Refactor reflection-based white-box tests into public-contract tests

[ahmed-bhs]

Problem

Some unit tests are tightly coupled to private implementation details by invoking private methods through reflection.

Current hotspots

• tests/Unit/Collector/DoctrineDoctorDataCollectorTest.php
  • invokes private methods: filterQueriesByPaths, isQueryFromExcludedPaths
• tests/Unit/DependencyInjection/DoctrineDoctorExtensionTest.php
  • invokes private method: classNameToConfigKey

These tests are brittle: harmless internal refactors (renaming/moving private methods) can break tests even when public behavior is unchanged.

Why refactor

• Preserve refactorability of internals
• Keep tests focused on observable behavior
• Reduce maintenance cost and false failures

Proposed approach

1. Replace private-method reflection tests with public-contract tests wherever possible.
2. For complex pure logic currently hidden in private methods, extract dedicated collaborators and test them directly (without reflection), for example:
   • query path filtering logic from DoctrineDoctorDataCollector
   • analyzer config key formatting logic from DoctrineDoctorExtension
3. Keep DoctrineDoctorDataCollector / DoctrineDoctorExtension tests at integration-of-collaborators level (public API only).

Acceptance criteria

• No test uses reflection to invoke private methods in these areas.
• Equivalent behavior coverage is preserved or improved.
• Existing public behavior remains unchanged.
• Test suite remains green (phpunit, phpstan, ecs).

Notes

This issue is intentionally scoped to tests coupled to private methods. Other test quality improvements can be tracked separately.