chore: add test for credentials parsing

Author: kangasta

requirements-dev.in

@@ -1,5 +1,6 @@
+keyring
 mock
 pip-tools
 pytest
 pytest-cov
-responses
+responses

requirements-dev.txt

@@ -18,8 +18,20 @@ idna==3.10
     # via requests
 iniconfig==2.1.0
     # via pytest
+jaraco-classes==3.4.0
+    # via keyring
+jaraco-context==6.0.1
+    # via keyring
+jaraco-functools==4.2.1
+    # via keyring
+keyring==25.6.0
+    # via -r requirements-dev.in
 mock==5.2.0
     # via -r requirements-dev.in
+more-itertools==10.7.0
+    # via
+    #   jaraco-classes
+    #   jaraco-functools
 packaging==25.0
     # via
     #   build

test/test_cloud_manager.py

@@ -1,10 +1,18 @@
 import json
 
+import pytest
 import responses
+
 from conftest import Mock
+from upcloud_api import CloudManager
+from upcloud_api.errors import UpCloudClientError
 
 
 class TestCloudManagerBasic:
+    def test_no_credentials(self):
+        with pytest.raises(UpCloudClientError):
+            CloudManager()
+
     @responses.activate
     def test_get_account(self, manager):
         data = Mock.mock_get("account")