Add comprehensive tests for cuddSymmetry.c targeting 90% coverage

[Copilot]

• Analyze current test coverage for src/cuddSymmetry.c (was at 2.5%)
• Understand the cuddSymmetry.c source code structure and functions
• Build and run existing test suite to verify current state
• Write comprehensive tests achieving 85.3% coverage targeting:
  • Cudd_SymmProfile function (with/without symmetries, partial ranges)
  • cuddSymmCheck function (symmetric pairs, non-symmetric, isolated projections, complemented edges)
  • cuddSymmSifting function (via CUDD_REORDER_SYMM_SIFT with various limits)
  • cuddSymmSiftingConv function (via CUDD_REORDER_SYMM_SIFT_CONV)
  • Static helper functions (ddSymmSiftingAux, ddSymmSiftingUp/Down, ddSymmGroupMove, ddSymmGroupMoveBackward, ddSymmSiftingBackward, ddSymmSummary)
  • Termination callback and time limit tests
  • Cudd_VarsAreSymmetric API tests
• Run coverage report: 85.3% line coverage (551/646 lines)
• Run code review and address feedback:
  • Updated documentation to reflect actual 85% coverage
  • Added meaningful assertion comparing nodesBefore and nodesAfter
  • Changed termination callback to conditionally terminate after iterations
  • Increased time limit from 1ms to 50ms for reliability
• Run security checks (no issues found)

Note: The remaining ~15% uncovered code consists primarily of out-of-memory error handling paths that are difficult to trigger in unit tests without mocking memory allocation.

Original prompt

Complete test cases for src/cuddSymmetry.c and target 90% coverage for the source file.

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[doganulus]

@copilot Implement test cases

[Copilot]

@copilot Implement test cases

Implemented comprehensive test cases for cuddSymmetry.c in commits e39057f and 1ad14cd. The tests achieve 85.3% line coverage (551/646 lines) and cover all 13 functions in the module including:

• Cudd_SymmProfile, cuddSymmCheck, cuddSymmSifting, cuddSymmSiftingConv
• Static helpers: ddSymmSiftingAux, ddSymmSiftingUp/Down, ddSymmGroupMove, ddSymmGroupMoveBackward, ddSymmSiftingBackward, ddSymmSummary
• Termination callbacks, time limits, and edge cases

The remaining ~15% uncovered code consists primarily of out-of-memory error handling paths.