Exclude OpenAPI/JSON Schema extension fields (x-*)

[ahmetveburak]

I'm not sure if this approach meets the design. I had to proceed, and I found this solution.

Fixes: #2800

Summary by CodeRabbit

• Bug Fixes

  • Improved JSON Schema extras handling: vendor extension fields (x-*) are now ignored when detecting schema keywords, preventing unintended schema merging and preserving intended $ref semantics.

• Tests

  • Added a test to verify that vendor extension keys do not trigger schema merging, ensuring parsing continues to treat $ref-only schemas correctly.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

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📥 Commits

Reviewing files that changed from the base of the PR and between 53e7613 and aef5ac5.

📒 Files selected for processing (2)

• src/datamodel_code_generator/parser/jsonschema.py
• tests/parser/test_jsonschema.py

📝 Walkthrough

Walkthrough

Ignore OpenAPI/JSON Schema vendor extension keys (prefixed with x-) when deciding if a $ref also contains schema-affecting keywords; has_ref_with_schema_keywords now filters out metadata-only keys and x-* extras from obj.extras before checking for schema keywords. (27 words)

Changes

Cohort / File(s)	Summary
Schema detection logic src/datamodel_code_generator/parser/jsonschema.py	Update has_ref_with_schema_keywords to exclude metadata-only keys and vendor extension keys (x-*) from obj.extras before evaluating presence of schema-affecting keywords.
Tests tests/parser/test_jsonschema.py	Add test_has_ref_with_schema_keywords_extras_with_extension_keys() asserting that extras containing only x-* extension keys do not trigger schema merging for a $ref.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• Pass schema extensions to templates #2790 — Also touches handling of x-* extension keys in jsonschema.py.

Poem

🐇
I nibbled extras, tossed the x- away,
Kept refs lean for a brighter day.
No needless merges, no looping fright,
I hopped along, the schema’s light.

Pre-merge checks and finishing touches

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title directly and clearly describes the main change: excluding OpenAPI/JSON Schema extension fields with the x-* prefix, which aligns with the core objective of fixing the recursion issue.
Linked Issues check	✅ Passed	The code changes properly address issue #2800 by filtering out x-* extension fields in has_ref_with_schema_keywords to prevent recursion, and the added test validates this behavior.
Out of Scope Changes check	✅ Passed	All changes are directly related to the linked issue: the code modification filters x-* extensions, and the test validates this filtering behavior.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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Actionable comments posted: 1

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 8c7550c and 43eb240.

📒 Files selected for processing (2)

• src/datamodel_code_generator/parser/jsonschema.py
• tests/parser/test_jsonschema.py

🧰 Additional context used

🧬 Code graph analysis (2)

src/datamodel_code_generator/parser/jsonschema.py (1)

src/datamodel_code_generator/util.py (1)

• get_fields_set (208-212)

tests/parser/test_jsonschema.py (1)

src/datamodel_code_generator/parser/jsonschema.py (3)

• JsonSchemaObject (202-472)
• parse_obj (3121-3162)
• has_ref_with_schema_keywords (453-472)

🔇 Additional comments (1)

src/datamodel_code_generator/parser/jsonschema.py (1)

453-472: LGTM! Clear fix for recursion issue with OpenAPI extension fields.

The implementation correctly filters out OpenAPI/JSON Schema extension fields (x-*) when determining if a schema has $ref combined with schema-affecting keywords. This prevents unnecessary schema merging that was causing recursion on large schemas with many extension fields.

The docstring update clearly explains the rationale, and the filter logic not k.startswith("x-") is efficient and aligns with the OpenAPI specification requirement that extension fields use lowercase "x-" prefix.

[codspeed-hq]

CodSpeed Performance Report

Merging #2801 will not alter performance

_{Comparing ahmetveburak:fix/exclude-extension-fields (aef5ac5) with main (9dc9dd4)}

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

Summary

✅ 11 untouched
⏩ 98 skipped¹

Footnotes

1. 98 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[koxudaxi]

@ahmetveburak
Thank you for creating the PR.
Can you fix the CI errors?
I expect this.

# tests/parser/test_jsonschema.py:925
- obj = JsonSchemaObject.parse_obj({
+ obj = model_validate(
+     JsonSchemaObject,
+     {
          "$ref": "#/$defs/Base",
          "deprecated": False,
          "x-internalAPI": False,
          "x-custom-field": "value",
-     })
+     },
+ )

[ilovelinux]

I'm not sure to understand how this PR affects current behavior and how it fixes the issue. A rationale is missing.

Also see #2800 (comment). Maybe this is a workaround for just that case? Maybe RecursionLimit may still be hit but this edit keep recursion under the limit for this particular case?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.37%. Comparing base (9dc9dd4) to head (aef5ac5).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2801   +/-   ##
=======================================
  Coverage   99.37%   99.37%           
=======================================
  Files          92       92           
  Lines       16040    16046    +6     
  Branches     1893     1893           
=======================================
+ Hits        15939    15945    +6     
  Misses         52       52           
  Partials       49       49           

Flag	Coverage Δ
unittests	99.37% <100.00%> (+<0.01%)	⬆️

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[Nekidev]

I tried this to get moving and the issue didn't go away when using the fixed branch:

[koxudaxi]

@Nekidev Can you provide the input schema? I want to test it.

[Nekidev]

@koxudaxi https://github.com/Nekidev/paddle-py/blob/main/openapi.yml

[Nekidev]

My temporary fix was to install the library as a library and import it from a script where I had previously set the recursion limit to 5000. It works, but it's not the best solution and neither is it a one-size-fits-all solution. The same repository has a generate.py file with it.

[koxudaxi]

@Nekidev
Thank you for reporting the issue. I believe the loop bug had a different cause. I've fixed it.
#2852

[Nekidev]

That's great! You're welcome.

[github-actions]

🎉 Released in 0.51.0

This PR is now available in the latest release. See the release notes for details.