chore: improve keyring maintenance path

keyring/backend.py

@@ -12,6 +12,7 @@
 import os
 import typing
 import warnings
+from collections.abc import Callable
 
 from jaraco.context import ExceptionTrap
 from jaraco.functools import once
@@ -23,8 +24,8 @@
 log = logging.getLogger(__name__)
 
 
-by_priority = operator.attrgetter('priority')
-_limit: typing.Callable[[KeyringBackend], bool] | None = None
+by_priority: Callable[[KeyringBackend | type[KeyringBackend]], float] = operator.attrgetter('priority')
+_limit: Callable[[KeyringBackend], bool] | None = None
 
 
 class KeyringBackendMeta(abc.ABCMeta):

tests/test_cli.py

@@ -94,3 +94,27 @@ def test_get(monkeypatch, mocked_get_credential, format, capsys):
     tool.output_format = format
     tool.do_get()
     assert 's3cret' in capsys.readouterr().out
+
+
+def test_set_missing_service():
+    tool = cli.CommandLineTool()
+    with pytest.raises(SystemExit):
+        tool.run(['set'])
+
+
+def test_set_missing_username():
+    tool = cli.CommandLineTool()
+    with pytest.raises(SystemExit):
+        tool.run(['set', 'svc'])
+
+
+def test_get_password_missing_username():
+    tool = cli.CommandLineTool()
+    with pytest.raises(SystemExit):
+        tool.run(['get', 'svc'])
+
+
+def test_invalid_backend():
+    tool = cli.CommandLineTool()
+    with pytest.raises(SystemExit):
+        tool.run(['-b', 'nonexistent.backend', 'get', 'svc', 'usr'])