feat: add daemon module with cross-platform process lifecycle

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/test_daemon.py

@@ -0,0 +1,96 @@
+import os
+import tempfile
+import pytest
+from unittest.mock import patch, MagicMock
+from jianda_proxy.daemon import (
+    read_pid,
+    write_pid,
+    remove_pid,
+    is_process_alive,
+    is_running,
+    stop_daemon,
+    get_status,
+)
+
+
+class TestPidFile:
+    def test_write_and_read_pid(self, tmp_path, monkeypatch):
+        pid_file = str(tmp_path / "test.pid")
+        monkeypatch.setattr("jianda_proxy.daemon.get_pid_path", lambda: pid_file)
+        write_pid(12345)
+        assert read_pid() == 12345
+
+    def test_read_missing_pid_returns_none(self, tmp_path, monkeypatch):
+        pid_file = str(tmp_path / "nonexistent.pid")
+        monkeypatch.setattr("jianda_proxy.daemon.get_pid_path", lambda: pid_file)
+        assert read_pid() is None
+
+    def test_remove_pid(self, tmp_path, monkeypatch):
+        pid_file = str(tmp_path / "test.pid")
+        monkeypatch.setattr("jianda_proxy.daemon.get_pid_path", lambda: pid_file)
+        write_pid(12345)
+        remove_pid()
+        assert read_pid() is None
+
+
+class TestProcessCheck:
+    @patch("os.kill")
+    def test_alive_on_unix(self, mock_kill):
+        mock_kill.return_value = None
+        assert is_process_alive(12345) is True
+
+    @patch("os.kill", side_effect=ProcessLookupError)
+    def test_dead_on_unix(self, mock_kill):
+        assert is_process_alive(12345) is False
+
+    @patch("os.kill", side_effect=PermissionError)
+    def test_permission_means_alive(self, mock_kill):
+        assert is_process_alive(12345) is True
+
+
+class TestIsRunning:
+    @patch("jianda_proxy.daemon.is_process_alive", return_value=True)
+    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
+    def test_running_when_pid_and_alive(self, mock_read, mock_alive):
+        assert is_running() is True
+
+    @patch("jianda_proxy.daemon.is_process_alive", return_value=False)
+    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
+    def test_not_running_when_pid_dead(self, mock_read, mock_alive):
+        assert is_running() is False
+
+    @patch("jianda_proxy.daemon.read_pid", return_value=None)
+    def test_not_running_when_no_pid(self, mock_read):
+        assert is_running() is False
+
+
+class TestStopDaemon:
+    @patch("jianda_proxy.daemon.is_process_alive", return_value=True)
+    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
+    @patch("time.sleep")
+    @patch("os.kill")
+    def test_stop_sends_sigterm(self, mock_kill, mock_sleep, mock_read, mock_alive):
+        mock_alive.side_effect = [True, False]
+        stop_daemon()
+        mock_kill.assert_called_once_with(12345, 15)  # SIGTERM=15
+
+    @patch("jianda_proxy.daemon.remove_pid")
+    @patch("jianda_proxy.daemon.is_process_alive", return_value=False)
+    @patch("jianda_proxy.daemon.read_pid", return_value=None)
+    def test_stop_noop_when_not_running(self, mock_read, mock_alive, mock_remove):
+        result = stop_daemon()
+        assert result == "not_running"
+
+
+class TestGetStatus:
+    @patch("jianda_proxy.daemon.is_process_alive", return_value=True)
+    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
+    def test_status_running(self, mock_read, mock_alive):
+        status = get_status()
+        assert status["running"] is True
+        assert status["pid"] == 12345
+
+    @patch("jianda_proxy.daemon.read_pid", return_value=None)
+    def test_status_not_running(self, mock_read):
+        status = get_status()
+        assert status["running"] is False