not possible to specify an "index" action for a resource with an empty sub-path

[aetherknight]

Given:

import endpoints
from protorpc import message_types, remote


api_collection = endpoints.api(
    name='someapi',
    version='v1',
    allowed_client_ids=[endpoints.API_EXPLORER_CLIENT_ID],
    scopes=[endpoints.EMAIL_SCOPE]
)

@api_collection.api_class(resource_name='some', path='some')
class SomeApiService(remote.Service):

    @endpoints.method(
        message_types.VoidMessage,
        message_types.VoidMessage,
        path='',
        http_method='GET',
        name='index',
    )
    def some_index(self, request):
        return message_types.VoidMessage()


APPLICATION = endpoints.api_server([api_collection])

I would expect the action's path to be /_ah/api/someapi/v1/some. However, the path is /_ah/api/someapi/v1/some/some_index:

This issue exists in both endpoints framework 1 and 2.0.2.

Root Cause

Within the decorator function created by endpoints.api_config.method(), it performs a truthy check of the provided path, and defaults to the method's __name__ if it is falsey.

    invoke_remote.method_info = _MethodInfo(
        name=name or api_method.__name__, path=path or api_method.__name__,
        http_method=http_method or DEFAULT_HTTP_METHOD,
        scopes=scopes, audiences=audiences,
        allowed_client_ids=allowed_client_ids, auth_level=auth_level,
        api_key_required=api_key_required,
        request_body_class=request_body_class,
        request_params_class=request_params_class)

However, _MethodInfo.get_path() provides explicit handling of an empty string (which never happens due to @endpoints.method not allowing the empty string):

  def get_path(self, api_info):
  ...
    path = self.__path or ''
    if path and path[0] == '/':
      # Absolute path, ignoring any prefixes.  Just strip off the leading /.
      path = path[1:]
    else:
      # Relative path.
      if api_info.path:
        path = '%s%s%s' % (api_info.path, '/' if path else '', path)

    # Verify that the path seems valid.
    for part in path.split('/'):
      if part and '{' in part and '}' in part:
        if re.match('^{[^{}]+}$', part) is None:
          raise api_exceptions.ApiConfigurationError(
              'Invalid path segment: %s (part of %s)' % (part, path))
    return path

This can be worked around, but it requires not using the path argument to @api_collection.api_class() for specifying the path, in order to give each method decorator a non-empty string.