Fix command line options machinery

... by refactoring essential pytest fixtures to the main package. They
have been added to `testing` beforehand, which is just plain wrong, and
broke the 0.4.0 release.

CHANGES.rst

@@ -5,6 +5,9 @@ pytest-mqtt changelog
 
 in progress
 ===========
+- Fix command line options machinery by refactoring essential
+  pytest fixtures to the main package. They have been added to ``testing``
+  beforehand, which is just plain wrong, and broke the 0.4.0 release.
 
 2024-03-31 0.4.0
 ================

pytest_mqtt/mosquitto.py

@@ -80,6 +80,19 @@ def is_mosquitto_running(host: str, port: int) -> bool:
     return probe_tcp_connect(host, port)
 
 
+def pytest_addoption(parser) -> None:
+    parser.addoption("--mqtt-host", action="store", type=str, default="localhost", help="MQTT host name")
+    parser.addoption("--mqtt-port", action="store", type=int, default=1883, help="MQTT port number")
+
+
+@pytest.fixture(scope="session")
+def mqtt_settings(pytestconfig) -> MqttSettings:
+    return MqttSettings(
+        host=pytestconfig.getoption("--mqtt-host"),
+        port=pytestconfig.getoption("--mqtt-port"),
+    )
+
+
 @pytest.fixture(scope="session")
 def mosquitto(mqtt_settings: MqttSettings):