From 81d02bb218cb730bd6b7a99597400744ae26055a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sun, 27 Aug 2023 09:34:36 +0200
Subject: [PATCH 1/2] tests: rewrite port allocation function

---
 pkgs/clan-cli/tests/ports.py      | 73 +++++++++++++++++--------------
 pkgs/clan-cli/tests/sshd.py       | 11 +++--
 pkgs/clan-cli/tests/test_webui.py |  6 +--
 3 files changed, 52 insertions(+), 38 deletions(-)

diff --git a/pkgs/clan-cli/tests/ports.py b/pkgs/clan-cli/tests/ports.py
index dba5f50ed..6d129c5ab 100644
--- a/pkgs/clan-cli/tests/ports.py
+++ b/pkgs/clan-cli/tests/ports.py
@@ -1,46 +1,55 @@
 #!/usr/bin/env python3
 
+import contextlib
 import socket
+from typing import Callable
 
 import pytest
 
-NEXT_PORT = 10000
+
+def _unused_port(socket_type: int) -> int:
+    """Find an unused localhost port from 1024-65535 and return it."""
+    with contextlib.closing(socket.socket(type=socket_type)) as sock:
+        sock.bind(("127.0.0.1", 0))
+        return sock.getsockname()[1]
 
 
-def check_port(port: int) -> bool:
-    tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-    udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-    with tcp, udp:
-        try:
-            tcp.bind(("127.0.0.1", port))
-            udp.bind(("127.0.0.1", port))
-            return True
-        except socket.error:
-            return False
+PortFunction = Callable[[], int]
 
 
-def check_port_range(port_range: range) -> bool:
-    for port in port_range:
-        if not check_port(port):
-            return False
-    return True
+@pytest.fixture(scope="session")
+def unused_tcp_port() -> PortFunction:
+    """A function, producing different unused TCP ports."""
+    produced = set()
+
+    def factory() -> int:
+        """Return an unused port."""
+        port = _unused_port(socket.SOCK_STREAM)
+
+        while port in produced:
+            port = _unused_port(socket.SOCK_STREAM)
+
+        produced.add(port)
+
+        return port
+
+    return factory
 
 
-class Ports:
-    def allocate(self, num: int) -> int:
-        """
-        Allocates
-        """
-        global NEXT_PORT
-        while NEXT_PORT + num <= 65535:
-            start = NEXT_PORT
-            NEXT_PORT += num
-            if not check_port_range(range(start, NEXT_PORT)):
-                continue
-            return start
-        raise Exception("cannot find enough free port")
+@pytest.fixture(scope="session")
+def unused_udp_port() -> PortFunction:
+    """A function, producing different unused UDP ports."""
+    produced = set()
 
+    def factory() -> int:
+        """Return an unused port."""
+        port = _unused_port(socket.SOCK_DGRAM)
 
-@pytest.fixture
-def ports() -> Ports:
-    return Ports()
+        while port in produced:
+            port = _unused_port(socket.SOCK_DGRAM)
+
+        produced.add(port)
+
+        return port
+
+    return factory
diff --git a/pkgs/clan-cli/tests/sshd.py b/pkgs/clan-cli/tests/sshd.py
index 19f30951e..b30131738 100644
--- a/pkgs/clan-cli/tests/sshd.py
+++ b/pkgs/clan-cli/tests/sshd.py
@@ -11,7 +11,7 @@ import pytest
 
 if TYPE_CHECKING:
     from command import Command
-    from ports import Ports
+    from ports import PortFunction
 
 
 class Sshd:
@@ -104,8 +104,13 @@ exec {bash} -l "${{@}}"
 
 
 @pytest.fixture
-def sshd(sshd_config: SshdConfig, command: "Command", ports: "Ports") -> Iterator[Sshd]:
-    port = ports.allocate(1)
+def sshd(
+    sshd_config: SshdConfig, command: "Command", unused_tcp_port: "PortFunction"
+) -> Iterator[Sshd]:
+    import subprocess
+
+    subprocess.run(["echo", "hello"], check=True)
+    port = unused_tcp_port()
     sshd = shutil.which("sshd")
     assert sshd is not None, "no sshd binary found"
     env = {}
diff --git a/pkgs/clan-cli/tests/test_webui.py b/pkgs/clan-cli/tests/test_webui.py
index 1cf19aaa2..9c43a6719 100644
--- a/pkgs/clan-cli/tests/test_webui.py
+++ b/pkgs/clan-cli/tests/test_webui.py
@@ -5,11 +5,11 @@ import subprocess
 import sys
 from pathlib import Path
 
-from ports import Ports
+from ports import PortFunction
 
 
-def test_start_server(ports: Ports, temporary_dir: Path) -> None:
-    port = ports.allocate(1)
+def test_start_server(unused_tcp_port: PortFunction, temporary_dir: Path) -> None:
+    port = unused_tcp_port()
 
     fifo = temporary_dir / "fifo"
     os.mkfifo(fifo)

From 9cc6a14d730ef38805a85d0e1fd79f77ab5c75af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sun, 27 Aug 2023 09:45:15 +0200
Subject: [PATCH 2/2] run pytest in parallel

---
 pkgs/clan-cli/default.nix    | 2 ++
 pkgs/clan-cli/pyproject.toml | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/clan-cli/default.nix b/pkgs/clan-cli/default.nix
index feee2d824..b1bde572b 100644
--- a/pkgs/clan-cli/default.nix
+++ b/pkgs/clan-cli/default.nix
@@ -9,6 +9,7 @@
 , pytest
 , pytest-cov
 , pytest-subprocess
+, pytest-parallel
 , python3
 , runCommand
 , self
@@ -36,6 +37,7 @@ let
     pytest
     pytest-cov
     pytest-subprocess
+    pytest-parallel
     openssh
     stdenv.cc
   ];
diff --git a/pkgs/clan-cli/pyproject.toml b/pkgs/clan-cli/pyproject.toml
index 1892ad69d..fcaad7d79 100644
--- a/pkgs/clan-cli/pyproject.toml
+++ b/pkgs/clan-cli/pyproject.toml
@@ -15,7 +15,7 @@ exclude = ["clan_cli.nixpkgs*"]
 clan_cli = [ "config/jsonschema/*", "webui/assets/**/*"]
 
 [tool.pytest.ini_options]
-addopts = "--cov . --cov-report term --cov-report html:.reports/html --no-cov-on-fail"
+addopts = "--cov . --cov-report term --cov-report html:.reports/html --no-cov-on-fail --workers auto"
 norecursedirs = "tests/helpers"
 
 [tool.mypy]