remove dead code, add pidfile tests

test/test_pidfile.py

@@ -0,0 +1,24 @@
+from pathlib import Path
+from unittest.mock import MagicMock
+
+import pytest
+
+from croaker import pidfile
+
+
+@pytest.mark.parametrize('pid,terminate,kill_result,broken', [
+    ('pid', False, None, False),               # running proc, no terminate
+    ('pid', True, True, False),                # running proc, terminate
+    ('pid', True, ProcessLookupError, True),   # stale pid
+    (None, None, None, False),                  # no running proc
+])
+def test_pidfile(monkeypatch, pid, terminate, kill_result, broken):
+    monkeypatch.setattr(pidfile._pidfile, 'TimeoutPIDLockFile', MagicMock(**{
+        'return_value.read_pid.return_value': pid,
+    }))
+    monkeypatch.setattr(pidfile.os, 'kill', MagicMock(**{
+        'side_effect': kill_result if type(kill_result) is Exception else [kill_result]
+    }))
+
+    ret = pidfile.pidfile(pidfile_path=Path('/dev/null'), terminate_if_running=terminate)
+    assert ret.break_lock.called == broken