Fix DataType deepcopy infinite recursion with circular references by koxudaxi · Pull Request #2852 · koxudaxi/datamodel-code-generator

koxudaxi · 2025-12-29T04:36:12Z

Summary by CodeRabbit

New Features
- Added deep copy capability for data types and configuration objects, enabling creation of independent copies with automatic circular reference handling.
Tests
- Expanded test coverage for deep copy functionality, including circular references, nested structures, memoization, and edge cases.

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coderabbitai · 2025-12-29T04:36:17Z

📝 Walkthrough

Walkthrough

Adds __deepcopy__ methods to DataType and Config classes to enable safe deep copying with circular reference handling. Includes comprehensive test coverage for various deepcopy scenarios including nested structures, memoization behavior, and circular parent-child relationships.

Changes

Cohort / File(s)	Summary
DataType and Config deepcopy implementation `src/datamodel_code_generator/types.py`	Added `__deepcopy__` methods to DataType and Config classes with memo-based circular reference tracking, shallow field-wise construction, and recursive deepcopy of non-excluded fields (parent/children excluded).
Deepcopy test coverage `tests/test_types.py`	Added 5 test functions covering circular reference handling, nested DataType preservation, memoization cache behavior, and None memo edge cases.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

🐰 Deep copies crafted with care and grace,
Circular references know their place!
Memo tracks all through the rabbit's warren,
DataTypes cloned without a worry or sorrow'n! 🥕

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: adding deepcopy support with circular reference handling to DataType.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

📝 Generate docstrings

🧪 Generate unit tests (beta)

Create PR with unit tests
Post copyable unit tests in a comment
Commit unit tests in branch fix/datatype-deepcopy-recursion

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github-actions · 2025-12-29T04:37:00Z

📚 Docs Preview: https://pr-2852.datamodel-code-generator.pages.dev

codspeed-hq · 2025-12-29T04:39:22Z

CodSpeed Performance Report

Merging #2852 will not alter performance

_{Comparing fix/datatype-deepcopy-recursion (d039eb7) with main (055f8ed)}

⚠️

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Summary

✅ 11 untouched
⏩ 98 skipped¹

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 · 2025-12-29T04:39:35Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.50%. Comparing base (16f27ef) to head (d039eb7).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main    #2852    +/-   ##
========================================
  Coverage   99.50%   99.50%            
========================================
  Files          90       90            
  Lines       14489    14689   +200     
  Branches     1736     1754    +18     
========================================
+ Hits        14417    14617   +200     
  Misses         37       37            
  Partials       35       35

Flag	Coverage Δ
unittests	`99.50% <100.00%> (+<0.01%)`	⬆️

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coderabbitai

Actionable comments posted: 0

🧹 Nitpick comments (1)

tests/test_types.py (1)
243-274: Good coverage for edge cases.

Both tests appropriately cover:

memo=None initialization (line 252)

Memo cache hit returning the same object (lines 269-274)

The # noqa comments are flagged by static analysis as unnecessary for the current Ruff configuration. You may optionally remove them for cleaner code, though keeping them is harmless if you want to guard against other linters.
Optional: Remove unused noqa directives
-    from datamodel_code_generator.model.base import DataModelFieldBase  # noqa: F401
+    from datamodel_code_generator.model.base import DataModelFieldBase
Apply similar changes to lines 166, 190, 217, 246, 262, and remove # noqa: PLC2801 from lines 252, 269, 274.

📜 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 16f27ef and d039eb7.

📒 Files selected for processing (2)

src/datamodel_code_generator/types.py
tests/test_types.py

🧰 Additional context used

🧬 Code graph analysis (2)

src/datamodel_code_generator/types.py (1)

src/datamodel_code_generator/util.py (1)

is_pydantic_v2 (52-57)

tests/test_types.py (1)

src/datamodel_code_generator/types.py (1)

DataType (297-838)

🪛 Ruff (0.14.10)

tests/test_types.py

166-166: Unused noqa directive (non-enabled: F401)