Enforce maximum line limit per file (512 lines)

[ywatanabe1989]

Summary

Large files tend to have more bugs and are harder to maintain. We should enforce a maximum line limit per file using pre-tool-use hooks.

Line Limits (from hook)

File Type	Max Lines
Python (.py), Shell (.sh), Elisp (.el)	512
TypeScript/JavaScript (.ts, .tsx, .js, .jsx)	512
CSS (.css)	512
HTML (.html, .htm)	1024
Markdown (.md)	512

Hook Implementation

The pre-tool-use hook at .claude/hooks/pre-tool-use/limit_line_numbers.sh:

# Thresholds (in lines)
THRESHOLD_TS=512
THRESHOLD_PY=512
THRESHOLD_CSS=512
THRESHOLD_HTML=1024
THRESHOLD_MARKDOWN=512

Behavior:

• Blocks file writes/edits that would exceed the threshold
• Allows incremental reduction (shrinking files already over limit)
• Skips test files (tests/, test_*.py, *_test.py)
• Guides refactoring via REFACTORING.md

Current Violations (>1000 lines)

• src/scitex/canvas/editor/flask_editor/templates/_scripts.py (4933 lines)
• src/scitex/plt/utils/_collect_figure_metadata.py (3384 lines)
• src/scitex/canvas/editor/_dearpygui_editor.py (1976 lines)
• src/scitex/scholar/core/Scholar.py (1857 lines)
• src/scitex/ai/classification/reporters/_SingleClassificationReporter.py (1778 lines)
• src/scitex/scholar/storage/_LibraryManager.py (1725 lines)
• src/scitex/canvas/editor/flask_editor/_core.py (1688 lines)
• src/scitex/canvas/editor/flask_editor/templates/_styles.py (1658 lines)
• src/scitex/plt/utils/_hitmap.py (1643 lines)
• src/scitex/ai/classification/timeseries/_TimeSeriesSlidingWindowSplit.py (1640 lines)

Action Items

• Enable hook in .claude/settings.local.json
• Create sub-issues for each file needing refactoring
• Document exceptions (auto-generated code, templates)

Benefits

• Improved readability and maintainability
• Easier code reviews
• Reduced bug density
• Better separation of concerns