Add unit tests for update_cicaid_pins.py version parsing and pin file manipulation logic #4

Add unit tests for update_cicaid_pins.py version parsing and pin file manipulation logic

What

Add unit tests for the update_cicaid_pins.py script, specifically covering:

• _parse_version function — edge cases like 1.0 vs 1.0.0, version normalization, and invalid input handling
• _versions_equal function — comparison logic for semantically equivalent versions
• Pin file manipulation logic — reading, updating, and writing pin entries

Why

The script has complex version parsing and comparison logic that handles edge cases (e.g., 1.0 vs 1.0.0). Currently there is no test coverage, so regressions in version handling could silently break pin updates. The script is part of the CI/CD infrastructure, making correctness critical — a bug could cause incorrect dependency pins or failed update runs.

How

1. Create a test file (e.g., tests/test_update_cicaid_pins.py) alongside the script
2. Use Python's built-in unittest framework (no new dependencies needed, consistent with the script's stdlib-only approach)
3. Test cases should include:
   • _parse_version: valid versions with different formats (1.0, 1.0.0, 1.0.0+meta), invalid versions, empty strings
   • _versions_equal: comparing 1.0 vs 1.0.0 (should be equal), 1.0.0 vs 1.0.1 (not equal), versions with build metadata
   • Pin file manipulation: create a temp pin file, add/update/remove entries, verify file contents
4. Use tempfile for file manipulation tests to avoid polluting the repo
5. Add a test runner step to the CI workflow if not already present

Files Affected

• update_cicaid_pins.py (test target)
• tests/test_update_cicaid_pins.py (new file)
• .github/workflows/update-cicaid.yml (add test step, if applicable)

Constraints

• Must not introduce new Python dependencies (stdlib only)
• Must not change the behavior of update_cicaid_pins.py — tests should validate existing logic, not require refactoring
• Test file should be discoverable by standard test runners (pytest or unittest)
• Out of scope: refactoring the script for testability, adding tests for shell scripts, or addressing other review findings

LLM Tier

Sonnet — requires moderate design judgment for test case selection and file manipulation test setup, but is a contained, single-file testing task.

Success Looks Like

• All test cases pass when run locally and in CI
• Test coverage includes at least:
  • _parse_version with 1.0, 1.0.0, 1.0.0+meta, and invalid inputs
  • _versions_equal with equivalent and non-equivalent version pairs
  • Pin file add/update/remove operations with verification of file contents
• Tests run as part of the existing CI workflow (or a new test step added to update-cicaid.yml)

Failure Looks Like

• Tests fail when run against the current update_cicaid_pins.py (indicating the tests are wrong or the script has bugs that need fixing)
• Tests pass but don't actually exercise the edge cases (e.g., only testing happy paths)
• New dependencies introduced despite the constraint
• Test file not discoverable by the CI test runner

Follow-up from AI review of PR #3.

Implementation notes

FILES: tests/test_update_cicaid_pins.py, .github/workflows/update-cicaid.yml
DONE: Unit tests created for _parse_version, _versions_equal, and pin file manipulation in update_cicaid_pins.py, with all tests passing locally and a test step added to the CI workflow.