test: sock: Enable socket pair tests on Windows

diff --git a/src/test/sock_tests.cpp b/src/test/sock_tests.cpp
index 06d9f7d3..56fdfaaf 100644
--- a/src/test/sock_tests.cpp
+++ b/src/test/sock_tests.cpp
@@ -81,61 +81,75 @@ BOOST_AUTO_TEST_CASE(move_assignment)
     BOOST_CHECK(SocketIsClosed(s2));
 }
 
-#ifndef WIN32 // Windows does not have socketpair(2).
-
-static void CreateSocketPair(int s[2])
-{
-    BOOST_REQUIRE_EQUAL(socketpair(AF_UNIX, SOCK_STREAM, 0, s), 0);
-}
-
-static void SendAndRecvMessage(const Sock& sender, const Sock& receiver)
-{
-    const char* msg = "abcd";
-    constexpr ssize_t msg_len = 4;
-    char recv_buf[10];
-
-    BOOST_CHECK_EQUAL(sender.Send(msg, msg_len, 0), msg_len);
-    BOOST_CHECK_EQUAL(receiver.Recv(recv_buf, sizeof(recv_buf), 0), msg_len);
-    BOOST_CHECK_EQUAL(strncmp(msg, recv_buf, msg_len), 0);
-}
+struct TcpSocketPair {
+    Sock sender;
+    Sock receiver;
+
+    TcpSocketPair()
+        : sender{Sock{CreateSocket()}},
+        receiver{Sock{CreateSocket()}}
+    {
+        connect_pair();
+    }
+
+    TcpSocketPair(const TcpSocketPair&) = delete;
+    TcpSocketPair& operator= (const TcpSocketPair&) = delete;
+    TcpSocketPair(TcpSocketPair&&) = default;
+    TcpSocketPair& operator= (TcpSocketPair&&) = default;
+
+    void connect_pair()
+    {
+        sockaddr_in addr{};
+        addr.sin_family = AF_INET;
+        addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+        addr.sin_port = 0;
+
+        BOOST_REQUIRE_EQUAL(receiver.Bind(reinterpret_cast<sockaddr*>(&addr), sizeof(addr)), 0);
+        BOOST_REQUIRE_EQUAL(receiver.Listen(1), 0);
+
+        // Get the address of the listener.
+        sockaddr_in bound{};
+        socklen_t blen = sizeof(bound);
+        BOOST_REQUIRE_EQUAL(receiver.GetSockName(reinterpret_cast<sockaddr*>(&bound), &blen), 0);
+        BOOST_REQUIRE_EQUAL(blen, sizeof(bound));
+
+        BOOST_REQUIRE_EQUAL(sender.Connect(reinterpret_cast<sockaddr*>(&bound), sizeof(bound)), 0);
+
+        std::unique_ptr<Sock> accepted = receiver.Accept(nullptr, nullptr);
+        BOOST_REQUIRE(accepted != nullptr);
+
+        receiver = std::move(*accepted);
+    }
+
+    void send_and_receive()
+    {
+        const char* msg = "abcd";
+        constexpr ssize_t msg_len = 4;
+        char recv_buf[10];
+
+        BOOST_CHECK_EQUAL(sender.Send(msg, msg_len, 0), msg_len);
+        BOOST_CHECK_EQUAL(receiver.Recv(recv_buf, sizeof(recv_buf), 0), msg_len);
+        BOOST_CHECK_EQUAL(strncmp(msg, recv_buf, msg_len), 0);
+    }
+};
 
 BOOST_AUTO_TEST_CASE(send_and_receive)
 {
-    int s[2];
-    CreateSocketPair(s);
-
-    Sock* sock0 = new Sock(s[0]);
-    Sock* sock1 = new Sock(s[1]);
+    TcpSocketPair socks{};
+    socks.send_and_receive();
 
-    SendAndRecvMessage(*sock0, *sock1);
-
-    Sock* sock0moved = new Sock(std::move(*sock0));
-    Sock* sock1moved = new Sock(INVALID_SOCKET);
-    *sock1moved = std::move(*sock1);
-
-    delete sock0;
-    delete sock1;
-
-    SendAndRecvMessage(*sock1moved, *sock0moved);
-
-    delete sock0moved;
-    delete sock1moved;
-
-    BOOST_CHECK(SocketIsClosed(s[0]));
-    BOOST_CHECK(SocketIsClosed(s[1]));
+    // Sockets are still connected after being moved.
+    TcpSocketPair socks_moved = std::move(socks);
+    socks_moved.send_and_receive();
 }
 
 BOOST_AUTO_TEST_CASE(wait)
 {
-    int s[2];
-    CreateSocketPair(s);
+    TcpSocketPair socks = TcpSocketPair{};
 
-    Sock sock0(s[0]);
-    Sock sock1(s[1]);
+    std::thread waiter([&socks]() { (void)socks.receiver.Wait(24h, Sock::RECV); });
 
-    std::thread waiter([&sock0]() { (void)sock0.Wait(24h, Sock::RECV); });
-
-    BOOST_REQUIRE_EQUAL(sock1.Send("a", 1, 0), 1);
+    BOOST_REQUIRE_EQUAL(socks.sender.Send("a", 1, 0), 1);
 
     waiter.join();
 }
@@ -144,31 +158,26 @@ BOOST_AUTO_TEST_CASE(recv_until_terminator_limit)
 {
     constexpr auto timeout = 1min; // High enough so that it is never hit.
     CThreadInterrupt interrupt;
-    int s[2];
-    CreateSocketPair(s);
 
-    Sock sock_send(s[0]);
-    Sock sock_recv(s[1]);
+    TcpSocketPair socks = TcpSocketPair{};
 
-    std::thread receiver([&sock_recv, &timeout, &interrupt]() {
+    std::thread receiver([&socks, &timeout, &interrupt]() {
         constexpr size_t max_data{10};
         bool threw_as_expected{false};
         // BOOST_CHECK_EXCEPTION() writes to some variables shared with the main thread which
         // creates a data race. So mimic it manually.
         try {
-            (void)sock_recv.RecvUntilTerminator('\n', timeout, interrupt, max_data);
+            (void)socks.receiver.RecvUntilTerminator('\n', timeout, interrupt, max_data);
         } catch (const std::runtime_error& e) {
             threw_as_expected = HasReason("too many bytes without a terminator")(e);
         }
         assert(threw_as_expected);
     });
 
-    BOOST_REQUIRE_NO_THROW(sock_send.SendComplete("1234567", timeout, interrupt));
-    BOOST_REQUIRE_NO_THROW(sock_send.SendComplete("89a\n", timeout, interrupt));
+    BOOST_REQUIRE_NO_THROW(socks.sender.SendComplete("1234567", timeout, interrupt));
+    BOOST_REQUIRE_NO_THROW(socks.sender.SendComplete("89a\n", timeout, interrupt));
 
     receiver.join();
 }
 
-#endif /* WIN32 */
-
 BOOST_AUTO_TEST_SUITE_END()