Source

`tests/purrc/socket_sys_test.cpp`

2// Original work; see ACKNOWLEDGMENTS.md for the open-source ideas we build upon.

3// System-level test for the `socket` stdlib module: ONE cohesive program that

4// exercises EVERY purr-callable function in stdlib/socket/socket.hpp end to end

5// (purrc + the C++ backend + the runtime + the linked libcheatah_socket).

6//

7// Unlike the per-function compile-run probes (socket_cr_test.cpp), this stands up

8// real loopback TCP connections on 127.0.0.1 and does full round-trips inside a

9// SINGLE cheatah process, driving both the low-level BSD path and the high-level

10// convenience helpers:

11//

12// low-level : socket -> set_reuseaddr -> bind -> listen -> local_port

13// -> (client) socket -> connect -> accept

14// -> send / recv / sendall / recv -> close

15// high-level: tcp_listen -> local_port -> tcp_connect -> accept

16// -> sendall -> recv

17// error path: connect(-1, ...) deliberately fails -> last_error() is non-empty

18//

19// All 14 exported functions are called: tcp_listen, tcp_connect, accept, recv,

20// send, sendall, close, socket, set_reuseaddr, bind, listen, connect,

21// local_port, last_error.

22//

23// Why it doesn't deadlock in one process: for 127.0.0.1 the kernel completes the

24// TCP handshake on connect() and queues the connection on the listener's accept

25// backlog, so we connect() BEFORE accept() and accept() returns immediately. The

26// payloads are tiny (fit the send buffer), so send()/sendall() never block on a

27// reader. Ports are OS-assigned (bind to port 0) so nothing depends on a fixed

28// port or external network. Output is only booleans + fixed labels, so it is

29// fully deterministic and asserted byte-for-byte. The harness runs the program

30// under `timeout` so a regression that blocks fails fast instead of hanging.

32#include "e2e_harness.hpp"

35TEST(StdlibE2E, Socket) {

36 e2e::expect_e2e("socket_sys", R"PURR(import io

37import socket

39# ---- low-level BSD path: socket/set_reuseaddr/bind/listen/local_port ----

40let srv = socket.socket()

41let reuse = socket.set_reuseaddr(srv)

42let bound = socket.bind(srv, "127.0.0.1", 0)

43let lstn = socket.listen(srv, 8)

44let port = socket.local_port(srv)

46# client socket, connect BEFORE accept (kernel queues the loopback handshake)

47let cli = socket.socket()

48let conn = socket.connect(cli, "127.0.0.1", port)

49let peer = socket.accept(srv)

51# ---- per-connection I/O: send + sendall + recv ----

52let s1 = socket.send(cli, "AB")

53let got1 = socket.recv(peer, 16)

54let s2 = socket.sendall(peer, "PONG")

55let got2 = socket.recv(cli, 16)

57# ---- high-level convenience path: tcp_listen / tcp_connect ----

58let hl_srv = socket.tcp_listen("127.0.0.1", 0, 8)

59let hl_port = socket.local_port(hl_srv)

60let hl_cli = socket.tcp_connect("127.0.0.1", hl_port)

61let hl_peer = socket.accept(hl_srv)

62let hl_s = socket.sendall(hl_cli, "hi")

63let hl_got = socket.recv(hl_peer, 16)

65# ---- deliberate failure + last_error ----

66let fail = socket.connect(-1, "127.0.0.1", 1)

67let err = socket.last_error()

69# ---- verdicts (deterministic) ----

70io.print("socket_ok", srv >= 0)

71io.print("reuse_ok", reuse == 0)

72io.print("bind_ok", bound == 0)

73io.print("listen_ok", lstn == 0)

74io.print("port_ok", port > 0)

75io.print("connect_ok", conn == 0)

76io.print("accept_ok", peer >= 0)

77io.print("send_ok", s1 == 2)

78io.print("recv1_ok", got1 == "AB")

79io.print("sendall_ok", s2 == 0)

80io.print("recv2_ok", got2 == "PONG")

81io.print("tcp_listen_ok", hl_srv >= 0)

82io.print("tcp_connect_ok", hl_cli >= 0)

83io.print("hl_roundtrip_ok", hl_got == "hi")

84io.print("fail_ok", fail < 0)

85io.print("last_error_ok", err != "")

87let c1 = socket.close(peer)

88let c2 = socket.close(cli)

89let c3 = socket.close(srv)

90socket.close(hl_peer)

91socket.close(hl_cli)

92socket.close(hl_srv)

93io.print("close_ok", c1 == 0, c2 == 0, c3 == 0)

94)PURR",

95 "socket_ok True\n"

96 "reuse_ok True\n"

97 "bind_ok True\n"

98 "listen_ok True\n"

99 "port_ok True\n"

100 "connect_ok True\n"

101 "accept_ok True\n"

102 "send_ok True\n"

103 "recv1_ok True\n"

104 "sendall_ok True\n"

105 "recv2_ok True\n"

106 "tcp_listen_ok True\n"

107 "tcp_connect_ok True\n"

108 "hl_roundtrip_ok True\n"

109 "fail_ok True\n"

110 "last_error_ok True\n"

111 "close_ok True True True\n");

112}