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name: code-sentinel description: Use when code pattern tests fail - fixes recurring anti-patterns with documented root causes and verification

Code Sentinel

Fix recurring anti-patterns detected by automated code pattern tests.

You MUST use this skill when code pattern tests fail. Even if the fix looks obvious. The anti-pattern files document WHY patterns fail, not just HOW to fix them.

Workflow

1. Run your project's code pattern tests (e.g., pytest tests/test_code_patterns.py -v)
2. For each failing test, read the anti-pattern file (see index below)
3. Understand the root cause (not just the fix)
4. Apply the documented fix
5. Verify tests pass

Anti-Pattern Index

CI/Workflow Anti-Patterns

Issues that occur in GitHub Actions workflows and CI pipelines.

Build/Packaging Anti-Patterns

Issues with PyInstaller bundling, version generation, and cross-platform builds.

Application/Runtime Anti-Patterns

Issues in application code that cause runtime failures or unexpected behavior.

Quick Reference: Test-to-File Mapping

Copytest_no_heredocs_in_github_actions       → ci-workflow/yaml-heredoc-indentation.md
test_no_grep_exit_code_echo_pattern      → ci-workflow/grep-exit-code-echo-fallback.md
test_git_operations_with_staging         → ci-workflow/git-pull-without-autostash.md
test_workflow_dispatch_has_actions_permission → ci-workflow/gh-workflow-run-permissions.md
test_venv_activation_uses_linux_path     → ci-workflow/windows-venv-path-on-linux.md
test_pyinstaller_hidden_imports          → build-packaging/pyinstaller-missing-hidden-imports.md
test_sibling_imports_use_relative_syntax → build-packaging/sibling-absolute-import-bundling.md
test_spec_uses_forward_slashes           → build-packaging/windows-backslash-in-spec.md
test_deterministic_file_sorting          → application-runtime/sort-without-tiebreaker.md
test_no_fixed_window_geometry            → application-runtime/fixed-window-geometry.md

Common Mistakes

Adding New Anti-Patterns

When you discover a new recurring issue:

1. Identify the category: CI/Workflow, Build/Packaging, or Application/Runtime
2. Create the file in the appropriate subfolder with a descriptive name
3. Follow the template:
   • Category
   • Issue (one-line summary)
   • Pattern to Avoid (code example)
   • Correct Approach (code example)
   • Why It Fails (root cause explanation)
   • Detection (how to find instances)
   • Test Reference (if automated test exists)
   • Related Commits (historical context)
4. Update this index with the new anti-pattern
5. Add automated test to your project's code pattern test file if feasible

Anti-pattern files: .claude/skills/code-sentinel/anti-patterns/