Add regression-guard tests for validation steps, CMake parser, and ro…

[Joschi3]

Why

PRs #21 and #22 added significant new code without matching unit tests.
Several logical branches had no test pinning their behaviour — they worked,
but nothing would catch a future refactor that quietly inverts a condition,
drops a warning, or reorders a sort. This PR closes those gaps. The goal is
regression protection, not coverage-number theatre.

What's tested now that wasn't before

Validation step branches

• CMakeComparisonStep: missing CMakeLists.txt, strict-vs-non-strict
  unresolved-dep reporting, evaluate_conditions=False formatter fallback.
• RosdepCheckStep: all three early-return paths.
• BuildTypeExportStep: check-only missing/wrong type, no-auto-fill
  critical error, auto-fill success path.
• PackageXmlValidator: compare_with_cmake && !check_rosdeps guard,
  malformed-XML continuation.

Parsing & resolution logic

• cmake_parsers: find_package(... QUIET) without REQUIRED is skipped;
  resolve_for_each correctly expands foreach(... IN LISTS ...) blocks.
• rosdep_validator.search_rosdep_candidates: the 4-tier sort order,
  length tiebreaks, and the 5-result cap.

Filesystem / workspace edge cases

• TOML files outside a launch/ directory are skipped during launch-dep
  discovery.
• workspace.get_pkgs_in_wrs pkg_dir is None fallback.
• verify_rosdep_mapping: YAML load failure and per-key ResolutionError
  paths.
• resolve_indentation empty-root / tail=None / no-newline fallbacks.

162 → 194 tests, all passing. No production code changes.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[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