Add the skeleton for the LegacyStyleGuide

src/flake8/api/style_guide.py

@@ -0,0 +1,47 @@
+"""Module containing shims around Flake8 2.0 behaviour."""
+import os.path
+
+from flake8.formatting import base as formatter
+
+
+class LegacyStyleGuide(object):
+    """Public facing object that mimic's Flake8 2.0's StyleGuide."""
+
+    def __init__(self, application):
+        self._application = application
+        self._file_checker_manager = application.file_checker_manager
+
+    @property
+    def options(self):
+        """The parsed options.
+
+        An instance of :class:`optparse.Values` containing parsed options.
+        """
+        return self._application.options
+
+    @property
+    def paths(self):
+        """The extra arguments passed as paths."""
+        return self._application.paths
+
+    def check_files(self, paths=None):
+        raise NotImplementedError('This should be easy')
+
+    def excluded(self, filename, parent=None):
+        return (self._file_checker_manager.is_path_excluded(filename) or
+                (parent and
+                    self._file_checker_manager.is_path_excluded(
+                        os.path.join(parent, filename))))
+
+    def init_report(self, reporter=None):
+        if (reporter is not None and
+                isinstance(reporter, formatter.BaseFormatter)):
+            self._application.formatter = reporter
+            self._application.guide = None
+            # NOTE(sigmavirus24): This isn't the intended use of
+            # Application#make_guide but it works pretty well.
+            # Stop cringing... I know it's gross.
+            self._application.make_guide()
+
+    def input_file(self, filename, lines=None, expected=None, line_offset=0):
+        raise NotImplementedError('This should be a pain')