merge: testing → main (reconcile 2-week divergence)

tests/web/services/test_systemd_control.py

@@ -0,0 +1,133 @@
+"""Unit tests for :mod:`decnet.web.services.systemd_control`.
+
+These tests monkeypatch :func:`asyncio.create_subprocess_exec` so we
+never touch real ``systemctl``.  The contract under test is:
+
+* argv shape — ``["systemctl", <verb>, "decnet-<name>.service"]``
+* non-zero return ⇒ :class:`SystemctlError` with returncode + stderr
+* ``list_installed`` parses ``list-unit-files`` output into a name set
+* cache honours the 30s TTL
+"""
+from __future__ import annotations
+
+import asyncio
+from typing import Any, List, Tuple
+
+import pytest
+
+from decnet.web.services import systemd_control as sc
+
+
+class _FakeProc:
+    def __init__(self, returncode: int, stdout: bytes, stderr: bytes) -> None:
+        self.returncode = returncode
+        self._stdout = stdout
+        self._stderr = stderr
+
+    async def communicate(self) -> Tuple[bytes, bytes]:
+        return self._stdout, self._stderr
+
+
+def _patch_exec(monkeypatch: Any, *, rc: int = 0, stdout: bytes = b"", stderr: bytes = b"") -> List[tuple]:
+    calls: List[tuple] = []
+
+    async def fake_exec(*argv: str, **_kwargs: Any) -> _FakeProc:
+        calls.append(argv)
+        return _FakeProc(rc, stdout, stderr)
+
+    monkeypatch.setattr(asyncio, "create_subprocess_exec", fake_exec)
+    return calls
+
+
+@pytest.fixture(autouse=True)
+def _reset_cache() -> None:
+    sc.reset_cache_for_tests()
+    yield
+    sc.reset_cache_for_tests()
+
+
+@pytest.mark.asyncio
+async def test_start_builds_correct_argv(monkeypatch: Any) -> None:
+    calls = _patch_exec(monkeypatch, rc=0)
+    await sc.start("mutator")
+    assert calls == [("systemctl", "start", "decnet-mutator.service")]
+
+
+@pytest.mark.asyncio
+async def test_stop_builds_correct_argv(monkeypatch: Any) -> None:
+    calls = _patch_exec(monkeypatch, rc=0)
+    await sc.stop("sniffer")
+    assert calls == [("systemctl", "stop", "decnet-sniffer.service")]
+
+
+@pytest.mark.asyncio
+async def test_start_raises_systemctl_error_on_nonzero(monkeypatch: Any) -> None:
+    _patch_exec(monkeypatch, rc=5, stderr=b"Unit decnet-mutator.service not found.\n")
+    with pytest.raises(sc.SystemctlError) as exc_info:
+        await sc.start("mutator")
+    err = exc_info.value
+    assert err.returncode == 5
+    assert err.unit == "decnet-mutator.service"
+    assert "not found" in err.stderr
+
+
+@pytest.mark.asyncio
+async def test_is_active_true_when_stdout_active(monkeypatch: Any) -> None:
+    _patch_exec(monkeypatch, rc=0, stdout=b"active\n")
+    assert await sc.is_active("bus") is True
+
+
+@pytest.mark.asyncio
+async def test_is_active_false_when_inactive(monkeypatch: Any) -> None:
+    # systemctl exits 3 for "inactive" — is_active must treat that as a
+    # signal, not an error.
+    _patch_exec(monkeypatch, rc=3, stdout=b"inactive\n")
+    assert await sc.is_active("bus") is False
+
+
+@pytest.mark.asyncio
+async def test_list_installed_parses_unit_files(monkeypatch: Any) -> None:
+    stdout = (
+        b"decnet-bus.service         enabled         enabled\n"
+        b"decnet-api.service         enabled         enabled\n"
+        b"decnet-mutator.service     disabled        enabled\n"
+    )
+    _patch_exec(monkeypatch, rc=0, stdout=stdout)
+    names = await sc.list_installed()
+    assert names == {"bus", "api", "mutator"}
+
+
+@pytest.mark.asyncio
+async def test_list_installed_returns_empty_on_failure(monkeypatch: Any) -> None:
+    _patch_exec(monkeypatch, rc=1, stderr=b"systemctl: command not found\n")
+    names = await sc.list_installed()
+    assert names == set()
+
+
+@pytest.mark.asyncio
+async def test_list_installed_is_cached(monkeypatch: Any) -> None:
+    stdout = b"decnet-bus.service enabled enabled\n"
+    calls = _patch_exec(monkeypatch, rc=0, stdout=stdout)
+    await sc.list_installed()
+    await sc.list_installed()
+    await sc.list_installed()
+    # Three logical calls, one real subprocess invocation.
+    assert len(calls) == 1
+
+
+@pytest.mark.asyncio
+async def test_list_installed_force_bypasses_cache(monkeypatch: Any) -> None:
+    stdout = b"decnet-bus.service enabled enabled\n"
+    calls = _patch_exec(monkeypatch, rc=0, stdout=stdout)
+    await sc.list_installed()
+    await sc.list_installed(force=True)
+    assert len(calls) == 2
+
+
+def test_invalid_worker_name_rejected() -> None:
+    with pytest.raises(ValueError):
+        sc._unit("../etc/passwd")
+    with pytest.raises(ValueError):
+        sc._unit("bus.service")
+    with pytest.raises(ValueError):
+        sc._unit("")