Add comprehensive tests for cuddApa.c (83.3% coverage)

[Copilot]

Added test coverage for the Arbitrary Precision Arithmetic (APA) module. Coverage increased from 17.3% to 83.3%.

Changes

• 29 test cases covering all exported APA functions:

  • Arithmetic: Cudd_ApaAdd, Cudd_ApaSubtract, Cudd_ApaShortDivision, Cudd_ApaIntDivision, Cudd_ApaShiftRight
  • Comparison: Cudd_ApaCompare, Cudd_ApaCompareRatios
  • Output: Cudd_ApaPrintHex, Cudd_ApaPrintDecimal, Cudd_ApaStringDecimal, Cudd_ApaPrintExponential
  • Minterm: Cudd_ApaCountMinterm, Cudd_ApaPrintMinterm, Cudd_ApaPrintMintermExp, Cudd_ApaPrintDensity

• Edge cases tested: carry propagation, borrow handling, multi-digit arithmetic, rounding in exponential printing, complemented BDD nodes

Coverage Gap (90% not achievable)

The remaining 53 uncovered lines are defensive error handling:

• Memory allocation failures (~22 lines)
• fprintf EOF returns (~10 lines)
• Dead code in Cudd_ApaPrintExponential (1 line)
• Internal recursive function error paths (~20 lines)

These require mocking infrastructure not available in Catch2.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• esm.ubuntu.com
  • Triggering command: /usr/lib/apt/methods/https /usr/lib/apt/methods/https (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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

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