Improve readability when printing type of classes in error messages

[ijnek]

Description

In many places, error messages printed types in a verbose format like '<class 'str'>'. This PR simplifies that by displaying just the type name (e.g. 'str').

For example, given this invalid XML:

<?xml version="1.0"?>
<launch>
  <node />
</launch>

The previous error output was:

- AttributeError: Attribute 'exec' of type '<class 'str'>' not found in Entity 'node'

With this change, it becomes:

- AttributeError: Attribute 'exec' of type 'str' not found in Entity 'node'

Did you use Generative AI?

No

[fujitatomoya]

i think this is more user-friendly error message, lgtm with green CI.

[fujitatomoya]

Pulls: #887
Gist: https://gist.githubusercontent.com/fujitatomoya/67fc4c3c4a310ad34e68e81555fc9f66/raw/8fe810c7c70d60d3809b8a34e1e046b731a4255a/ros2.repos
BUILD args: --packages-above-and-dependencies launch launch_testing launch_yaml launch_xml
TEST args: --packages-above launch launch_testing launch_yaml launch_xml
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/16219

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[ahcorde]

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[christophebedard]

flake8 is complaining about double quotes: https://build.ros2.org/job/Rpr__launch__ubuntu_noble_amd64/284/testReport/junit/launch.test/test_flake8/test_flake8/

  ./launch/utilities/type_utils.py:317:69: Q000 Double quotes found but single quotes preferred
  ./launch/utilities/type_utils.py:463:66: Q000 Double quotes found but single quotes preferred

Also, I think ci.ros2.org is broken for unrelated reasons: ros2/ros2#1699

[ahcorde]

Pulls: #887
Gist: https://gist.githubusercontent.com/ahcorde/b622eab172b02dc1d71d4af6d7ac919f/raw/fe9a0f65ec0db0411bf7bad0526f314b88409961/ros2.repos
BUILD args: --packages-above-and-dependencies launch launch_testing launch_xml launch_yaml
TEST args: --packages-above launch launch_testing launch_xml launch_yaml
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/16254

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[christophebedard]

Unfortunately, mypy is still complaining 😅

• https://build.ros2.org/job/Rpr__launch__ubuntu_noble_amd64/286/consoleFull#console-section-59
• https://ci.ros2.org/job/ci_linux-aarch64/18064/consoleFull#console-section-737

[ahcorde]

Pulls: #887
Gist: https://gist.githubusercontent.com/ahcorde/c98b030f240e9481de3c7ef428aa8122/raw/fe9a0f65ec0db0411bf7bad0526f314b88409961/ros2.repos
BUILD args: --packages-above-and-dependencies launch launch_testing launch_xml launch_yaml
TEST args: --packages-above launch launch_testing launch_xml launch_yaml
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/16265

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[christophebedard]

it's not reflected in the type annotation above, but data_type can be None apparently here and below :/ see the documentation for this method in the base class:

launch/launch/launch/frontend/entity.py

Line 89 in 6854fae

`data_type = None` will result in yaml parsing of the attribute value as a string.

1. https://ci.ros2.org/job/ci_linux/24014/testReport/junit/test_launch_ros.test.test_launch_ros.frontend/test_component_container/test_launch_component_container_xml/
2. https://ci.ros2.org/job/ci_linux/24014/testReport/junit/test_launch_ros.test.test_launch_ros.frontend/test_node_frontend/test_launch_frontend_xml/

I'll open an issue to fix the type annotation.

[christophebedard]

I'll open an issue to fix the type annotation.

#888

[christophebedard]

And unfortunately RHEL fails for a different reason here and in some other places where the variable can be a typing class like typing.List:

1. https://ci.ros2.org/job/ci_linux-rhel/3416/testReport/junit/launch_xml.test.launch_xml/test_arg/test_arg_wrong_attribute/
2. https://ci.ros2.org/job/ci_linux-rhel/3416/testReport/junit/launch.test.launch.utilities/test_type_utils/test_extract_type/
3. https://ci.ros2.org/job/ci_linux-rhel/3416/testReport/junit/launch.test.launch.utilities/test_type_utils/test_normalize_typed_substitution/

I think it's because it's using an older Python version (3.9) in which typing classes like List don't have a __name__: python/cpython#86495. This was fixed in >=3.10: python/cpython#27237.

So this would require some workaround for those locations

[ahcorde]

@ijnek do you mind to take a look ?

[InvincibleRMC]

I think it's because it's using an older Python version (3.9) in which typing classes like List don't have a __name__: python/cpython#86495. This was fixed in >=3.10: python/cpython#27237.

Since the minimum version is 3.9 you can probably replace the typing versions with builtins like list which I believe should have __name__

[ahcorde]

friendly ping @ijnek