Static typing for Message, Services, and Actions (#206)

Signed-off-by: Michael Carlstrom <rmc@carlstrom.com>
Signed-off-by: Michael Carlstrom <36806982+InvincibleRMC@users.noreply.github.com>
Signed-off-by: Shane Loretz <shane.loretz@gmail.com>
Co-authored-by: Shane Loretz <shane.loretz@gmail.com>
Co-authored-by: Christophe Bedard <bedard.christophe@gmail.com>

Author: 3 people

rosidl_generator_py/cmake/rosidl_generator_py_generate_interfaces.cmake

@@ -301,5 +301,10 @@ if(BUILD_TESTING AND rosidl_generate_interfaces_ADD_LINTER_TESTS)
       # a value of zero tells uncrustify to ignore line length
       MAX_LINE_LENGTH 0
       "${_output_path}")
+
+    find_package(ament_cmake_mypy REQUIRED)
+    ament_mypy(
+      TESTNAME "mypy_rosidl_generated_py"
+      "${_output_path}")
   endif()
 endif()

rosidl_generator_py/package.xml

@@ -35,6 +35,7 @@
   <exec_depend>ament_cmake_cppcheck</exec_depend>
   <exec_depend>ament_cmake_cpplint</exec_depend>
   <exec_depend>ament_cmake_flake8</exec_depend>
+  <exec_depend>ament_cmake_mypy</exec_depend>
   <exec_depend>ament_cmake_pep257</exec_depend>
   <exec_depend>ament_cmake_uncrustify</exec_depend>
 

rosidl_generator_py/py.typed

@@ -5,40 +5,50 @@ from rosidl_pycommon import convert_camel_case_to_lower_case_underscore
 action_name = '_' + convert_camel_case_to_lower_case_underscore(action.namespaced_type.name)
 module_name = '_' + convert_camel_case_to_lower_case_underscore(interface_path.stem)
 
+type_annotations_import_statements.add(f'from {".".join(action.namespaced_type.namespaces)}.{module_name} import {action.goal.structure.namespaced_type.name}')
+type_annotations_import_statements.add(f'from {".".join(action.namespaced_type.namespaces)}.{module_name} import {action.result.structure.namespaced_type.name}')
+type_annotations_import_statements.add(f'from {".".join(action.namespaced_type.namespaces)}.{module_name} import {action.feedback.structure.namespaced_type.name}')
+
 TEMPLATE(
     '_msg.py.em',
     package_name=package_name, interface_path=interface_path,
-    message=action.goal, import_statements=import_statements)
+    message=action.goal, import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 TEMPLATE(
     '_msg.py.em',
     package_name=package_name, interface_path=interface_path,
-    message=action.result, import_statements=import_statements)
+    message=action.result, import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 TEMPLATE(
     '_msg.py.em',
     package_name=package_name, interface_path=interface_path,
-    message=action.feedback, import_statements=import_statements)
+    message=action.feedback, import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 TEMPLATE(
     '_srv.py.em',
     package_name=package_name, interface_path=interface_path,
-    service=action.send_goal_service, import_statements=import_statements)
+    service=action.send_goal_service, import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 TEMPLATE(
     '_srv.py.em',
     package_name=package_name, interface_path=interface_path,
-    service=action.get_result_service, import_statements=import_statements)
+    service=action.get_result_service, import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 TEMPLATE(
     '_msg.py.em',
     package_name=package_name, interface_path=interface_path,
-    message=action.feedback_message, import_statements=import_statements)
+    message=action.feedback_message, import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 }@
 
 
 class Metaclass_@(action.namespaced_type.name)(type):
     """Metaclass of action '@(action.namespaced_type.name)'."""
 
-    _TYPE_SUPPORT = None
+    _TYPE_SUPPORT: typing.ClassVar[typing.Optional[PyCapsule]] = None
 
     @@classmethod
-    def __import_type_support__(cls):
+    def __import_type_support__(cls) -> None:
         try:
             from rosidl_generator_py import import_type_support
             module = import_type_support('@(package_name)')
@@ -92,5 +102,6 @@ class @(action.namespaced_type.name)(metaclass=Metaclass_@(action.namespaced_typ
         # The generic message for get the status of a goal.
         from action_msgs.msg._goal_status_array import GoalStatusArray as GoalStatusMessage
 
-    def __init__(self):
+    # type ignore below fixed in mypy 1.0+ see mypy#10342
+    def __init__(self) -> typing.NoReturn:  # type: ignore
         raise NotImplementedError('Action classes can not be instantiated')

rosidl_generator_py/resource/_action.py.em

@@ -2,11 +2,15 @@
 # with input from @(package_name):@(interface_path)
 # generated code does not contain a copyright notice
 
+from __future__ import annotations
+
+import collections.abc
+from os import getenv
+import typing
+
 # This is being done at the module level and not on the instance level to avoid looking
 # for the same variable multiple times on each instance. This variable is not supposed to
 # change during runtime so it makes sense to only look for it once.
-from os import getenv
-
 ros_python_check_fields = getenv('ROS_PYTHON_CHECK_FIELDS', default='')
 @
 @#######################################################################
@@ -19,6 +23,7 @@ ros_python_check_fields = getenv('ROS_PYTHON_CHECK_FIELDS', default='')
 @#######################################################################
 @{
 import_statements = set()
+type_annotations_import_statements = set()
 }@
 @
 @#######################################################################
@@ -32,7 +37,8 @@ from rosidl_parser.definition import Message
 TEMPLATE(
     '_msg.py.em',
     package_name=package_name, interface_path=interface_path, message=message,
-    import_statements=import_statements)
+    import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 }@
 @[end for]@
 @
@@ -47,7 +53,8 @@ from rosidl_parser.definition import Service
 TEMPLATE(
     '_srv.py.em',
     package_name=package_name, interface_path=interface_path, service=service,
-    import_statements=import_statements)
+    import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 }@
 @[end for]@
 @
@@ -62,6 +69,7 @@ from rosidl_parser.definition import Action
 TEMPLATE(
     '_action.py.em',
     package_name=package_name, interface_path=interface_path, action=action,
-    import_statements=import_statements)
+    import_statements=import_statements,
+    type_annotations_import_statements=type_annotations_import_statements)
 }@
 @[end for]@