fix: check join type when reusing joins in ConstraintTransformerJpaImpl

[javier-godoy]

Close #111

Summary by CodeRabbit

• Bug Fixes

  • Improved join detection logic in persistence queries to ensure joins are correctly matched and reused based on both attribute matching and join type compatibility.

• Tests

  • Added test coverage for complex filter scenarios involving null constraints combined with logical operators.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: ee6e6d31-8bc3-4f5e-8eaa-e531fa3dfd61

📥 Commits

Reviewing files that changed from the base of the PR and between fa635b5 and 8b83816.

📒 Files selected for processing (2)

• backend-core-data-impl/src/main/java/com/flowingcode/backendcore/dao/jpa/ConstraintTransformerJpaImpl.java
• backend-core-data-impl/src/test/java/com/flowingcode/backendcore/dao/jpa/JpaDaoSupportTest.java

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Walkthrough

This PR refines join reuse detection in ConstraintTransformerJpaImpl by adding an explicit join-type check. When reusing existing joins by attribute name, the code now verifies the join type matches currentJoinType. A test case validates that IS NULL constraints correctly exclude rows with absent associations when preceded by disjunction constraints on the same path.

Changes

Cohort / File(s)	Summary
Join Type Matching backend-core-data-impl/src/main/java/com/flowingcode/backendcore/dao/jpa/ConstraintTransformerJpaImpl.java	Updated join() helper to filter existing joins by both attribute name and join type, ensuring joins are only reused when types match. Prevents incorrect reuse of LEFT JOINs when INNER JOINs are needed.
IS NULL Constraint Test backend-core-data-impl/src/test/java/com/flowingcode/backendcore/dao/jpa/JpaDaoSupportTest.java	Added testIsNullConstraintAfterOrDoesNotMatchAbsentCity() to verify IS NULL constraints correctly exclude rows with absent associations after disjunction branches.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• feat: add OR operator to QuerySpec constraints #108: Prior PR that attempted to address join-type mismatch detection but was revised; this PR implements the refined approach with explicit join-type filtering in the reuse logic.

Suggested reviewers

• mlopezFC

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The pull request title accurately summarizes the main change: fixing join type checking when reusing joins in ConstraintTransformerJpaImpl.
Linked Issues check	✅ Passed	The pull request directly addresses issue #111 by implementing the proposed fix: checking join type when reusing joins to prevent IS NULL constraints from incorrectly matching absent associations.
Out of Scope Changes check	✅ Passed	All changes are scoped to fixing the join type reuse issue and adding a test case that validates the fix for issue #111; no unrelated modifications detected.

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✨ Finishing Touches

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🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-111

📝 Coding Plan

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud