Implement lcom4 cohesion metrics

[fummicc1]

Pull Request

Overview

Implement LCOM4 cohesion metrics calculator.

Type of Change

Please check all that apply:

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update
• 🔧 Refactoring (no functional changes)
• 🧪 Test improvements
• ⚡ Performance improvements
• 🔨 Build/CI improvements
• 🌍 Cross-platform compatibility changes

Related Issues

Closes #(issue number)
Related to #(issue number)

Changes Made

Core Changes

Tests

Documentation

Testing

Test Plan

• Unit tests pass
• Integration tests pass
• Manual testing completed
• Complexity analysis on self passes

Test Commands

# Commands used to test this change
swift test
swift run swift-complexity Sources --threshold 15

Complexity Analysis

Self-Analysis Required

• Complexity analysis run on changed files
• No functions exceed threshold (15)
• New complex code is justified and documented

Run swift-complexity on your changes:

# Analyze changed files for complexity
swift run swift-complexity [changed-files] --threshold 15 --format text

# For comprehensive analysis
swift run swift-complexity Sources --threshold 15 --recursive --format json

Results: (paste results here or indicate no high-complexity functions added)

Justification for complex functions: (if any functions exceed threshold)

Cross-Platform Compatibility

Platform Testing

• Changes tested on macOS (Apple Silicon)
• Changes tested on macOS (Intel)
• Changes tested on Linux (Ubuntu 22.04+)
• Platform-specific code properly conditionally compiled

Platform Considerations

• No platform-specific dependencies added
• Linux compatibility maintained
• macOS-specific features properly isolated (e.g., swift-format)

Performance Impact

• No performance impact
• Performance improved
• Performance regression (with justification)

Details: (if applicable)

Breaking Changes

• No breaking changes
• Breaking changes (describe below)

Breaking Changes Description: (if applicable)

Screenshots/Output

(If applicable, add screenshots or example output)

Result of swift-complexity source

Input

❯ .build/debug/SwiftComplexityCLI Sources/SwiftComplexityCore --lcom4 --project-root . --recursive 2>&1 | head -50

Output

Output

File: /Users/fumiyatanaka/Work/OSS_cur/swift-complexity/Sources/SwiftComplexityCore/Analysis/CognitiveComplexityCalculator.swift
Class Cohesion (LCOM4):
| Class/Struct              | Type   | LCOM4 | Methods | Properties | Cohesion   |
+---------------------------+--------+-------+---------+------------+------------+
| CognitiveComplexityCalcul | class  | 2     | 12      | 4          | moderate   |
+---------------------------+--------+-------+---------+------------+------------+
Total: 1 classes, Average LCOM4: 2.00, Low cohesion: 0

File: /Users/fumiyatanaka/Work/OSS_cur/swift-complexity/Sources/SwiftComplexityCore/Analysis/ComplexityAnalyzer.swift
Class Cohesion (LCOM4):
| Class/Struct              | Type   | LCOM4 | Methods | Properties | Cohesion   |
+---------------------------+--------+-------+---------+------------+------------+
| ComplexityAnalyzer        | actor  | 1     | 3       | 6          | high       |
+---------------------------+--------+-------+---------+------------+------------+
Total: 1 classes, Average LCOM4: 1.00, Low cohesion: 0

File: /Users/fumiyatanaka/Work/OSS_cur/swift-complexity/Sources/SwiftComplexityCore/Analysis/CyclomaticComplexityCalculator.swift
Class Cohesion (LCOM4):
| Class/Struct              | Type   | LCOM4 | Methods | Properties | Cohesion   |
+---------------------------+--------+-------+---------+------------+------------+
| CyclomaticComplexityCalcu | class  | 1     | 11      | 1          | high       |
+---------------------------+--------+-------+---------+------------+------------+
Total: 1 classes, Average LCOM4: 1.00, Low cohesion: 0

File: /Users/fumiyatanaka/Work/OSS_cur/swift-complexity/Sources/SwiftComplexityCore/Analysis/FunctionDetector.swift
Class Cohesion (LCOM4):
| Class/Struct              | Type   | LCOM4 | Methods | Properties | Cohesion   |
+---------------------------+--------+-------+---------+------------+------------+
| DetectedFunction          | struct | 1     | 1       | 4          | high       |
| FunctionDetector          | class  | 1     | 10      | 2          | high       |
+---------------------------+--------+-------+---------+------------+------------+
Total: 2 classes, Average LCOM4: 1.00, Low cohesion: 0

File: /Users/fumiyatanaka/Work/OSS_cur/swift-complexity/Sources/SwiftComplexityCore/Analysis/NominalTypeDetector.swift
Class Cohesion (LCOM4):
| Class/Struct              | Type   | LCOM4 | Methods | Properties | Cohesion   |
+---------------------------+--------+-------+---------+------------+------------+
| DetectedNominal           | struct | 1     | 1       | 4          | high       |
| NominalTypeDetector       | class  | 2     | 6       | 2          | moderate   |
+---------------------------+--------+-------+---------+------------+------------+
Total: 2 classes, Average LCOM4: 1.50, Low cohesion: 0

File: /Users/fumiyatanaka/Work/OSS_cur/swift-complexity/Sources/SwiftComplexityCore/Analysis/SemanticLCOMCalculator.swift
Class Cohesion (LCOM4):
| Class/Struct              | Type   | LCOM4 | Methods | Properties | Cohesion   |
+---------------------------+--------+-------+---------+------------+------------+
| UnionFind                 | class  | 1     | 4       | 2          | high       |
| SemanticLCOMCalculator    | actor  | 1     | 11      | 2          | high       |
| PropertyAccessVisitor     | class  | 1     | 3       | 2          | high       |
| MethodCallVisitor         | class  | 1     | 2       | 2          | high       |

Checklist

Code Quality

• Code follows the project's style guidelines
• Self-review of code completed
• Code is self-documenting with clear variable/function names
• Complex logic is commented where necessary

Testing

• Tests added for new functionality
• Existing tests updated as needed
• All tests pass locally
• Edge cases considered and tested

Documentation

• Documentation updated (if needed)
• README updated (if needed)
• CLAUDE.md updated (if architecture changes)
• API documentation updated (if applicable)

Dependencies

• No new dependencies added
• New dependencies justified and documented
• Package.swift updated appropriately
• Cross-platform compatibility verified for new dependencies

CI/CD

• CI pipeline passes (macOS & Linux)
• No new linting warnings introduced
• Code formatting validation passes (swift-format on macOS)
• Documentation linting passes (markdownlint)
• Self-complexity analysis in CI passes
• Release workflow compatibility maintained (if applicable)

Additional Notes

(Any additional information that reviewers should know)

---

For Reviewers

Review Checklist

• Complexity Analysis: Results are reasonable and justified
• Cross-Platform: Changes work on both macOS and Linux
• Test Coverage: Adequate test coverage for new functionality
• Documentation: Updated appropriately for changes
• CI/CD: All automated checks pass
• Architecture: Changes align with project goals and patterns
• Performance: No unexpected performance regressions
• Dependencies: New dependencies are justified and secure

Key Areas to Focus On

1. Code Quality: Maintainable, readable, and follows project conventions
2. Platform Compatibility: Proper handling of macOS/Linux differences
3. Complexity Management: New code doesn't unnecessarily increase complexity
4. Test Quality: Tests are comprehensive and meaningful
5. Documentation: Changes are properly documented for users and developers