Resets import path on each request

Ensures the import path is reset before resolving a new request.

This prevents state from previous requests from polluting
subsequent request resolution, particularly when using dynamic
routing and directory mode. A new test case has also been added to
verify this behavior.

Author: paulcruse3

acai_aws/apigateway/resolver/modes/directory.py

@@ -4,11 +4,15 @@
 
 class DirectoryModeResolver(BaseModeResolver):
 
+    INIT_FILE = '__init__.py'
+
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
         self.__handler_path = self.importer.clean_path(kwargs['handlers'])
 
     def _get_file_and_import_path(self, request_path):
+        # ensure previous lookups don't leave behind path/dynamic state
+        self.reset()
         split_path = self.get_request_path_as_list(request_path)
         route_path = self.__get_route_path(split_path)
         file_path = self.__handler_path + self.importer.file_separator + route_path
@@ -25,7 +29,7 @@ def __get_import_path_file_tree(self, split_path, split_index, file_tree):
             part = split_path[split_index]
             if part == '':
                 possible_directory = None
-                possible_file = '__init__.py'
+                possible_file = self.INIT_FILE
             else:
                 possible_directory = part.replace('-', '_')
                 possible_file = f'{possible_directory}.py'
@@ -44,7 +48,7 @@ def __handle_directory_path_part(self, possible_directory, split_path, split_ind
             file_leaf = self.determine_which_file_leaf(file_tree, possible_directory)
             self.__get_import_path_file_tree(split_path, split_index+1, file_leaf)
         else:
-            self.append_import_path('__init__.py')
+            self.append_import_path(self.INIT_FILE)
 
     def __handle_file_path_part(self, possible_file, split_path, split_index, file_tree):
         self.append_import_path(possible_file)
@@ -55,7 +59,7 @@ def __handle_dynamic_path_part(self, split_path, split_index, file_tree):
         file_part = list(file_tree['__dynamic_files'])[0]
         self.append_import_path(file_part)
         if '.py' not in file_part and split_index+1 == len(split_path):
-            self.append_import_path('__init__.py')
+            self.append_import_path(self.INIT_FILE)
         file_leaf = self.determine_which_file_leaf(file_tree, file_part)
         self.has_dynamic_route = True
         self.dynamic_parts[split_index] = split_path[split_index]

tests/acai_aws/apigateway/resolver/modes/test_directory.py

@@ -121,3 +121,10 @@ def test_triple_nested_dynamic_get_file_and_import_path(self):
         file_path, import_path = self.directory_resolver._get_file_and_import_path(request.path)
         self.assertTrue('tests/mocks/apigateway/resolver/directory_handlers/user/_user_id/item/_item_id.py' in file_path)
         self.assertEqual('tests.mocks.apigateway.resolver.directory_handlers.user._user_id.item._item_id', import_path)
+
+    def test_repeated_directory_request_resets_import_path(self):
+        request = Request(self.init_request)
+        first_file_path, first_import_path = self.directory_resolver._get_file_and_import_path(request.path)
+        second_file_path, second_import_path = self.directory_resolver._get_file_and_import_path(request.path)
+        self.assertEqual(first_file_path, second_file_path)
+        self.assertEqual(first_import_path, second_import_path)