WIP

flake8_isort.py

@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 from isort import SortImports
 
+import os
+
 
 class Flake8Isort(object):
     name = 'flake8_isort'
@@ -10,7 +12,40 @@ class Flake8Isort(object):
     def __init__(self, tree, filename):
         self.filename = filename
 
+    @classmethod
+    def add_options(cls, parser):
+        parser.add_option(
+            '--force-isort-config',
+            action='store_true',
+            help='Require an .isort.cfg file to be found'
+        )
+        parser.config_options.append('force-isort-config')
+
+    @classmethod
+    def parse_options(cls, options):
+        cls.isort_config = options.force_isort_config
+
     def run(self):
-        sort_result = SortImports(self.filename, check=True)
-        if sort_result.incorrectly_sorted:
-            yield 0, 0, self.message, type(self)
+        if self.isort_config and not self.search_isort_config():
+            yield 0, 0, 'I002 no .isort.cfg file found', type(self)
+        else:
+            sort_result = SortImports(self.filename, check=True)
+            if sort_result.incorrectly_sorted:
+                yield 0, 0, self.message, type(self)
+
+    def search_isort_config(self):
+        """Search for a .isort.cfg all the way up to the root folder"""
+        full_path = os.path.abspath(self.filename)
+        path_parts = full_path.split(os.path.sep)
+        dirs_missing = len(path_parts)
+
+        while dirs_missing > 0:
+            dirs_missing -= 1
+            partial_parts = path_parts[:dirs_missing]
+            partial_path = os.sep.join(partial_parts)
+
+            isort_file = '{0}{1}.isort.cfg'.format(partial_path, os.sep)
+            if os.path.exists(isort_file):
+                return True
+
+        return False