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◆ main openmsx / src / unittest / find_closest_test.cc
1.8 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#include "catch.hpp"
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#include "find_closest.h"
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#include <array>
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#include <chrono>
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#include <functional>
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#include <vector>
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TEST_CASE("find_closest_basic_integer_cases")
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{
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	std::vector values = {2, 5, 9, 13, 21};
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	SECTION("exact match returns zero distance")
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	{
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		auto [it, dist] = find_closest(values, 9);
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		CHECK(it == values.begin() + 2);
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		CHECK(dist == 0);
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	}
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	SECTION("before first element")
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	{
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		auto [it, dist] = find_closest(values, -3);
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		CHECK(it == values.begin());
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		CHECK(dist == 5);
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	}
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	SECTION("after last element")
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	{
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		auto [it, dist] = find_closest(values, 99);
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		CHECK(it == values.end() - 1);
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		CHECK(dist == 78);
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	}
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	SECTION("tie prefers earlier element")
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	{
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		auto [it, dist] = find_closest(values, 7);
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		CHECK(it == values.begin() + 1); // 5 beats 9 when distances tie
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		CHECK(dist == 2);
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	}
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	SECTION("middle selects nearest neighbour")
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	{
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		auto [it, dist] = find_closest(values, 12);
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		CHECK(it == values.begin() + 3); // 13 is closest to 12
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		CHECK(dist == 1);
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	}
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}
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TEST_CASE("find_closest_handles_empty_range")
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{
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	std::vector<int> empty;
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	auto [it, _] = find_closest(empty, 42);
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	CHECK(it == empty.end());
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}
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TEST_CASE("find_closest_with_time_points_and_projection")
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{
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	struct Sample {
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		int id;
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		std::chrono::steady_clock::time_point time;
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	};
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	using namespace std::chrono_literals;
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	std::array samples = {
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	        Sample{1, std::chrono::steady_clock::time_point{0ms}},
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	        Sample{2, std::chrono::steady_clock::time_point{10ms}},
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	        Sample{3, std::chrono::steady_clock::time_point{30ms}}
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	};
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	auto [it, dist] = find_closest(
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		samples, std::chrono::steady_clock::time_point{18ms}, {}, &Sample::time);
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	REQUIRE(it != samples.end());
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	CHECK(it->id == 2);
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	CHECK(dist == 8ms);
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	static_assert(std::is_same_v<decltype(dist), std::chrono::steady_clock::duration>);
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}