Fix prospector tests

* As of Python3 each class inherit from object, removing it's explicit
  inheritance. Reported by newer pylint.
* Convert if/elif/else blocks with raise or returns with if/if/raise
  or return ones. Reported by newer pylint.
* Remove explicit dependency on older vulture, as the bug in prospector
  was fixed.

Change-Id: I827657adc51148da1587578dfa15cff55ecbd351

cumin/backends/__init__.py

@@ -13,7 +13,7 @@ class InvalidQueryError(CuminError):
     """Custom exception class for invalid queries."""
 
 
-class BaseQuery(object, metaclass=ABCMeta):
+class BaseQuery(metaclass=ABCMeta):
     """Query abstract class.
 
     All backends query classes must inherit, directly or indirectly, from this one.

cumin/cli.py

@@ -41,7 +41,7 @@
 #                         -     nodes: is a ClusterShell.NodeSet.NodeSet instance
 #                         -     output: is a ClusterShell.MsgTree.MsgTreeElem instance
 #     h(): print this help message.
-#     help(object): Python default interactive help and documentation of the given object.
+#     help(object_name): Python default interactive help and documentation of the given object.
 
 = Example usage:
 for nodes, output in worker.get_results():
@@ -312,10 +312,12 @@ def get_hosts(args, config):
     if args.dry_run:
         stderr('DRY-RUN mode enabled, aborting')
         return []
-    elif args.force:
+
+    if args.force:
         stderr('FORCE mode enabled, continuing without confirmation')
         return hosts
-    elif not sys.stdout.isatty():  # pylint: disable=no-member
+
+    if not sys.stdout.isatty():  # pylint: disable=no-member
         message = 'Not in a TTY but neither DRY-RUN nor FORCE mode were specified.'
         stderr(message)
         raise cumin.CuminError(message)
@@ -393,7 +395,7 @@ def run(args, config):
     if args.interactive:
         # Define a help function h() that will be available in the interactive shell to print the help message.
         # The name is to not shadow the Python built-in help() that might be usefult too to inspect objects.
-        def h():  # pylint: disable=unused-variable,invalid-name
+        def h():  # pylint: disable=possibly-unused-variable,invalid-name
             """Print the help message in interactive shell."""
             tqdm.write(INTERACTIVE_BANNER)
         code.interact(banner=INTERACTIVE_BANNER, local=locals())

cumin/grammar.py

@@ -121,11 +121,11 @@ def _import_backend(module, available_backends):
     try:
         backend = importlib.import_module(module)
     except ImportError as e:
-        if module.startswith(INTERNAL_BACKEND_PREFIX):
-            return (None, None)  # Internal backend not available, are all the dependencies installed?
-        else:
+        if not module.startswith(INTERNAL_BACKEND_PREFIX):
             raise CuminError("Unable to import backend '{module}': {e}".format(module=module, e=e))
 
+        return (None, None)  # Internal backend not available, are all the dependencies installed?
+
     name = module.split('.')[-1]
     message = "Unable to register backend '{name}' in module '{module}'".format(name=name, module=module)
     try:

cumin/tests/integration/test_cli.py

@@ -303,7 +303,7 @@ def get_ls_expected_lines(params):
 
 
 @add_variants_methods(range(len(_VARIANTS_PARAMETERS)))
-class TestCLI(object):
+class TestCLI():
     """CLI module tests."""
 
     def setup_method(self, _):

cumin/tests/unit/backends/external/wrong_inheritance.py

@@ -1,7 +1,7 @@
 """Test external backend module with wrong inheritance of the query class."""
 
 
-class WrongInheritance(object):
+class WrongInheritance():
     """Test query class with wrong inheritance."""
 
 

cumin/tests/unit/backends/test_direct.py

@@ -10,7 +10,7 @@ def test_direct_query_class():
     assert isinstance(query, BaseQuery)
 
 
-class TestDirectQuery(object):
+class TestDirectQuery():
     """Direct backend query test class."""
 
     def setup_method(self, _):

cumin/tests/unit/backends/test_knownhosts.py

@@ -16,7 +16,7 @@ def test_knownhosts_query_class():
     assert isinstance(query, BaseQuery)
 
 
-class TestKnownhostsQuery(object):
+class TestKnownhostsQuery():
     """Knownhosts backend query test class."""
 
     def setup_method(self, _):

cumin/tests/unit/backends/test_openstack.py

@@ -47,7 +47,7 @@ def test_key_value_tokens():
 @mock.patch('cumin.backends.openstack.keystone_client.Client')
 @mock.patch('cumin.backends.openstack.keystone_session.Session')
 @mock.patch('cumin.backends.openstack.keystone_identity.Password')
-class TestOpenStackQuery(object):
+class TestOpenStackQuery():
     """OpenStack backend query test class."""
 
     def setup_method(self, _):

cumin/tests/unit/backends/test_puppetdb.py

@@ -37,7 +37,7 @@ def test_hosts_selection():
     assert parsed[0].asDict() == hosts
 
 
-class TestPuppetDBQueryV3(object):
+class TestPuppetDBQueryV3():
     """PuppetDB backend query test class for API version 3."""
 
     def setup_method(self, _):
@@ -51,7 +51,7 @@ def test_instantiation(self):
         assert self.query.url == 'https://localhost:443/v3/'
 
 
-class TestPuppetDBQueryV4(object):
+class TestPuppetDBQueryV4():
     """PuppetDB backend query test class for API version 4."""
 
     def setup_method(self, _):
@@ -102,7 +102,7 @@ def test_puppetdb_query_init_invalid():
 
 
 @mock.patch.object(puppetdb.PuppetDBQuery, '_api_call')
-class TestPuppetDBQueryBuildV3(object):
+class TestPuppetDBQueryBuildV3():
     """PuppetDB backend API v3 query build test class."""
 
     def setup_method(self, _):
@@ -155,7 +155,7 @@ def test_and_and(self, mocked_api_call):
 
 
 @mock.patch.object(puppetdb.PuppetDBQuery, '_api_call')
-class TestPuppetDBQueryBuildV4(object):
+class TestPuppetDBQueryBuildV4():
     """PuppetDB backend API v4 query build test class."""
 
     def setup_method(self, _):

cumin/tests/unit/transports/test_clustershell.py

@@ -23,7 +23,7 @@ def test_worker_class(task_self):
     task_self.assert_called_once_with()
 
 
-class TestClusterShellWorker(object):
+class TestClusterShellWorker():
     """ClusterShell backend worker test class."""
 
     @mock.patch('cumin.transports.clustershell.Task.task_self')
@@ -144,7 +144,7 @@ def test_handler_getter(self):
 
     def test_handler_setter_invalid(self):
         """Raise WorkerError if trying to set it to an invalid class or value"""
-        class InvalidClass(object):
+        class InvalidClass():
             """Invalid class."""
 
             pass
@@ -177,7 +177,7 @@ def iter_buffers():
             yield 'output {}'.format(i), ['node{}0'.format(i), 'node{}1'.format(i), 'node{}2'.format(i)]
 
 
-class TestBaseEventHandler(object):
+class TestBaseEventHandler():
     """BaseEventHandler test class."""
 
     def setup_method(self, *args):  # pylint: disable=arguments-differ

cumin/tests/unit/transports/test_init.py

@@ -32,7 +32,7 @@ def handler(self, value):
         self._handler = value
 
 
-class Commands(object):
+class Commands():
     """Helper class to define a list of commands to test."""
 
     command_with_options = r'command --with "options" -a -n -d params with\ spaces'
@@ -63,7 +63,7 @@ def __init__(self):
 
 
 @pytest.mark.parametrize('command', Commands().commands)
-class TestCommandParametrized(object):
+class TestCommandParametrized():
     """Command class tests executed for each parametrized command."""
 
     def test_instantiation(self, command):
@@ -134,7 +134,7 @@ def test_ok_codes_getter(self, command):
         assert command['obj'].ok_codes == command.get('ok_codes', [0])
 
 
-class TestCommand(object):
+class TestCommand():
     """Command class non parametrized tests."""
 
     def test_eq_equivalent(self):
@@ -197,7 +197,7 @@ def test_ok_codes_setter(self):
                 command.ok_codes = codes
 
 
-class TestState(object):
+class TestState():
     """State class tests."""
 
     def test_instantiation_no_init(self):
@@ -308,7 +308,7 @@ def test_update_ok(self):
         assert state.current == transports.State.pending
 
 
-class TestTarget(object):
+class TestTarget():
     """Target class tests."""
 
     def setup_method(self, _):
@@ -403,7 +403,7 @@ def test_first_batch(self):
         assert isinstance(target.first_batch, NodeSet)
 
 
-class TestBaseWorker(object):
+class TestBaseWorker():
     """Concrete BaseWorker class for tests."""
 
     def test_instantiation(self):
@@ -427,7 +427,7 @@ def test_init(self):
         assert worker.config == config
 
 
-class TestConcreteBaseWorker(object):
+class TestConcreteBaseWorker():
     """BaseWorker test class."""
 
     def setup_method(self, _):
@@ -501,7 +501,7 @@ def test_success_threshold_setter(self):
         assert self.worker._success_threshold == pytest.approx(0.3)
 
 
-class TestModuleFunctions(object):
+class TestModuleFunctions():
     """Transports module functions test class."""
 
     def test_validate_list(self):

cumin/transport.py

@@ -5,7 +5,7 @@
 from cumin import CuminError
 
 
-class Transport(object):
+class Transport():
     """Transport factory class.
 
     The transport layer is the one used to convey the commands to be executed into the selected hosts. The transport

cumin/transports/__init__.py

@@ -22,7 +22,7 @@ class InvalidStateError(CuminError):
     """Exception raised when an invalid transition for a node's State was attempted."""
 
 
-class Command(object):
+class Command():
     """Class to represent a command."""
 
     def __init__(self, command, timeout=None, ok_codes=None):
@@ -179,7 +179,7 @@ def ok_codes(self, value):
         self._ok_codes = value
 
 
-class State(object):
+class State():
     """State machine for the state of a host.
 
     .. attribute:: current
@@ -251,10 +251,11 @@ def __getattr__(self, name):
         """
         if name == 'current':
             return self._state
-        elif name.startswith('is_') and name[3:] in self.states_representation:
+
+        if name.startswith('is_') and name[3:] in self.states_representation:
             return getattr(self, name[3:]) == self._state
-        else:
-            raise AttributeError("'State' object has no attribute '{name}'".format(name=name))
+
+        raise AttributeError("'State' object has no attribute '{name}'".format(name=name))
 
     def __repr__(self):
         """Return the representation of the :py:class:`State`.
@@ -387,13 +388,14 @@ def _cmp(self, other):
         """
         if isinstance(other, int):
             return self._state - other
-        elif isinstance(other, State):
+
+        if isinstance(other, State):
             return self._state - other._state  # pylint: disable=protected-access
-        else:
-            raise ValueError("Unable to compare instance of '{other}' with State instance".format(other=type(other)))
+
+        raise ValueError("Unable to compare instance of '{other}' with State instance".format(other=type(other)))
 
 
-class Target(object):
+class Target():
     """Targets management class."""
 
     def __init__(self, hosts, batch_size=None, batch_size_ratio=None, batch_sleep=None):
@@ -495,7 +497,7 @@ def _compute_batch_sleep(batch_sleep):
         return batch_sleep or 0.0
 
 
-class BaseWorker(object, metaclass=ABCMeta):
+class BaseWorker(metaclass=ABCMeta):
     """Worker interface to be extended by concrete workers."""
 
     def __init__(self, config, target):

cumin/transports/clustershell.py

@@ -129,7 +129,7 @@ def handler(self, value):
                 value)
 
 
-class Node(object):
+class Node():
     """Node class to represent each target node."""
 
     def __init__(self, name, commands):

setup.py

@@ -39,7 +39,6 @@
         'sphinx_rtd_theme>=0.1.6',
         'sphinx-argparse>=0.1.15',
         'Sphinx>=1.4.9',
-        'vulture>=0.6,<0.25',  # Required for https://github.com/landscapeio/prospector/issues/230
     ],
 }