mut fd3: UnsignedDecimal = "0.5".parse().unwrap();
let mut fd4: UnsignedDecimal = "0.6".parse().unwrap();
let mut fd5: UnsignedDecimal = "1.5".parse().unwrap();
// The original ECMA-402 table tests rounding at magnitude 0.
// However, testing rounding at magnitude -1 gives more
// interesting test cases for increments.
fd2.round_with_mode_and_increment(-1, rounding_mode, increment);
fd3.round_with_mode_and_increment(-1, rounding_mode, increment);
fd4.round_with_mode_and_increment(-1, rounding_mode, increment);
fd5.round_with_mode_and_increment(-1, rounding_mode, increment);
assert_eq!(
fd2.write_to_string(),
e2,
"0.4 failed for {rounding_mode_name} with increments of {increment_str}"
);
assert_eq!(
fd3.write_to_string(),
e3,
"0.5 failed for {rounding_mode_name} with increments of {increment_str}"
);
assert_eq!(
fd4.write_to_string(),
e4,
"0.6 failed for {rounding_mode_name} with increments of {increment_str}"
);
assert_eq!(
fd5.write_to_string(),
e5,
"1.5 failed for {rounding_mode_name} with increments of {increment_str}"
);
}
}
}
|
