Erroneous mypy specifications

[artivis]

Edit:
I've been using import_message_from_namespaced_type wrong due to misleading erroneous mypy specifications

def import_message_from_namespaced_type(message_type: NamespacedType)

Leaving this issue open until the specification get fixed.

Original:

Bug report

Required Info:

• Operating System:
  • Ubuntu 18.04
• Installation type:
  • source
• Version or commit hash:
  • 2d8af1e
• DDS implementation:
  • Fast-RTPS
• Client library (if applicable):
  • rclpy

Steps to reproduce issue

from rosidl_parser.definition import NamespacedType
from rosidl_runtime_py.import_message import import_message_from_namespaced_type

message = import_message_from_namespaced_type(
            NamespacedType(['std_msgs', 'msg'], 'Bool'))

Expected behavior

Imports a std_msgs/msg/Bool

Actual behavior

Crash

AttributeError: 'NamespacedType' object has no attribute 'value_type'

Additional information

Crash comes from import_message_from_namespaced_type which expects a NamespacedType for input arg. NamespacedType expects as input args Iterable[str], str.

NamespacedType has base AbstractNestableType whereas the '__slots__' value_type comes from AbstractNestedType. Am I missing something or is it a bug ?

[dirk-thomas]

I would guess the annotation is just wrong. This is how it is being used:

rosidl_python/rosidl_runtime_py/rosidl_runtime_py/set_message.py

Lines 52 to 53 in 6ec55cb

	if isinstance(rosidl_type.value_type, NamespacedType):
	field_elem_type = import_message_from_namespaced_type(rosidl_type)

Maybe @mikaelarguedas can comment since he wrote this in #33.

[mikaelarguedas]

Yeah that's definitely a bug. I must have mixed up the types when rebasing/updating #33.

See #74 for a fix making the function behave as specified