Add service to scan for new Plex clients (#39074)

tests/components/plex/test_services.py

@@ -5,6 +5,7 @@ from homeassistant.components.plex.const import (
     DOMAIN,
     PLEX_SERVER_CONFIG,
     SERVICE_REFRESH_LIBRARY,
+    SERVICE_SCAN_CLIENTS,
 )
 from homeassistant.const import (
     CONF_HOST,
@@ -100,3 +101,28 @@ async def test_refresh_library(hass):
             True,
         )
         assert not mock_update.called
+
+
+async def test_scan_clients(hass):
+    """Test scan_for_clients service call."""
+    entry = MockConfigEntry(
+        domain=DOMAIN,
+        data=DEFAULT_DATA,
+        options=DEFAULT_OPTIONS,
+        unique_id=DEFAULT_DATA["server_id"],
+    )
+
+    mock_plex_server = MockPlexServer(config_entry=entry)
+
+    with patch("plexapi.server.PlexServer", return_value=mock_plex_server), patch(
+        "plexapi.myplex.MyPlexAccount", return_value=MockPlexAccount()
+    ), patch("homeassistant.components.plex.PlexWebsocket", autospec=True):
+        entry.add_to_hass(hass)
+        assert await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
+
+    assert await hass.services.async_call(
+        DOMAIN,
+        SERVICE_SCAN_CLIENTS,
+        blocking=True,
+    )