config: Switch code paths to use 'ConfigFileFinder.config_file'

Now that the `ConfigFileFinder` has the `.config_file` attribute, switch
the relevant code paths to utilize this public attribute.

Tests have been updated to either construct `ConfigFileFinder` or mock
the object appropriately.

src/flake8/options/config.py

@@ -317,14 +317,14 @@ class MergedConfigParser(object):
             )
             return {}
 
-        if cli_config:
+        if self.config_finder.config_file:
             LOG.debug(
                 "Ignoring user and locally found configuration files. "
                 'Reading only configuration from "%s" specified via '
                 "--config by the user",
-                cli_config,
+                self.config_finder.config_file,
             )
-            return self.parse_cli_config(cli_config)
+            return self.parse_cli_config(self.config_finder.config_file)
 
         return self.merge_user_and_local_config()
 
@@ -351,14 +351,14 @@ def get_local_plugins(config_finder, cli_config=None):
         )
         return local_plugins
 
-    if cli_config:
+    if config_finder.config_file:
         LOG.debug(
             'Reading local plugins only from "%s" specified via '
             "--config by the user",
-            cli_config,
+            config_finder.config_file,
         )
-        config = config_finder.cli_config(cli_config)
-        config_files = [cli_config]
+        config = config_finder.cli_config(config_finder.config_file)
+        config_files = [config_finder.config_file]
     else:
         config, config_files = config_finder.local_configs_with_files()
 

tests/integration/test_aggregator.py

@@ -30,7 +30,10 @@ def test_aggregate_options_with_config(optmanager):
     """Verify we aggregate options and config values appropriately."""
     arguments = ['flake8', '--select',
                  'E11,E34,E402,W,F', '--exclude', 'tests/*']
-    config_finder = config.ConfigFileFinder('flake8', [])
+    config_finder = config.ConfigFileFinder(
+        'flake8',
+        [],
+        config_file=CLI_SPECIFIED_CONFIG)
     options, args = aggregator.aggregate_options(
         optmanager, config_finder, CLI_SPECIFIED_CONFIG, arguments)
 

tests/unit/test_get_local_plugins.py

@@ -24,10 +24,12 @@ def test_get_local_plugins_uses_cli_config():
     config_finder.cli_config.return_value = config_obj
     config_finder.ignore_config_files = False
     config_obj.get.return_value = ''
+    config_file_value = 'foo.ini'
+    config_finder.config_file = config_file_value
 
-    config.get_local_plugins(config_finder, cli_config='foo.ini')
+    config.get_local_plugins(config_finder, cli_config=config_file_value)
 
-    config_finder.cli_config.assert_called_once_with('foo.ini')
+    config_finder.cli_config.assert_called_once_with(config_file_value)
 
 
 def test_get_local_plugins():

tests/unit/test_merged_config_parser.py

@@ -155,12 +155,14 @@ def test_parse_isolates_config(optmanager):
 
 def test_parse_uses_cli_config(optmanager):
     """Verify behaviour of the parse method with a specified config."""
+    config_file_value = 'foo.ini'
     config_finder = mock.MagicMock()
+    config_finder.config_file = config_file_value
     config_finder.ignore_config_files = False
     parser = config.MergedConfigParser(optmanager, config_finder)
 
-    parser.parse(cli_config='foo.ini')
-    config_finder.cli_config.assert_called_once_with('foo.ini')
+    parser.parse(cli_config=config_file_value)
+    config_finder.cli_config.assert_called_once_with(config_file_value)
 
 
 @pytest.mark.parametrize('config_fixture_path', [