fix: Add skill handler directory in pythonpath, for local imports

This commit adds the skill handler directory into the PYTHONPATH variable, so that while running the skill handler file, local python modules/packages imports works as expected. This is to stimulate the behavior of running the skill lambda handler as the main file from the python interpreter.

Author: nikhilym

ask-sdk-local-debug/ask_sdk_local_debug/config/skill_invoker_config.py

@@ -15,6 +15,8 @@
 # specific language governing permissions and limitations under the
 # License.
 #
+import os
+import sys
 import typing
 import importlib.util
 
@@ -82,8 +84,22 @@ def __initialize_skill_invoker(self):
                     self.skill_file_path, str(e)))
         return skill_invoker
 
+    def __load_skill_handler_dir_path(self):
+        # type: () -> None
+        """Loads skill handler directory path into PYTHONPATH.
+
+        For local module/package resolution, this method loads the
+        directory containing the skill handler file into the
+        python path, so that the interpreter will be able to resolve
+        the needed imports during runtime.
+        """
+        skill_dir = os.path.dirname(self.skill_file_path)
+        if skill_dir not in sys.path:
+            sys.path.append(skill_dir)
+
     def __get_skill_builder_func(self):
         try:
+            self.__load_skill_handler_dir_path()
             return getattr(self.__initialize_skill_invoker(), self.skill_handler)
         except Exception as e:
             raise LocalDebugSdkException(