light/modules/time/private/timer.test.cpp
2025-07-25 15:07:13 +03:30

70 lines
1.9 KiB
C++

#include <ranges>
#include <test/test.hpp>
#include <time/timer.hpp>
namespace lt {
using lt::test::expect_le;
// error margin is high since run-time may slow down extremely due to
// sanitization/debugging or execution through valgrind...
//
// <1us error margin is tested manually in release builds and it works fine.
constexpr auto max_error_margin = std::chrono::milliseconds { 1 };
lt::test::Suite raii = [] {
using std::chrono::microseconds;
lt::test::Case { "default" } = [] {
Timer {};
};
lt::test::Case { "unhappy path throws" } = [] {
};
lt::test::Case { "plenty" } = [] {
for (auto idx : std::views::iota(0, 100'001))
{
Timer {};
}
};
};
lt::test::Suite reset_and_elapsed_time = [] {
using std::chrono::hours;
using std::chrono::microseconds;
lt::test::Case { "won't throw" } = [] {
Timer {}.reset();
std::ignore = Timer {}.elapsed_time();
};
lt::test::Case { "elapsed time is sane" } = [] {
expect_le(Timer {}.elapsed_time(), max_error_margin);
};
lt::test::Case { "elapsed time is sane - constructed with old now" } = [] {
const auto timepoint = Timer::Clock::now() - hours { 1 };
// This fails sometimes in debug if error-range is under 10us
expect_le(Timer { timepoint }.elapsed_time(), hours { 1 } + max_error_margin);
};
lt::test::Case { "reset -> elapsed time is sane - constructed with old now" } = [] {
auto timer = Timer { Timer::Clock::now() - microseconds { 100 } };
const auto old_elapsed_time = timer.elapsed_time();
timer.reset();
expect_le(timer.elapsed_time() - old_elapsed_time, microseconds { 100 } + max_error_margin);
};
lt::test::Case { "reset -> elapsed time is sane - reset with future now" } = [] {
auto timer = Timer {};
const auto old_elapsed_time = timer.elapsed_time();
timer.reset(Timer::Clock::now() + microseconds { 100 });
expect_le(timer.elapsed_time() - old_elapsed_time, microseconds { 100 } + max_error_margin);
};
};
} // namespace lt