Fix split path function

So it also works on windows
and does not return empty stuff
and update tests

django_migration_linter/utils.py

@@ -42,14 +42,28 @@ def find_project_settings_module(path):
             if file_name == "settings.py":
                 return (
                     os.path.join(root.replace(path, ""), file_name)
-                    .replace("/", ".")
+                    .replace(os.sep, ".")
                     .rstrip(".py")
                 )
 
 
 def split_path(path):
-    a, b = os.path.split(path)
-    return (split_path(a) if (len(a) > 0 and a != "/") else []) + ([b] if b else [])
+    decomposed_path = []
+    while 1:
+        head, tail = os.path.split(path)
+        if head == path:  # sentinel for absolute paths
+            decomposed_path.insert(0, head)
+            break
+        elif tail == path:  # sentinel for relative paths
+            decomposed_path.insert(0, tail)
+            break
+        else:
+            path = head
+            decomposed_path.insert(0, tail)
+
+    if not decomposed_path[-1]:
+        decomposed_path = decomposed_path[:-1]
+    return decomposed_path
 
 
 def split_migration_path(migration_path):

tests/unit/test_utils.py

@@ -44,25 +44,27 @@ class UtilityFunctionTest(unittest.TestCase):
         actual = find_project_settings_module(fixtures.CORRECT_PROJECT)
         self.assertEqual(actual, expected)
 
+
+class SplitPathTest(unittest.TestCase):
     def test_split_path(self):
-        splitted = split_path('foo/bar/fuz.py')
-        self.assertEqual(len(splitted), 3)
-        self.assertEqual(splitted[0], 'foo')
-        self.assertEqual(splitted[1], 'bar')
-        self.assertEqual(splitted[2], 'fuz.py')
+        split = split_path('foo/bar/fuz.py')
+        self.assertEqual(split, ["foo", "bar", "fuz.py"])
 
     def test_split_full_path(self):
-        splitted = split_path('/foo/bar/fuz.py')
-        self.assertEqual(len(splitted), 3)
-        self.assertEqual(splitted[0], 'foo')
-        self.assertEqual(splitted[1], 'bar')
-        self.assertEqual(splitted[2], 'fuz.py')
+        split = split_path('/foo/bar/fuz.py')
+        self.assertEqual(split, ["/", "foo", "bar", "fuz.py"])
 
     def test_split_folder_path(self):
-        splitted = split_path('/foo/bar')
-        self.assertEqual(len(splitted), 2)
-        self.assertEqual(splitted[0], 'foo')
-        self.assertEqual(splitted[1], 'bar')
+        split = split_path('/foo/bar')
+        self.assertEqual(split, ["/", "foo", "bar"])
+
+    def test_split_folder_path_trailing_slash(self):
+        split = split_path('/foo/bar/')
+        self.assertEqual(split, ["/", "foo", "bar"])
+
+    def test_split_folder_path_trailing_slashes(self):
+        split = split_path('/foo/bar///')
+        self.assertEqual(split, ["/", "foo", "bar"])
 
     def test_split_migration_long_path(self):
         input_path = 'apps/the_app/migrations/0001_stuff.py'