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

tests/bus/test_factory.py

@@ -0,0 +1,52 @@
+"""Tests for :func:`decnet.bus.factory.get_bus` dispatch."""
+from __future__ import annotations
+
+import pathlib
+
+import pytest
+
+from decnet.bus.factory import _default_socket_path, get_bus
+from decnet.bus.fake import FakeBus, NullBus
+from decnet.bus.unix_client import UnixSocketBus
+
+
+def test_disabled_returns_null_bus(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("DECNET_BUS_ENABLED", "false")
+    monkeypatch.setenv("DECNET_BUS_TYPE", "unix")  # ignored when disabled
+    bus = get_bus()
+    assert isinstance(bus, NullBus)
+
+
+def test_fake_dispatch(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("DECNET_BUS_ENABLED", "true")
+    monkeypatch.setenv("DECNET_BUS_TYPE", "fake")
+    bus = get_bus()
+    assert isinstance(bus, FakeBus)
+
+
+def test_unix_dispatch(monkeypatch: pytest.MonkeyPatch, tmp_path: pathlib.Path) -> None:
+    monkeypatch.setenv("DECNET_BUS_ENABLED", "true")
+    monkeypatch.setenv("DECNET_BUS_TYPE", "unix")
+    monkeypatch.setenv("DECNET_BUS_SOCKET", str(tmp_path / "b.sock"))
+    bus = get_bus()
+    assert isinstance(bus, UnixSocketBus)
+
+
+def test_unknown_type_raises(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("DECNET_BUS_ENABLED", "true")
+    monkeypatch.setenv("DECNET_BUS_TYPE", "mqtt")
+    with pytest.raises(ValueError, match="Unsupported bus type"):
+        get_bus()
+
+
+def test_default_socket_path_honors_env(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("DECNET_BUS_SOCKET", "/tmp/explicit.sock")
+    assert _default_socket_path() == "/tmp/explicit.sock"
+
+
+def test_default_socket_path_falls_back_to_home(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("DECNET_BUS_SOCKET", raising=False)
+    # Force /run/decnet to look unusable.
+    monkeypatch.setattr("os.path.isdir", lambda p: False)
+    path = _default_socket_path()
+    assert path.endswith(".decnet/bus.sock")