Quality Fixer

Quality Fix Applier

⚠️ MANDATORY: Read Project Documentation First

BEFORE applying quality fixes, you MUST read and understand the following project documentation:

Core Project Documentation

1. README.md - Project overview, features, and getting started
2. AI_DOCS/project-context.md - Tech stack, architecture, development workflow
3. AI_DOCS/code-conventions.md - Code style, formatting, best practices
4. AI_DOCS/tdd-workflow.md - TDD process, testing standards, coverage requirements

Session Context (if available)

5. .ai-context/ACTIVE_TASKS.md - Current tasks and priorities
6. .ai-context/CONVENTIONS.md - Project-specific conventions
7. .ai-context/RECENT_DECISIONS.md - Recent architectural decisions
8. .ai-context/LAST_SESSION_SUMMARY.md - Previous session summary

Additional AI Documentation

9. AI_DOCS/ai-tools.md - Session management workflow
10. AI_DOCS/ai-skills.md - Other specialized skills/agents available

Why This Matters

• Tool Configuration: Understand which formatters and linters are configured
• Code Standards: Apply fixes that align with project conventions
• Safety Rules: Know which auto-fixes are safe vs. require manual review
• Integration: Coordinate with other quality tools (Black, Ruff, isort)

After reading these files, proceed with your quality fixing task below.

Overview

Automatically apply safe quality fixes to Python code, resolving formatting issues, linting problems, and formatter conflicts.

When to Use

• After writing code, before running make check
• When make lint or make format reports fixable issues
• To resolve Black vs Ruff formatter conflicts
• Before committing code to ensure quality gates pass
• When you want to apply all safe, automatic fixes

What This Skill Fixes

✅ Formatting Issues

• Black code formatting
• isort import sorting
• Line length adjustments
• Whitespace normalization

✅ Linting Issues (Safe Auto-Fixes)

• Unused imports removal
• Unused variables (when safe)
• F-string conversion
• Simplifiable if statements
• List/dict comprehension improvements

✅ Type Hint Issues (Safe Cases)

• Add -> None to functions without return
• Add obvious type hints (str, int, bool literals)
• Fix Ellipsis in stub signatures

✅ Formatter Conflicts

• Black vs Ruff disagreements
• Message variable extraction for long strings
• Line break adjustments

Usage Examples

Fix All Issues in Project

# Run comprehensive quality fixes
apply quality fixes to the entire project

Actions:

1. Run make format (Black + isort)
2. Run Ruff with --fix flag
3. Check for and resolve formatter conflicts
4. Report what was fixed

Fix Specific File

# Fix a single file
fix quality issues in src/python_modern_template/validators.py

Actions:

1. Format the specific file
2. Apply Ruff fixes to that file
3. Verify no conflicts introduced
4. Show diff of changes

Resolve Formatter Conflicts Only

# Focus on conflicts
resolve Black and Ruff formatter conflicts

Actions:

1. Run both formatters
2. Identify lines where they disagree
3. Apply conflict resolution strategies
4. Verify both are satisfied

Preview Mode (Dry Run)

# See what would be fixed without applying
preview quality fixes for src/

Actions:

1. Run all checks in dry-run mode
2. Show what would be changed
3. Ask for confirmation before applying

Step-by-Step Process

Step 1: Run Formatting

# Apply Black formatting
make format

# This runs:
# - black src/ tests/
# - isort src/ tests/

What gets fixed:

• Code style (spacing, indentation, quotes)
• Import organization and grouping
• Line length compliance (88 characters)

Step 2: Apply Ruff Auto-Fixes

# Run Ruff with auto-fix
uv run ruff check --fix src/ tests/

# Safe fixes include:
# - Remove unused imports
# - Remove unused variables (when safe)
# - F-string conversion
# - Simplify expressions

What gets fixed:

• Import cleanup
• Code simplification
• Modern Python idioms

Step 3: Detect Formatter Conflicts

# Check if Black and Ruff agree
make format && make lint

Common conflicts:

• Long string literals exceeding line length
• Complex expressions needing line breaks
• Comment placement differences

Step 4: Resolve Conflicts

Strategy 1: Extract Message Variables

# Before (conflict - too long)
logger.error("This is a very long error message that exceeds the line length limit")

# After (resolved)
msg = "This is a very long error message that exceeds the line length limit"
logger.error(msg)

Strategy 2: Use Parentheses for Line Breaks

# Before (conflict)
result = some_function(arg1, arg2, arg3, arg4, arg5, arg6)

# After (resolved)
result = some_function(
    arg1, arg2, arg3, arg4, arg5, arg6
)

Strategy 3: Split Long Strings

# Before (conflict)
text = "This is a very long string that should be split across multiple lines for readability"

# After (resolved)
text = (
    "This is a very long string that should be "
    "split across multiple lines for readability"
)

Step 5: Verify Fixes

# Run complete quality check
make check

Must pass:

• ✅ Format (Black + isort)
• ✅ Lint (Ruff + Pylint + mypy)
• ✅ Tests (pytest)
• ✅ Security (Bandit)

Conflict Resolution Strategies

Identifying Conflicts

Run both tools and compare:

# Apply Black
black src/python_modern_template/module.py

# Check Ruff
ruff check src/python_modern_template/module.py

# If Ruff still complains about formatting, there's a conflict

Resolution Decision Tree

1. Long String Literals → Extract to variable or split across lines

2. Complex Expressions → Add parentheses and line breaks

3. Long Function Calls → Break arguments to multiple lines

4. Comment Placement → Move comments above the line

5. Type Annotation Complexity → Split to multiple lines with proper indentation

Example: Resolving Long String Conflict

Problem:

# Black formats this way:
raise ValueError("The email address provided is not valid because it does not contain the required @ symbol")

# Ruff complains: E501 Line too long (92 > 88)

Solution:

# Extract message variable
error_msg = (
    "The email address provided is not valid because it "
    "does not contain the required @ symbol"
)
raise ValueError(error_msg)

# Both Black and Ruff are satisfied!

What This Skill Does NOT Fix

❌ Complex Logic Issues

• Algorithm problems
• Business logic errors
• Design flaws

❌ Non-Obvious Type Hints

• Complex generic types
• Union types requiring domain knowledge
• Custom type aliases

❌ Docstring Content

• Will format docstrings
• Won't write missing docstrings
• Won't improve docstring quality

❌ Test Failures

• Only fixes code style
• Doesn't fix failing tests
• Doesn't add missing tests

❌ Breaking Changes

• Only applies safe, non-breaking fixes
• Won't remove used variables
• Won't change semantics

Output Format

After applying fixes, provide a report:

## Quality Fixes Applied

**Files Modified:** X
**Total Changes:** X lines

### Formatting Fixes
- ✅ Applied Black formatting to X files
- ✅ Sorted imports with isort in X files
- ✅ Fixed line length issues: X lines

### Linting Fixes
- ✅ Removed X unused imports
- ✅ Converted X strings to f-strings
- ✅ Simplified X expressions
- ✅ Fixed X Ruff issues

### Conflicts Resolved
- ✅ Extracted X message variables
- ✅ Split X long strings
- ✅ Reformatted X function calls

### Quality Check Results
```bash
make check

[Show output]

Files Changed

1. src/python_modern_template/module1.py (+12, -8)
2. src/python_modern_template/module2.py (+5, -3)
3. tests/test_module.py (+3, -2)

Next Steps

• Review changes with git diff
• Run tests to ensure no breaking changes: make test
• Commit changes if satisfied

## Safety Features

### Dry Run Mode

Always available for preview:

```bash
# Format preview
black --check --diff src/

# Ruff preview
ruff check --fix --diff src/

Git Integration

Verify changes before committing:

# See what changed
git diff

# Stage specific changes
git add -p

Backup Strategy

For large fixes, create a commit first:

# Commit current state
git commit -m "Before quality fixes"

# Apply fixes
[quality-fixer runs]

# Review changes
git diff HEAD~1

# Undo if needed
git reset --hard HEAD~1

Integration with Project Tools

Makefile Integration

# Just formatting
make format

# Just linting (with fixes)
make lint

# Complete check (no auto-fix)
make check

Pre-Commit Integration

Add to .pre-commit-config.yaml:

- repo: local
  hooks:
    - id: quality-fixer
      name: Quality Fixer
      entry: python .claude/skills/quality-fixer/scripts/auto_fix.py
      language: system
      types: [python]

CI Integration

Run in CI with --check mode:

# CI should verify, not fix
make check

# If it fails, developers run:
[quality-fixer to fix locally]

Advanced Features

Selective Fixing

Fix only specific types of issues:

# Only formatting
[quality-fixer] --format-only

# Only import cleanup
[quality-fixer] --imports-only

# Only conflicts
[quality-fixer] --conflicts-only

Ignore Patterns

Respect configuration in pyproject.toml:

[tool.ruff.lint]
ignore = ["E501"]  # Don't auto-fix line length in specific cases

[tool.black]
extend-exclude = '''
/(
  | generated
)/
'''

Custom Rules

Define project-specific fixes:

# .claude/skills/quality-fixer/scripts/custom_rules.py

def fix_common_typos(code: str) -> str:
    """Fix project-specific common mistakes."""
    fixes = {
        "recieve": "receive",
        "seperator": "separator",
    }
    for typo, correction in fixes.items():
        code = code.replace(typo, correction)
    return code

Best Practices

1. Run before committing - Always clean up code before commits
2. Review changes - Don't blindly accept all fixes, use git diff
3. Test after fixing - Run make test to ensure no breaking changes
4. Fix iteratively - Start with formatting, then linting, then conflicts
5. Understand the changes - Learn from fixes to avoid future issues

Common Scenarios

Scenario 1: Before Committing

# 1. Apply fixes
[quality-fixer]

# 2. Review changes
git diff

# 3. Test
make test

# 4. Commit
git add .
git commit -m "feat: add new feature"

Scenario 2: After Code Review

# Code reviewer says: "Fix formatting and linting"

# 1. Apply fixes
[quality-fixer]

# 2. Verify all issues resolved
make check

# 3. Push
git push

Scenario 3: CI Failure

# CI reports quality issues

# 1. Pull latest
git pull

# 2. Apply fixes
[quality-fixer]

# 3. Verify locally
make check

# 4. Push fix
git commit -am "fix: resolve quality issues"
git push

Troubleshooting

"Black and Ruff still conflict after fix"

Solution: Manually review the conflicting lines and apply advanced strategies:

• Extract complex expressions to variables
• Restructure the code for better formatting
• Use # noqa comments sparingly for unavoidable cases

"Auto-fix broke my tests"

Solution:

• Revert with git checkout -- <file>
• Review what was changed with git diff
• Apply fixes more selectively
• Report if a fix is unsafe (should not be applied)

"Pylint still reports issues"

Note: This skill only applies auto-fixable issues. Pylint often requires manual fixes:

• Unused arguments → Use _ prefix or remove
• Too many arguments → Refactor function
• Too complex → Simplify logic

Remember

Quality fixes are TOOLS, not SUBSTITUTES for good code:

• Write clean code from the start
• Understand why formatters want changes
• Learn from the fixes applied
• Don't rely on auto-fix for everything

This skill helps you maintain code quality efficiently, but good coding practices are still essential!