ladybird/Tests/AK/TestBinarySearch.cpp
2021-05-06 17:54:28 +02:00

118 lines
2.8 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestCase.h>
#include <AK/BinarySearch.h>
#include <AK/Span.h>
#include <cstring>
#include <new>
TEST_CASE(vector_ints)
{
Vector<int> ints;
ints.append(1);
ints.append(2);
ints.append(3);
auto test1 = *binary_search(ints, 1);
auto test2 = *binary_search(ints, 2);
auto test3 = *binary_search(ints, 3);
EXPECT_EQ(test1, 1);
EXPECT_EQ(test2, 2);
EXPECT_EQ(test3, 3);
}
TEST_CASE(span_rvalue_reference)
{
Array<long, 3> array { 1, 2, 3 };
size_t nearby_index = 0;
auto* pointer = binary_search(array.span(), 2, &nearby_index);
EXPECT_EQ(nearby_index, 1u);
EXPECT_EQ(pointer, &array[1]);
}
TEST_CASE(array_doubles)
{
Array<double, 3> array { 1.1, 9.9, 33.33 };
EXPECT_EQ(binary_search(array, 1.1), &array[0]);
EXPECT_EQ(binary_search(array, 33.33), &array[2]);
EXPECT_EQ(binary_search(array, 9.9), &array[1]);
}
TEST_CASE(vector_strings)
{
Vector<String> strings;
strings.append("bat");
strings.append("cat");
strings.append("dog");
auto string_compare = [](const String& a, const String& b) -> int {
return strcmp(a.characters(), b.characters());
};
auto test1 = *binary_search(strings, String("bat"), nullptr, string_compare);
auto test2 = *binary_search(strings, String("cat"), nullptr, string_compare);
auto test3 = *binary_search(strings, String("dog"), nullptr, string_compare);
EXPECT_EQ(test1, String("bat"));
EXPECT_EQ(test2, String("cat"));
EXPECT_EQ(test3, String("dog"));
}
TEST_CASE(single_element)
{
Vector<int> ints;
ints.append(1);
auto test1 = *binary_search(ints, 1);
EXPECT_EQ(test1, 1);
}
TEST_CASE(not_found)
{
Vector<int> ints;
ints.append(1);
ints.append(2);
ints.append(3);
auto test1 = binary_search(ints, -1);
auto test2 = binary_search(ints, 0);
auto test3 = binary_search(ints, 4);
EXPECT_EQ(test1, nullptr);
EXPECT_EQ(test2, nullptr);
EXPECT_EQ(test3, nullptr);
}
TEST_CASE(no_elements)
{
Vector<int> ints;
auto test1 = binary_search(ints, 1);
EXPECT_EQ(test1, nullptr);
}
TEST_CASE(constexpr_array_search)
{
constexpr Array<int, 3> array = { 1, 17, 42 };
static_assert(binary_search(array, 42) == &array[2]);
static_assert(binary_search(array, 17) == &array[1]);
static_assert(binary_search(array, 3) == nullptr);
}
TEST_CASE(unsigned_to_signed_regression)
{
const Array<u32, 5> input { 0, 1, 2, 3, 4 };
// The algorithm computes 1 - input[2] = -1, and if this is (incorrectly) cast
// to an unsigned then it will look in the wrong direction and miss the 1.
size_t nearby_index = 1;
EXPECT_EQ(binary_search(input, 1u, &nearby_index), &input[1]);
EXPECT_EQ(nearby_index, 1u);
}