tests: add integration test for global_preferences

* The test container does not return the global_preferences file, so errors
* Have added some exception handling to the function in case Marshmallow validation fails

relates-to: #61

src/boinc_client/boinc_client.py

@@ -126,5 +126,8 @@ def get_client_version(self) -> dict:
     def get_client_update(self) -> dict:
         return client_update(client=self.rpc_client)
 
+    ##############
+    # Preferences
+    ##############
     def get_global_prefs_file(self) -> dict:
         return get_global_prefs_file(self.rpc_client)

src/boinc_client/preferences.py

@@ -1,11 +1,16 @@
 import xmltodict
+from marshmallow import ValidationError
 
 from boinc_client.clients.rpc_client import RpcClient
+from boinc_client.models.generic_response import GenericResponse
 from boinc_client.models.global_preferences import GlobalPreferences
 
 
 def get_global_prefs_file(client: RpcClient) -> dict:
     """Get the contents of the global_prefs.xml file if present."""
     rpc_resp = client.make_request("<get_global_prefs_file/>")
     rpc_json = xmltodict.parse(rpc_resp)
-    return GlobalPreferences().load(rpc_json)
+    try:
+        return GlobalPreferences().load(rpc_json)
+    except ValidationError:
+        return GenericResponse().load(rpc_json)

tests/integration/test_boinc_client.py

@@ -142,6 +142,13 @@ def test_container_update(boinc_session_client):
     assert "update" in result
 
 
+@mark.integration
+def test_global_preferences(boinc_session_client):
+    result = boinc_session_client.get_global_prefs_file()
+    assert result
+    assert "error" in result  # No global_preferences file available
+
+
 @mark.authenticated
 def test_can_attach_and_detach_project(boinc_test_client, project_weak_key):
     boinc_test_client.attach_project(