Enable linter

.github/workflows/python-package.yml

@@ -60,7 +60,7 @@ jobs:
     - name: Lint
       if: ${{ matrix.lint == 'true' }}
       run: |
-        #pylint msal_extensions
+        pylint msal_extensions
         # stop the build if there are Python syntax errors or undefined names
         #flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide

.pylintrc

@@ -2,5 +2,7 @@
 good-names=
     logger
 disable=
+    super-with-arguments,  # For Python 2.x
+    raise-missing-from,  # For Python 2.x
     trailing-newlines,
     useless-object-inheritance

msal_extensions/cache_lock.py

@@ -4,11 +4,13 @@
 import errno
 import time
 import logging
-
-logger = logging.getLogger(__name__)
+from distutils.version import LooseVersion
+import warnings
 
 import portalocker
-from distutils.version import LooseVersion
+
+
+logger = logging.getLogger(__name__)
 
 
 class CrossPlatLock(object):
@@ -19,7 +21,8 @@ class CrossPlatLock(object):
     def __init__(self, lockfile_path):
         self._lockpath = lockfile_path
         # Support for passing through arguments to the open syscall was added in v1.4.0
-        open_kwargs = {'buffering': 0} if LooseVersion(portalocker.__version__) >= LooseVersion("1.4.0") else {}
+        open_kwargs = ({'buffering': 0}
+            if LooseVersion(portalocker.__version__) >= LooseVersion("1.4.0") else {})
         self._lock = portalocker.Lock(
             lockfile_path,
             mode='wb+',
@@ -31,6 +34,11 @@ def __init__(self, lockfile_path):
             **open_kwargs)
 
     def try_to_create_lock_file(self):
+        """Do not call this. It will be removed in next release"""
+        warnings.warn("try_to_create_lock_file() will be removed", DeprecationWarning)
+        return self._try_to_create_lock_file()
+
+    def _try_to_create_lock_file(self):
         timeout = 5
         check_interval = 0.25
         current_time = getattr(time, "monotonic", time.time)
@@ -48,7 +56,7 @@ def try_to_create_lock_file(self):
         return False
 
     def __enter__(self):
-        if not self.try_to_create_lock_file():
+        if not self._try_to_create_lock_file():
             logger.warning("Failed to create lock file")
         file_handle = self._lock.__enter__()
         file_handle.write('{} {}'.format(os.getpid(), sys.argv[0]).encode('utf-8'))

msal_extensions/libsecret.py

@@ -18,7 +18,7 @@
 logger = logging.getLogger(__name__)
 
 try:
-    import gi  # https://github.com/AzureAD/microsoft-authentication-extensions-for-python/wiki/Encryption-on-Linux
+    import gi  # https://github.com/AzureAD/microsoft-authentication-extensions-for-python/wiki/Encryption-on-Linux  # pylint: disable=line-too-long
 except ImportError:
     logger.exception(
         """Runtime dependency of PyGObject is missing.
@@ -51,7 +51,7 @@ def __init__(  # pylint: disable=too-many-arguments
             label="",  # Helpful when visualizing secrets by other viewers
             attribute_types=None,  # {name: SchemaAttributeType, ...}
             collection=None,  # None means default collection
-            ):  # pylint: disable=bad-continuation
+            ):
         """This agent is built on top of lower level libsecret API.
 
         Content stored via libsecret is associated with a bunch of attributes.
@@ -126,7 +126,8 @@ def trial_run():
         agent.save(payload)  # It would fail when running inside an SSH session
         assert agent.load() == payload  # This line is probably not reachable
         agent.clear()
-    except (gi.repository.GLib.Error, AssertionError):
+    except (gi.repository.GLib.Error, AssertionError):  # pylint: disable=no-member
+        # https://pygobject.readthedocs.io/en/latest/guide/api/error_handling.html#examples
         message = """libsecret did not perform properly.
 * If you encountered error "Remote error from secret service:
   org.freedesktop.DBus.Error.ServiceUnknown",

msal_extensions/osx.py

@@ -5,7 +5,7 @@
 import os
 import ctypes as _ctypes
 
-OS_RESULT = _ctypes.c_int32
+OS_RESULT = _ctypes.c_int32  # pylint: disable=invalid-name
 
 
 class KeychainError(OSError):

msal_extensions/persistence.py

@@ -13,7 +13,7 @@
 import sys
 try:
     from pathlib import Path  # Built-in in Python 3
-except:
+except ImportError:
     from pathlib2 import Path  # An extra lib for Python 2
 
 
@@ -59,10 +59,12 @@ class PersistenceNotFound(IOError):  # Use IOError rather than OSError as base,
         # https://github.com/AzureAD/microsoft-authentication-extensions-for-python/blob/0.2.2/msal_extensions/token_cache.py#L38
         # Now we want to maintain backward compatibility even when using Python 2.x
         # It makes no difference in Python 3.3+ where IOError is an alias of OSError.
-    def __init__(
-            self,
-            err_no=errno.ENOENT, message="Persistence not found", location=None):
-        super(PersistenceNotFound, self).__init__(err_no, message, location)
+    """This happens when attempting BasePersistence.load() on a non-existent persistence instance"""
+    def __init__(self, err_no=None, message=None, location=None):
+        super(PersistenceNotFound, self).__init__(
+            err_no or errno.ENOENT,
+            message or "Persistence not found",
+            location)
 
 
 class BasePersistence(ABC):
@@ -220,7 +222,7 @@ def load(self):
             try:
                 return locker.get_generic_password(
                     self._service_name, self._account_name)
-            except self._KeychainError as ex:
+            except self._KeychainError as ex:  # pylint: disable=invalid-name
                 if ex.exit_status == self._KeychainError.ITEM_NOT_FOUND:
                     # This happens when a load() is called before a save().
                     # We map it into cross-platform error for unified catching.