fix(python-aiohttp, python-blueplanet, python-flask): map params iterate .items(); free-form params skip from_dict

KH
2d ago
+328-3

Two small template bugs in the Connexion-based Python server generators (python-aiohttp, python-blueplanet, python-flask), both reproduced with the released openapi-generator-cli 7.26.0.

1. python-aiohttp: map parameters iterate the dict's keys

python-aiohttp/controller.mustache renders map conversions as {k: ...(v) for k, v in {{paramName}}}, without .items(). At runtime this tries to unpack each key string into k, v, which fails with ValueError. The python-blueplanet and python-flask templates already use .items(). This PR adds .items(), and also guards optional map parameters with if {{paramName}} is not None:, since they default to None.

2. Free-form / any-type parameters call object.from_dict(...)

For a non-container parameter whose schema is free-form ({type: object} with no properties) or empty ({}), the type is plain object, and the templates emit x = object.from_dict(x) (python-flask), or x = .from_dict(x) (python-aiohttp and python-blueplanet, which fail to import with SyntaxError). object has no from_dict, so the handler fails at runtime.

AbstractPythonConnexionServerCodegen now marks parameters that are free-form or any-type and whose dataType is plain object with the vendor extension x-python-connexion-skip-from-dict. The templates skip the conversion for those parameters, so they receive the raw value. Parameters whose type is a model are not affected, including typeless composed models (allOf / oneOf refs), which are also any-type but carry a model dataType.

Tests and verification

  • New specs: src/test/resources/3_1/python/map-and-freeform-params.yaml and composed-query-params.yaml. New tests in AbstractPythonConnexionServerCodegenTest. They check that .items() and the None guard are emitted, that free-form and {} parameters get no from_dict, and that Composed.from_dict / OneOfM.from_dict / Pet.from_dict are still emitted for model parameters. Each test fails without its fix.
  • Python*Test, AbstractPython*Test: 164 tests, 0 failures. Samples for bin/configs/python-aiohttp*, python-blueplanet* and python-flask* regenerate with no changes.
  • Compared with 7.26.0 output: for composed-query-params.yaml, default_controller.py is identical in all three generators. For map-and-freeform-params.yaml, the python-aiohttp and python-blueplanet controllers no longer fail py_compile, and the python-flask object.from_dict lines are gone.
  • Called the generated python-aiohttp handler with real map and free-form values, and with the optional maps omitted. It returned 200.

Note on overlap

This touches the same {{^isContainer}}…{{^isPrimitiveType}} blocks of the three controller templates as #25352 and #25362. Whichever lands first, I'll rebase the others.

PR checklist

  • Read the contribution guidelines.
  • Run the following to build the project and update samples: 
    ./mvnw clean package || exit
./bin/generate-samples.sh ./bin/configs/*.yaml || exit
./bin/utils/export_docs_generators.sh || exit
    Ran the Python generator tests listed above and regenerated the samples for the three affected generators' configs. No sample changed. Generator options and docs are unchanged.
  • If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

cc @cbornet @tomplus @krjakbrjak @fa0311 (Python technical committee)

Parts of this change were drafted with AI coding assistants (Devin, Claude Code) and reviewed and verified by me.

🤖 Generated with Claude Code

Summary by cubic

Fixes two template bugs in the Python Connexion server generators (python-aiohttp, python-blueplanet, python-flask): map parameters now iterate dict.items(), and free-form or untyped object parameters no longer get deserialized via from_dict.

Bug Fixes

  • Adds .items() to map parameter comprehensions in python-aiohttp and guards optional maps with a None check.
  • Marks free-form and {} schema parameters (with plain object dataType) with the vendor extension x-python-connexion-skip-from-dict, so controllers receive raw values; model and composed model parameters remain unchanged.
  • Adds test specs and generator tests covering map, free-form, and composed model parameters, including maps with additionalProperties.