Merge branch 'entrypoints' into 'master'

Replace setuptools with entrypoints

See merge request pycqa/flake8!264

9 files changed, 59 insertions, 115 deletions

diff --git a/setup.py b/setup.py
index e2adfbf..24e8996 100644
--- a/setup.py
+++ b/setup.py
@@ -21,10 +21,10 @@ requires = [
     # http://flake8.pycqa.org/en/latest/faq.html#why-does-flake8-use-ranges-for-its-dependencies
     # And in which releases we will update those ranges here:
     # http://flake8.pycqa.org/en/latest/internal/releases.html#releasing-flake8
+    "entrypoints >= 0.2.3, < 0.3.0",
     "pyflakes >= 2.0.0, < 2.1.0",
     "pycodestyle >= 2.4.0, < 2.5.0",
     "mccabe >= 0.6.0, < 0.7.0",
-    "setuptools >= 30",
 ]
 
 extras_require = {
diff --git a/src/flake8/main/application.py b/src/flake8/main/application.py
index b86b3cc..86d7fd4 100644
--- a/src/flake8/main/application.py
+++ b/src/flake8/main/application.py
@@ -169,7 +169,7 @@ class Application(object):
         If :attr:`check_plugins`, :attr:`listening_plugins`, or
         :attr:`formatting_plugins` are ``None`` then this method will update
         them with the appropriate plugin manager instance. Given the expense
-        of finding plugins (via :mod:`pkg_resources`) we want this to be
+        of finding plugins (via :mod:`entrypoints`) we want this to be
         idempotent and so only update those attributes if they are ``None``.
         """
         if self.local_plugins is None:
@@ -238,16 +238,7 @@ class Application(object):
 
     def formatter_for(self, formatter_plugin_name):
         """Retrieve the formatter class by plugin name."""
-        try:
-            default_formatter = self.formatting_plugins["default"]
-        except KeyError:
-            raise exceptions.ExecutionError(
-                "The 'default' Flake8 formatting plugin is unavailable. "
-                "This usually indicates that your setuptools is too old. "
-                "Please upgrade setuptools. If that does not fix the issue"
-                " please file an issue."
-            )
-
+        default_formatter = self.formatting_plugins["default"]
         formatter_plugin = self.formatting_plugins.get(formatter_plugin_name)
         if formatter_plugin is None:
             LOG.warning(
diff --git a/src/flake8/main/debug.py b/src/flake8/main/debug.py
index 51bac9a..e02da6b 100644
--- a/src/flake8/main/debug.py
+++ b/src/flake8/main/debug.py
@@ -4,6 +4,8 @@ from __future__ import print_function
 import json
 import platform
 
+import entrypoints
+
 
 def print_information(
     option, option_string, value, parser, option_manager=None
@@ -64,7 +66,4 @@ def plugins_from(option_manager):
 
 def dependencies():
     """Generate the list of dependencies we care about."""
-    # defer this expensive import, not used outside --bug-report
-    import setuptools
-
-    return [{"dependency": "setuptools", "version": setuptools.__version__}]
+    return [{"dependency": "entrypoints", "version": entrypoints.__version__}]
diff --git a/src/flake8/plugins/manager.py b/src/flake8/plugins/manager.py
index 6d0cf99..010cfb9 100644
--- a/src/flake8/plugins/manager.py
+++ b/src/flake8/plugins/manager.py
@@ -2,7 +2,7 @@
 import logging
 import sys
 
-import pkg_resources
+import entrypoints
 
 from flake8 import exceptions
 from flake8 import utils
@@ -143,17 +143,8 @@ class Plugin(object):
         r"""Call the plugin with \*args and \*\*kwargs."""
         return self.plugin(*args, **kwargs)  # pylint: disable=not-callable
 
-    def _load(self, verify_requirements):
-        # Avoid relying on hasattr() here.
-        resolve = getattr(self.entry_point, "resolve", None)
-        require = getattr(self.entry_point, "require", None)
-        if resolve and require:
-            if verify_requirements:
-                LOG.debug('Verifying plugin "%s"\'s requirements.', self.name)
-                require()
-            self._plugin = resolve()
-        else:
-            self._plugin = self.entry_point.load(require=verify_requirements)
+    def _load(self):
+        self._plugin = self.entry_point.load()
         if not callable(self._plugin):
             msg = (
                 "Plugin %r is not a callable. It might be written for an"
@@ -171,15 +162,14 @@ class Plugin(object):
         cached plugin.
 
         :param bool verify_requirements:
-            Whether or not to make setuptools verify that the requirements for
-            the plugin are satisfied.
+            Does nothing, retained for backwards compatibility.
         :returns:
             Nothing
         """
         if self._plugin is None:
             LOG.info('Loading plugin "%s" from entry-point.', self.name)
             try:
-                self._load(verify_requirements)
+                self._load()
             except Exception as load_exception:
                 LOG.exception(load_exception)
                 failed_to_load = exceptions.FailedToLoadPlugin(
@@ -256,11 +246,9 @@ class PluginManager(object):  # pylint: disable=too-few-public-methods
         :param list local_plugins:
             Plugins from config (as "X = path.to:Plugin" strings).
         :param bool verify_requirements:
-            Whether or not to make setuptools verify that the requirements for
-            the plugin are satisfied.
+            Does nothing, retained for backwards compatibility.
         """
         self.namespace = namespace
-        self.verify_requirements = verify_requirements
         self.plugins = {}
         self.names = []
         self._load_local_plugins(local_plugins or [])
@@ -273,12 +261,14 @@ class PluginManager(object):  # pylint: disable=too-few-public-methods
             Plugins from config (as "X = path.to:Plugin" strings).
         """
         for plugin_str in local_plugins:
-            entry_point = pkg_resources.EntryPoint.parse(plugin_str)
+            name, _, entry_str = plugin_str.partition("=")
+            name, entry_str = name.strip(), entry_str.strip()
+            entry_point = entrypoints.EntryPoint.from_string(entry_str, name)
             self._load_plugin_from_entrypoint(entry_point, local=True)
 
     def _load_entrypoint_plugins(self):
         LOG.info('Loading entry-points for "%s".', self.namespace)
-        for entry_point in pkg_resources.iter_entry_points(self.namespace):
+        for entry_point in entrypoints.get_group_all(self.namespace):
             self._load_plugin_from_entrypoint(entry_point)
 
     def _load_plugin_from_entrypoint(self, entry_point, local=False):
diff --git a/tests/integration/test_checker.py b/tests/integration/test_checker.py
index 6877470..3d10bfb 100644
--- a/tests/integration/test_checker.py
+++ b/tests/integration/test_checker.py
@@ -51,13 +51,12 @@ def plugin_func_list(tree):
 def test_handle_file_plugins(plugin_target):
     """Test the FileChecker class handling different file plugin types."""
     # Mock an entry point returning the plugin target
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     entry_point.name = plugin_target.name
-    entry_point.resolve.return_value = plugin_target
+    entry_point.load.return_value = plugin_target
 
     # Load the checker plugins using the entry point mock
-    with mock.patch('pkg_resources.iter_entry_points',
-                    return_value=[entry_point]):
+    with mock.patch('entrypoints.get_group_all', return_value=[entry_point]):
         checks = manager.Checkers()
 
     # Prevent it from reading lines from stdin or somewhere else
diff --git a/tests/unit/test_application.py b/tests/unit/test_application.py
index a281012..5ec9f1f 100644
--- a/tests/unit/test_application.py
+++ b/tests/unit/test_application.py
@@ -4,7 +4,6 @@ import optparse
 import mock
 import pytest
 
-from flake8 import exceptions
 from flake8.main import application as app
 
 
@@ -61,14 +60,6 @@ def test_exit_does_raise(result_count, catastrophic, exit_zero, value,
     assert excinfo.value.args[0] is value
 
 
-def test_missing_default_formatter(application):
-    """Verify we raise an ExecutionError when there's no default formatter."""
-    application.formatting_plugins = {}
-
-    with pytest.raises(exceptions.ExecutionError):
-        application.formatter_for('fake-plugin-name')
-
-
 def test_warns_on_unknown_formatter_plugin_name(application):
     """Verify we log a warning with an unfound plugin."""
     default = mock.Mock()
diff --git a/tests/unit/test_debug.py b/tests/unit/test_debug.py
index 7253bcc..0d1f903 100644
--- a/tests/unit/test_debug.py
+++ b/tests/unit/test_debug.py
@@ -1,7 +1,7 @@
 """Tests for our debugging module."""
+import entrypoints
 import mock
 import pytest
-import setuptools
 
 from flake8.main import debug
 from flake8.options import manager
@@ -9,8 +9,8 @@ from flake8.options import manager
 
 def test_dependencies():
     """Verify that we format our dependencies appropriately."""
-    expected = [{'dependency': 'setuptools',
-                 'version': setuptools.__version__}]
+    expected = [{'dependency': 'entrypoints',
+                 'version': entrypoints.__version__}]
     assert expected == debug.dependencies()
 
 
@@ -46,8 +46,8 @@ def test_information(system, pyversion, pyimpl):
                      'is_local': False},
                     {'plugin': 'pycodestyle', 'version': '2.0.0',
                      'is_local': False}],
-        'dependencies': [{'dependency': 'setuptools',
-                          'version': setuptools.__version__}],
+        'dependencies': [{'dependency': 'entrypoints',
+                          'version': entrypoints.__version__}],
         'platform': {
             'python_implementation': 'CPython',
             'python_version': '3.5.3',
diff --git a/tests/unit/test_plugin.py b/tests/unit/test_plugin.py
index 84f676a..4d5510f 100644
--- a/tests/unit/test_plugin.py
+++ b/tests/unit/test_plugin.py
@@ -14,48 +14,24 @@ def test_load_plugin_fallsback_on_old_setuptools():
     plugin = manager.Plugin('T000', entry_point)
 
     plugin.load_plugin()
-    entry_point.load.assert_called_once_with(require=False)
-
-
-def test_load_plugin_avoids_deprecated_entry_point_methods():
-    """Verify we use the preferred methods on new versions of setuptools."""
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
-    plugin = manager.Plugin('T000', entry_point)
-
-    plugin.load_plugin(verify_requirements=True)
-    assert entry_point.load.called is False
-    entry_point.require.assert_called_once_with()
-    entry_point.resolve.assert_called_once_with()
+    entry_point.load.assert_called_once_with()
 
 
 def test_load_plugin_is_idempotent():
     """Verify we use the preferred methods on new versions of setuptools."""
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     plugin = manager.Plugin('T000', entry_point)
 
-    plugin.load_plugin(verify_requirements=True)
-    plugin.load_plugin(verify_requirements=True)
     plugin.load_plugin()
-    assert entry_point.load.called is False
-    entry_point.require.assert_called_once_with()
-    entry_point.resolve.assert_called_once_with()
-
-
-def test_load_plugin_only_calls_require_when_verifying_requirements():
-    """Verify we do not call require when verify_requirements is False."""
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
-    plugin = manager.Plugin('T000', entry_point)
-
     plugin.load_plugin()
-    assert entry_point.load.called is False
-    assert entry_point.require.called is False
-    entry_point.resolve.assert_called_once_with()
+    plugin.load_plugin()
+    entry_point.load.assert_called_once_with()
 
 
 def test_load_plugin_catches_and_reraises_exceptions():
     """Verify we raise our own FailedToLoadPlugin."""
-    entry_point = mock.Mock(spec=['require', 'resolve'])
-    entry_point.resolve.side_effect = ValueError('Test failure')
+    entry_point = mock.Mock(spec=['load'])
+    entry_point.load.side_effect = ValueError('Test failure')
     plugin = manager.Plugin('T000', entry_point)
 
     with pytest.raises(exceptions.FailedToLoadPlugin):
@@ -64,27 +40,27 @@ def test_load_plugin_catches_and_reraises_exceptions():
 
 def test_load_noncallable_plugin():
     """Verify that we do not load a non-callable plugin."""
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
-    entry_point.resolve.return_value = mock.NonCallableMock()
+    entry_point = mock.Mock(spec=['load'])
+    entry_point.load.return_value = mock.NonCallableMock()
     plugin = manager.Plugin('T000', entry_point)
 
     with pytest.raises(exceptions.FailedToLoadPlugin):
         plugin.load_plugin()
-    entry_point.resolve.assert_called_once_with()
+    entry_point.load.assert_called_once_with()
 
 
 def test_plugin_property_loads_plugin_on_first_use():
     """Verify that we load our plugin when we first try to use it."""
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     plugin = manager.Plugin('T000', entry_point)
 
     assert plugin.plugin is not None
-    entry_point.resolve.assert_called_once_with()
+    entry_point.load.assert_called_once_with()
 
 
 def test_execute_calls_plugin_with_passed_arguments():
     """Verify that we pass arguments directly to the plugin."""
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     plugin_obj = mock.Mock()
     plugin = manager.Plugin('T000', entry_point)
     plugin._plugin = plugin_obj
@@ -96,13 +72,11 @@ def test_execute_calls_plugin_with_passed_arguments():
 
     # Extra assertions
     assert entry_point.load.called is False
-    assert entry_point.require.called is False
-    assert entry_point.resolve.called is False
 
 
 def test_version_proxies_to_the_plugin():
     """Verify that we pass arguments directly to the plugin."""
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     plugin_obj = mock.Mock(spec_set=['version'])
     plugin_obj.version = 'a.b.c'
     plugin = manager.Plugin('T000', entry_point)
@@ -114,7 +88,7 @@ def test_version_proxies_to_the_plugin():
 def test_register_options():
     """Verify we call add_options on the plugin only if it exists."""
     # Set up our mocks and Plugin object
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     plugin_obj = mock.Mock(spec_set=['name', 'version', 'add_options',
                                      'parse_options'])
     option_manager = mock.Mock(spec=['register_plugin'])
@@ -131,7 +105,7 @@ def test_register_options():
 def test_register_options_checks_plugin_for_method():
     """Verify we call add_options on the plugin only if it exists."""
     # Set up our mocks and Plugin object
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     plugin_obj = mock.Mock(spec_set=['name', 'version', 'parse_options'])
     option_manager = mock.Mock(spec=['register_plugin'])
     plugin = manager.Plugin('T000', entry_point)
@@ -147,7 +121,7 @@ def test_register_options_checks_plugin_for_method():
 def test_provide_options():
     """Verify we call add_options on the plugin only if it exists."""
     # Set up our mocks and Plugin object
-    entry_point = mock.Mock(spec=['require', 'resolve', 'load'])
+    entry_point = mock.Mock(spec=['load'])
     plugin_obj = mock.Mock(spec_set=['name', 'version', 'add_options',
                                      'parse_options'])
     option_values = optparse.Values({'enable_extensions': []})
diff --git a/tests/unit/test_plugin_manager.py b/tests/unit/test_plugin_manager.py
index 9019ead..72959b0 100644
--- a/tests/unit/test_plugin_manager.py
+++ b/tests/unit/test_plugin_manager.py
@@ -11,51 +11,51 @@ def create_entry_point_mock(name):
     return ep
 
 
-@mock.patch('pkg_resources.iter_entry_points')
-def test_calls_pkg_resources_on_instantiation(iter_entry_points):
-    """Verify that we call iter_entry_points when we create a manager."""
-    iter_entry_points.return_value = []
-    manager.PluginManager(namespace='testing.pkg_resources')
+@mock.patch('entrypoints.get_group_all')
+def test_calls_entrypoints_on_instantiation(get_group_all):
+    """Verify that we call get_group_all when we create a manager."""
+    get_group_all.return_value = []
+    manager.PluginManager(namespace='testing.entrypoints')
 
-    iter_entry_points.assert_called_once_with('testing.pkg_resources')
+    get_group_all.assert_called_once_with('testing.entrypoints')
 
 
-@mock.patch('pkg_resources.iter_entry_points')
-def test_calls_pkg_resources_creates_plugins_automaticaly(iter_entry_points):
+@mock.patch('entrypoints.get_group_all')
+def test_calls_entrypoints_creates_plugins_automaticaly(get_group_all):
     """Verify that we create Plugins on instantiation."""
-    iter_entry_points.return_value = [
+    get_group_all.return_value = [
         create_entry_point_mock('T100'),
         create_entry_point_mock('T200'),
     ]
-    plugin_mgr = manager.PluginManager(namespace='testing.pkg_resources')
+    plugin_mgr = manager.PluginManager(namespace='testing.entrypoints')
 
-    iter_entry_points.assert_called_once_with('testing.pkg_resources')
+    get_group_all.assert_called_once_with('testing.entrypoints')
     assert 'T100' in plugin_mgr.plugins
     assert 'T200' in plugin_mgr.plugins
     assert isinstance(plugin_mgr.plugins['T100'], manager.Plugin)
     assert isinstance(plugin_mgr.plugins['T200'], manager.Plugin)
 
 
-@mock.patch('pkg_resources.iter_entry_points')
-def test_handles_mapping_functions_across_plugins(iter_entry_points):
+@mock.patch('entrypoints.get_group_all')
+def test_handles_mapping_functions_across_plugins(get_group_all):
     """Verify we can use the PluginManager call functions on all plugins."""
     entry_point_mocks = [
         create_entry_point_mock('T100'),
         create_entry_point_mock('T200'),
     ]
-    iter_entry_points.return_value = entry_point_mocks
-    plugin_mgr = manager.PluginManager(namespace='testing.pkg_resources')
+    get_group_all.return_value = entry_point_mocks
+    plugin_mgr = manager.PluginManager(namespace='testing.entrypoints')
     plugins = [plugin_mgr.plugins[name] for name in plugin_mgr.names]
 
     assert list(plugin_mgr.map(lambda x: x)) == plugins
 
 
-@mock.patch('pkg_resources.iter_entry_points')
-def test_local_plugins(iter_entry_points):
+@mock.patch('entrypoints.get_group_all')
+def test_local_plugins(get_group_all):
     """Verify PluginManager can load given local plugins."""
-    iter_entry_points.return_value = []
+    get_group_all.return_value = []
     plugin_mgr = manager.PluginManager(
-        namespace='testing.pkg_resources',
+        namespace='testing.entrypoints',
         local_plugins=['X = path.to:Plugin']
     )