ladybird/Tests/AK/TestStdLibExtras.cpp
Nico Weber 88d0702763 AK: Make ceil_div() handle one argument being negative correctly
`ceil_div(-1, 2)` used to return -1.
Now it returns 0, which is the correct ceil(-0.5).

(C++'s division semantics have floor semantics for numbers > 0,
but ceil semantics for numbers < 0.)

This will be important for the JPEG2000 decoder eventually.
2024-04-27 07:09:08 +02:00

121 lines
2.7 KiB
C++

/*
* Copyright (c) 2021, Tim Flynn <trflynn89@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestSuite.h>
#include <AK/Optional.h>
#include <AK/StdLibExtras.h>
#include <AK/StringView.h>
#include <AK/Variant.h>
#include <AK/Vector.h>
TEST_CASE(ceil_div)
{
EXPECT_EQ(ceil_div(0, 1), 0);
EXPECT_EQ(ceil_div(1, 1), 1);
EXPECT_EQ(ceil_div(2, 1), 2);
EXPECT_EQ(ceil_div(3, 1), 3);
EXPECT_EQ(ceil_div(4, 1), 4);
EXPECT_EQ(ceil_div(-0, 1), 0);
EXPECT_EQ(ceil_div(-1, 1), -1);
EXPECT_EQ(ceil_div(-2, 1), -2);
EXPECT_EQ(ceil_div(-3, 1), -3);
EXPECT_EQ(ceil_div(-4, 1), -4);
EXPECT_EQ(ceil_div(0, -1), 0);
EXPECT_EQ(ceil_div(1, -1), -1);
EXPECT_EQ(ceil_div(2, -1), -2);
EXPECT_EQ(ceil_div(3, -1), -3);
EXPECT_EQ(ceil_div(4, -1), -4);
EXPECT_EQ(ceil_div(-0, -1), 0);
EXPECT_EQ(ceil_div(-1, -1), 1);
EXPECT_EQ(ceil_div(-2, -1), 2);
EXPECT_EQ(ceil_div(-3, -1), 3);
EXPECT_EQ(ceil_div(-4, -1), 4);
EXPECT_EQ(ceil_div(0, 2), 0);
EXPECT_EQ(ceil_div(1, 2), 1);
EXPECT_EQ(ceil_div(2, 2), 1);
EXPECT_EQ(ceil_div(3, 2), 2);
EXPECT_EQ(ceil_div(4, 2), 2);
EXPECT_EQ(ceil_div(-0, 2), 0);
EXPECT_EQ(ceil_div(-1, 2), 0);
EXPECT_EQ(ceil_div(-2, 2), -1);
EXPECT_EQ(ceil_div(-3, 2), -1);
EXPECT_EQ(ceil_div(-4, 2), -2);
EXPECT_EQ(ceil_div(0, -2), 0);
EXPECT_EQ(ceil_div(1, -2), 0);
EXPECT_EQ(ceil_div(2, -2), -1);
EXPECT_EQ(ceil_div(3, -2), -1);
EXPECT_EQ(ceil_div(4, -2), -2);
EXPECT_EQ(ceil_div(-0, -2), 0);
EXPECT_EQ(ceil_div(-1, -2), 1);
EXPECT_EQ(ceil_div(-2, -2), 1);
EXPECT_EQ(ceil_div(-3, -2), 2);
EXPECT_EQ(ceil_div(-4, -2), 2);
}
TEST_CASE(mix)
{
double a = 1.0;
double b = 3.0;
EXPECT_APPROXIMATE(mix(a, b, 0.0), 1.0);
EXPECT_APPROXIMATE(mix(a, b, 0.5), 2.0);
EXPECT_APPROXIMATE(mix(a, b, 1.0), 3.0);
EXPECT_APPROXIMATE(mix(b, a, 0.0), 3.0);
EXPECT_APPROXIMATE(mix(b, a, 0.5), 2.0);
EXPECT_APPROXIMATE(mix(b, a, 1.0), 1.0);
}
TEST_CASE(swap)
{
int i = 4;
int j = 6;
swap(i, j);
EXPECT_EQ(i, 6);
EXPECT_EQ(j, 4);
}
TEST_CASE(swap_same_value)
{
int i = 4;
swap(i, i);
EXPECT_EQ(i, 4);
}
TEST_CASE(swap_same_complex_object)
{
struct Type1 {
StringView foo;
};
struct Type2 {
Optional<Type1> foo;
Vector<Type1> bar;
};
Variant<Type1, Type2> value1 { Type1 { "hello"sv } };
Variant<Type1, Type2> value2 { Type2 { {}, { { "goodbye"sv } } } };
swap(value1, value2);
EXPECT(value1.has<Type2>());
EXPECT(value2.has<Type1>());
swap(value1, value1);
EXPECT(value1.has<Type2>());
EXPECT(value2.has<Type1>());
}