Use semantic None checks in templates

[koxudaxi]

Summary by CodeRabbit

• Tests
  • Added comprehensive test coverage for strip-default-none behavior with root models and schema ID templates.
  • Expanded test coverage for custom template support with semantic configurations.
  • Added test cases for multiple Pydantic model types including BaseModel and dataclass variants across different versions.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Run ID: 14fd89bc-c1cf-4b22-b367-d7fda67ac188

📥 Commits

Reviewing files that changed from the base of the PR and between ea7a3aa and f968fdc.

⛔ Files ignored due to path filters (8)

• src/datamodel_code_generator/model/template/dataclass.jinja2 is excluded by none and included by none
• src/datamodel_code_generator/model/template/pydantic_v2/BaseModel.jinja2 is excluded by none and included by none
• src/datamodel_code_generator/model/template/pydantic_v2/RootModel.jinja2 is excluded by none and included by none
• src/datamodel_code_generator/model/template/pydantic_v2/dataclass.jinja2 is excluded by none and included by none
• tests/data/jsonschema/strip_default_none_root_string_none.json is excluded by !tests/data/**/*.json and included by none
• tests/data/jsonschema/strip_default_none_semantic.json is excluded by !tests/data/**/*.json and included by none
• tests/data/templates_extensions/pydantic_v2/BaseModel.jinja2 is excluded by none and included by none
• tests/data/templates_schema_id/pydantic_v2/BaseModel.jinja2 is excluded by none and included by none

📒 Files selected for processing (7)

• tests/data/expected/main/jsonschema/strip_default_none_root_string_none.py
• tests/data/expected/main/jsonschema/strip_default_none_semantic_schema_id.py
• tests/data/expected/main/openapi/strip_default_none_semantic_custom_template_extensions.py
• tests/data/expected/main/openapi/strip_default_none_semantic_pydantic_v2.py
• tests/data/expected/main/openapi/strip_default_none_semantic_pydantic_v2_dataclass.py
• tests/main/jsonschema/test_main_jsonschema.py
• tests/main/openapi/test_main_openapi.py

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📝 Walkthrough

Walkthrough

Adds five expected output fixture files and four new or extended test cases for the --strip-default-none flag. The fixtures cover pydantic v2 BaseModel, dataclass, RootModel, and custom-template scenarios in both JSON Schema and OpenAPI contexts. Tests assert that string 'None' defaults are preserved while null defaults are stripped.

Changes

strip-default-none test fixtures and regression tests

Layer / File(s)	Summary
Expected output fixture files tests/data/expected/main/jsonschema/strip_default_none_root_string_none.py, tests/data/expected/main/jsonschema/strip_default_none_semantic_schema_id.py, tests/data/expected/main/openapi/strip_default_none_semantic_pydantic_v2.py, tests/data/expected/main/openapi/strip_default_none_semantic_pydantic_v2_dataclass.py, tests/data/expected/main/openapi/strip_default_none_semantic_custom_template_extensions.py	Five new canonical fixture files defining expected generated models: a RootModel[str] with root defaulting to 'None'; a BaseModel with __path__ and three optional fields; pydantic v2 BaseModel and dataclass variants of SemanticNoneModel; and a custom-template extensions variant — all retaining string 'None' defaults while stripping actual null defaults.
Regression and E2E tests tests/main/jsonschema/test_main_jsonschema.py, tests/main/openapi/test_main_openapi.py	Adds two new jsonschema tests (root model string-None preservation; schema_id custom template with cache isolation) and extends the openapi parametrize table with pydantic_v2.BaseModel and pydantic_v2.dataclass entries, plus a new isolated-cache custom-template test.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• koxudaxi/datamodel-code-generator#3479: Introduces should_strip_default_none() and the semantic rendering logic that the new fixtures and tests directly validate.
• koxudaxi/datamodel-code-generator#3476: Changes how "None" is rendered in Field(...) defaults, which the new stringNoneDefault = 'None' fixtures are designed to assert against.
• koxudaxi/datamodel-code-generator#3424: Updates tests/main/conftest.py with the cache-context helpers that the new isolated-cache tests depend on.

Poem

🐇 Hopping through the schemas, checking every None,
A string that says 'None' — not null, just a pun!
The fixtures are planted, the asserts all gleam,
Default stripping logic now lives in a dream.
With pydantic v2 and dataclass in tow,
The rabbit stamps "LGTM" and off the tests go! 🥕

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Use semantic None checks in templates' directly describes the main objective of the PR, which is to implement semantic None default value checking within Jinja templates for code generation.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/template-none-default-checks

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[github-actions]

📚 Docs Preview: https://pr-3480.datamodel-code-generator.pages.dev

[codspeed-hq]

Merging this PR will not alter performance

⚠️ 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.

✅ 11 untouched benchmarks
⏩ 98 skipped benchmarks¹

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_{Comparing fix/template-none-default-checks (f968fdc) with main (ea7a3aa)}

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. ↩

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (ea7a3aa) to head (f968fdc).

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #3480   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          151       151           
  Lines        32498     32510   +12     
  Branches      3783      3783           
=========================================
+ Hits         32498     32510   +12     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

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