Use absolute imports for generated local type support

[Lidang-Jiang]

Summary

Fixes #257.

• Generate absolute module imports for namespaced message field types, e.g. import builtin_interfaces.msg.
• Refer to namespaced types by their fully qualified module path in type support imports, default construction, annotations, and check_fields assertions.
• Add template-level regression coverage for scalar, fixed-size array, and unbounded sequence fields using builtin_interfaces/Duration, without adding a package-level test dependency on builtin_interfaces.

Did you use Generative AI?

Yes. I used OpenAI Codex (GPT-5) to help investigate the issue, prepare the code and test changes, and draft/update this PR description. I reviewed the changes and ran the local tests listed below before opening the PR.

Before / After

Before

Command:

git show upstream/rolling:rosidl_generator_py/resource/_msg.py.em | sed -n '178,207p'

Output:

        type_ = type_.value_type
    if isinstance(type_, NamespacedType):
        if (
            type_.name.endswith(SERVICE_RESPONSE_MESSAGE_SUFFIX) or
            type_.name.endswith(SERVICE_REQUEST_MESSAGE_SUFFIX)
        ):
            continue
        if (
            type_.name.endswith(ACTION_GOAL_SUFFIX) or
            type_.name.endswith(ACTION_RESULT_SUFFIX) or
            type_.name.endswith(ACTION_FEEDBACK_SUFFIX)
        ):
            action_name, suffix = type_.name.rsplit('_', 1)
            typename = (*type_.namespaces, action_name, action_name + '.' + suffix)
        else:
            typename = (*type_.namespaces, type_.name, type_.name)
        importable_typesupports.add(typename)
}@
@[for typename in sorted(importable_typesupports)]@

            from @('.'.join(typename[:-2])) import @(typename[-2])
            if @(typename[-1])._TYPE_SUPPORT is None:
                @(typename[-1]).__import_type_support__()
@[end for]@

After

Command:

rg -n "builtin_interfaces\\.msg|from builtin_interfaces\\.msg" \
  build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py \
  build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py

Output:

build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:27:    import builtin_interfaces.msg  # noqa: E402, I100, I201, I300
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:72:            import builtin_interfaces.msg
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:73:            if builtin_interfaces.msg.Duration._TYPE_SUPPORT is None:
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:74:                builtin_interfaces.msg.Duration.__import_type_support__()
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:107:                 array_data: typing.Optional[collections.abc.Sequence[builtin_interfaces.msg.Duration]] = None,  # noqa: E501
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:108:                 sequence_data: typing.Optional[collections.abc.Sequence[builtin_interfaces.msg.Duration]] = None,  # noqa: E501
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:114:        import builtin_interfaces.msg
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:115:        self.array_data = array_data if array_data is not None else [builtin_interfaces.msg.Duration() for x in range(2)]
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:162:    def array_data(self) -> typing.Annotated[typing.Any, list[builtin_interfaces.msg.Duration]]:   # typing.Annotated can be remove after mypy 1.16+ see mypy#3004
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:167:    def array_data(self, value: collections.abc.Sequence[builtin_interfaces.msg.Duration]) -> None:
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:174:        import builtin_interfaces.msg
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:186:                     all(isinstance(v, builtin_interfaces.msg.Duration) for v in value) and
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:188:                    "The 'array_data' field must be sequence with length 2 and each value of type 'builtin_interfaces.msg.Duration'"
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:196:    def sequence_data(self) -> typing.Annotated[typing.Any, list[builtin_interfaces.msg.Duration]]:   # typing.Annotated can be remove after mypy 1.16+ see mypy#3004
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:201:    def sequence_data(self, value: collections.abc.Sequence[builtin_interfaces.msg.Duration]) -> None:
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:208:        import builtin_interfaces.msg
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:219:                     all(isinstance(v, builtin_interfaces.msg.Duration) for v in value) and
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration_array_sequence.py:221:                    "The 'sequence_data' field must be sequence and each value of type 'builtin_interfaces.msg.Duration'"
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:27:    import builtin_interfaces.msg  # noqa: E402, I100, I201, I300
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:72:            import builtin_interfaces.msg
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:73:            if builtin_interfaces.msg.Duration._TYPE_SUPPORT is None:
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:74:                builtin_interfaces.msg.Duration.__import_type_support__()
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:104:                 data: typing.Optional[builtin_interfaces.msg.Duration] = None,  # noqa: E501
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:110:        import builtin_interfaces.msg
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:111:        self.data = data if data is not None else builtin_interfaces.msg.Duration()
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:155:    def data(self) -> builtin_interfaces.msg.Duration:
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:160:    def data(self, value: builtin_interfaces.msg.Duration) -> None:
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:161:        import builtin_interfaces.msg
build_pr/rosidl_generator_py/rosidl_generator_py/rosidl_generator_py/msg/_duration.py:168:                    isinstance(value, builtin_interfaces.msg.Duration), \

Tests

Command:

PYTHONPATH=rosidl_generator_py:$WORKSPACE/rosidl/rosidl_parser:$WORKSPACE/rosidl/rosidl_pycommon python3 -m pytest rosidl_generator_py/test/test_template_imports.py -q

Output:

..                                                                       [100%]
2 passed in 0.12s

Command:

python3 -m flake8 rosidl_generator_py/test/test_template_imports.py
git diff --check

Output:

<no output>

[christophebedard]

@Lidang-Jiang did you use AI to write all/some of this code or open this PR?

[Lidang-Jiang]

Thanks for checking. Yes, I used OpenAI Codex (GPT-5) to help investigate the issue, prepare the code and test changes, and draft/update this PR description. I updated the PR body with a Generative AI disclosure section as well.

[christophebedard]

@InvincibleRMC could you review this?

[InvincibleRMC]

I will run CI to double check. But I'm pretty sure this won't work since this would cause a circular package order. We might need to make another pr before this splitting the tests into there own rosidl_generator_py_tests or something to avoid this.

[InvincibleRMC]

Yeah CI complains about being unable to topologically order the package after adding builtin_interfaces.

[Lidang-Jiang]

Good catch, fixed in 3dd9104. I removed the builtin_interfaces test dependency and moved the regression coverage to a template-level pytest so this no longer affects package ordering.

[Lidang-Jiang]

Confirmed, fixed in 3dd9104 by removing the generated builtin_interfaces test interfaces and the CMake/package.xml dependency that caused the topological cycle.

[Lidang-Jiang]

Also addressed in 3dd9104: the package-order failure is gone because the PR no longer adds builtin_interfaces to rosidl_generator_py CMake/package test dependencies.

[InvincibleRMC]

Pulls: #261
Gist: https://gist.githubusercontent.com/InvincibleRMC/958b7530d78835ed1ae7c544e9336c58/raw/bb0c723b0335bf0d3247b31f5bfa66a8298a8111/ros2.repos
BUILD args: --continue-on-error --packages-above-and-dependencies rosidl_generator_py
TEST args: --packages-above rosidl_generator_py
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/19266

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