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#include "testUtils.hpp"
#include <cstdint>
#include <stdexcept>
#ifdef _WIN32
#define NOMINMAX
#include <winsock2.h>
#include <ws2tcpip.h>
#else
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#endif
namespace cpr::test {
std::uint16_t get_free_port() {
#ifdef _WIN32
static const WSAInit wsa_guard; // one-time Winsock init
#endif
// 1. Create a TCP socket.
socket_t sock = ::socket(AF_INET, SOCK_STREAM, 0);
if (sock == INVALID_SOCKET_FD) {
throw std::runtime_error("socket() failed");
}
// 2. Bind to port 0 so the OS assigns an ephemeral port.
sockaddr_in addr{};
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(0); // 0 ⇒ “pick for me”
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
if (::bind(sock, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) != 0) {
#ifdef _WIN32
::closesocket(sock);
#else
::close(sock);
#endif
throw std::runtime_error("bind() failed");
}
// 3. Ask what port we actually got.
socklen_t len = sizeof(addr);
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
if (::getsockname(sock, reinterpret_cast<sockaddr*>(&addr), &len) != 0) {
#ifdef _WIN32
::closesocket(sock);
#else
::close(sock);
#endif
throw std::runtime_error("getsockname() failed");
}
std::uint16_t port = ntohs(addr.sin_port);
// 4. Close the socket ‒ we only needed it to grab the port number.
#ifdef _WIN32
::closesocket(sock);
#else
::close(sock);
#endif
return port;
}
} // namespace cpr::test
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