20 - Replaced closure+function to keep state with classes implementing __call__

- Added initial version for setup.cfg
- Added initial documentation for testing

Author: dineshtrivedi

.gitignore

@@ -25,6 +25,7 @@ pip-log.txt
 .coverage
 .tox
 nosetests.xml
+.pytest_cache
 
 # Translations
 *.mo
@@ -33,3 +34,5 @@ nosetests.xml
 .mr.developer.cfg
 .project
 .pydevproject
+.pylint-plugin-utils
+.idea

.travis.yml

@@ -4,6 +4,7 @@ python:
   - "3.5"
   - "3.6"
   - "3.7"
+  - "3.8"
 env:
   - PYLINT=2.0.0
   - PYLINT=2.1.1

README.md

@@ -10,6 +10,34 @@
 
 Utilities and helpers for writing Pylint plugins. This is not a direct Pylint plugin, but rather a set of tools and functions used by other plugins such as [pylint-django](https://github.com/PyCQA/pylint-django) and [pylint-celery](https://github.com/PyCQA/pylint-celery).
 
+# Testing
+We use [tox](https://tox.readthedocs.io/en/latest/) and [pytest-benchmark](https://pytest-benchmark.readthedocs.io/en/latest/index.html) for running the test suite. You should be able to install it with:
+```bash
+pip install tox pytest pytest-benchmark
+```
+
+To run the test suite for a particular Python version, you can do:
+```bash
+tox -e py37
+```
+
+To run individual tests with ``tox``, you can do::
+```bash
+tox -e py37 -- -k name_of_the_test
+```
+
+We use pytest_ for testing ``pylint``, which you can use without using ``tox`` for a faster development cycle.
+
+If you want to run tests on a specific portion of the code with [pytest](https://docs.pytest.org/en/latest/), [pytest-cov](https://pypi.org/project/pytest-cov/) and your local python version::
+```bash
+pip install pytest-cov
+# Everything:
+python3 -m pytest tests/ --cov=pylint_plugin_utils
+coverage html
+```
+
+
+
 # License
 
 `pylint-plugin-utils` is available under the GPLv2 License.

pylint_plugin_utils/__init__.py

@@ -1,6 +1,7 @@
-import sys
+from typing import List
 
 from pylint.exceptions import UnknownMessageError
+from pylint.lint import PyLinter
 
 
 def get_class(module_name, kls):
@@ -21,14 +22,14 @@ def __repr__(self):
         return self.message
 
 
-def get_checker(linter, checker_class):
+def get_checker(linter: PyLinter, checker_class):
     for checker in linter.get_checkers():
         if isinstance(checker, checker_class):
             return checker
     raise NoSuchChecker(checker_class)
 
 
-def augment_visit(linter, checker_method, augmentation):
+def augment_visit(linter: PyLinter, checker_method, augmentation):
     """
     Augmenting a visit enables additional errors to be raised (although that case is
     better served using a new checker) or to suppress all warnings in certain circumstances.
@@ -39,25 +40,34 @@ def augment_visit(linter, checker_method, augmentation):
     prevent any further checking.
     """
 
-    if sys.version_info[0] <= 2:
-        checker = get_checker(linter, checker_method.im_class)
-    else:
-        try:
-            checker = get_checker(linter, checker_method.__self__.__class__)
-        except AttributeError:
-            checker = get_checker(linter, get_class(checker_method.__module__, checker_method.__qualname__))
+    try:
+        checker = get_checker(linter, checker_method.__self__.__class__)
+    except AttributeError:
+        checker = get_checker(linter, get_class(checker_method.__module__, checker_method.__qualname__))
 
     old_method = getattr(checker, checker_method.__name__)
+    setattr(checker, checker_method.__name__, AugmentFunc(old_method, augmentation))
+
+
+class AugmentFunc:
+    def __init__(self, old_method, augmentation_func):
+        self.old_method = old_method
+        self.augmentation_func = augmentation_func
+
+    def __call__(self, node):
+        self.augmentation_func(Chain(self.old_method, node), node)
+
 
-    def augment_func(node):
-        def chain():
-            old_method(node)
-        augmentation(chain, node)
+class Chain:
+    def __init__(self, old_method, node):
+        self.old_method = old_method
+        self.node = node
 
-    setattr(checker, checker_method.__name__, augment_func)
+    def __call__(self):
+        self.old_method(self.node)
 
 
-class Suppress(object):
+class Suppress:
 
     def __init__(self, linter):
         self._linter = linter
@@ -91,31 +101,54 @@ def __exit__(self, exc_type, exc_val, exc_tb):
             self._linter.add_message(*to_append_args, **to_append_kwargs)
 
 
-def supress_message(linter, checker_method, message_id, test_func):
-    import warnings
-    warnings.warn("'supress_message' has been deprecated in favour of the correctly-spelled 'suppress_message'",
-                  DeprecationWarning)
-    return suppress_message(linter, checker_method, message_id, test_func)
-
-
-def suppress_message(linter, checker_method, message_id_or_symbol, test_func):
+def suppress_message(linter: PyLinter, checker_method, message_id_or_symbol, test_func):
     """
     This wrapper allows the suppression of a message if the supplied test function
     returns True. It is useful to prevent one particular message from being raised
     in one particular case, while leaving the rest of the messages intact.
     """
-    # At some point, pylint started preferring message symbols to message IDs. However this is not done
-    # consistently or uniformly - occasionally there are some message IDs with no matching symbols.
-    # We try to work around this here by suppressing both the ID and the symbol, if we can find it.
-    # This also gives us compatability with a broader range of pylint versions.
-
-    # Similarly, a commit between version 1.2 and 1.3 changed where the messages are stored - see:
-    # https://bitbucket.org/logilab/pylint/commits/0b67f42799bed08aebb47babdc9fb0e761efc4ff#chg-reporters/__init__.py
-    # Therefore here, we try the new attribute name, and fall back to the old version for
-    # compatability with <=1.2 and >=1.3
-    msgs_store = getattr(linter, 'msgs_store', linter)
-
-    def get_message_definitions(message_id_or_symbol):
+    augment_visit(linter, checker_method, DoSuppress(linter, message_id_or_symbol, test_func))
+
+
+class DoSuppress:
+    def __init__(self, linter: PyLinter, message_id_or_symbol, test_func):
+        self.linter = linter
+        self.message_id_or_symbol = message_id_or_symbol
+        self.test_func = test_func
+
+    def __call__(self, chain, node):
+        with Suppress(self.linter) as s:
+            if self.test_func(node):
+                s.suppress(*self.symbols)
+            chain()
+
+    @property
+    def symbols(self) -> List:
+        # At some point, pylint started preferring message symbols to message IDs. However this is not done
+        # consistently or uniformly - occasionally there are some message IDs with no matching symbols.
+        # We try to work around this here by suppressing both the ID and the symbol, if we can find it.
+        # This also gives us compatability with a broader range of pylint versions.
+
+        # Similarly, a commit between version 1.2 and 1.3 changed where the messages are stored - see:
+        # https://bitbucket.org/logilab/pylint/commits/0b67f42799bed08aebb47babdc9fb0e761efc4ff#chg-reporters/__init__.py
+        # Therefore here, we try the new attribute name, and fall back to the old version for
+        # compatability with <=1.2 and >=1.3
+
+        try:
+            pylint_messages = self.get_message_definitions(self.message_id_or_symbol)
+            the_symbols = [symbol
+                           for pylint_message in pylint_messages
+                           for symbol in (pylint_message.msgid, pylint_message.symbol)
+                           if symbol is not None]
+        except UnknownMessageError:
+            # This can happen due to mismatches of pylint versions and plugin expectations of available messages
+            the_symbols = [self.message_id_or_symbol]
+
+        return the_symbols
+
+    def get_message_definitions(self, message_id_or_symbol):
+        msgs_store = getattr(self.linter, 'msgs_store', self.linter)
+
         if hasattr(msgs_store, 'check_message_id'):
             return [msgs_store.check_message_id(message_id_or_symbol)]
         # pylint 2.0 renamed check_message_id to get_message_definition in:
@@ -128,20 +161,3 @@ def get_message_definitions(message_id_or_symbol):
             return msgs_store.get_message_definitions(message_id_or_symbol)
         else:
             raise ValueError('pylint.utils.MessagesStore does not have a get_message_definition(s) method')
-
-    try:
-        pylint_messages = get_message_definitions(message_id_or_symbol)
-        symbols = [symbol
-                   for pylint_message in pylint_messages
-                   for symbol in (pylint_message.msgid, pylint_message.symbol)
-                   if symbol is not None]
-    except UnknownMessageError:
-        # This can happen due to mismatches of pylint versions and plugin expectations of available messages
-        symbols = [message_id_or_symbol]
-
-    def do_suppress(chain, node):
-        with Suppress(linter) as s:
-            if test_func(node):
-                s.suppress(*symbols)
-            chain()
-    augment_visit(linter, checker_method, do_suppress)

setup.cfg

@@ -0,0 +1,9 @@
+[aliases]
+test = pytest
+
+[tool:pytest]
+testpaths = tests
+python_files = *test_*.py
+
+[isort]
+profile = black

setup.py

@@ -12,21 +12,27 @@
     'Intended Audience :: Developers',
     'Operating System :: Unix',
     'Topic :: Software Development :: Quality Assurance',
-    'Programming Language :: Python :: 3.5',
+    'Programming Language :: Python',
+    'Programming Language :: Python :: 3'
+    'Programming Language :: Python :: 3 :: Only',
     'Programming Language :: Python :: 3.6',
     'Programming Language :: Python :: 3.7',
+    'Programming Language :: Python :: 3.8',
+    'Programming Language :: Python :: 3.9',
+    'Programming Language :: Python :: 3.10',
 ]
 
 setup(
     name='pylint-plugin-utils',
-    url='https://github.com/landscapeio/pylint-plugin-utils',
-    author='landscape.io',
-    author_email='code@landscape.io',
+    url='https://github.com/PyCQA/pylint-plugin-utils',
+    author='Python Code Quality Authority',
+    author_email='code[email protected]',
     description=_short_description,
     version=_version,
-    install_requires=['pylint>=1.7'],
+    install_requires=['pylint>=1.7', 'pytest'],
     packages=_packages,
     license='GPLv2',
     classifiers=_classifiers,
-    keywords='pylint plugin helpers'
+    keywords='pylint plugin helpers',
+    python_requires='>=3.6.2',
 )

tests.py

@@ -0,0 +1,21 @@
+# pylint: disable=redefined-outer-name
+import os
+from pathlib import Path
+
+import pytest
+
+from pylint import checkers
+from pylint.lint import PyLinter
+from pylint.testutils import MinimalTestReporter
+
+
+@pytest.fixture()
+def tests_directory():
+    return Path(__file__).parent
+
+
+@pytest.fixture
+def linter():
+    _linter = PyLinter()
+    return _linter
+