Code Quality Analysis (Conceptual / Future Plan)

This document describes a future-facing design for quality analysis. The legacy quality module and QualityPass were removed from the codebase in the purge. Consider this document a proposal/reference for potential future work rather than current implementation.

Overview

Status: Not implemented. The legacy module was removed; this page documents future direction.

Quality analysis provides:

• Code smell detection
• Best practice validation
• Design pattern recognition
• Maintainability assessment
• Technical debt identification

Code Smells

Method-Level Smells

Long Method

Description: Method with too many lines of code

Threshold: > 50 lines (configurable)

Example:

public void ProcessOrder(Order order) {
    // 150 lines of code...
}

Diagnostic:

warning[QUAL001]: Long method detected
  --> src/OrderService.cs:42:17
   |
42 |     public void ProcessOrder(Order order) {
   |                 ^^^^^^^^^^^^ method has 150 lines (threshold: 50)
   |
   = help: Consider breaking this method into smaller, focused methods

Refactoring:

• Extract method
• Decompose into smaller methods
• Apply Single Responsibility Principle

Long Parameter List

Description: Method with too many parameters

Threshold: > 5 parameters (configurable)

Example:

public void CreateUser(string firstName, string lastName, string email, 
                      string phone, string address, string city, string zip) {
    // ...
}

Refactoring:

• Introduce parameter object
• Use builder pattern
• Group related parameters into DTOs

Complex Conditional

Description: Deeply nested or complex conditional logic

Example:

if (user != null && user.IsActive && (user.Role == "Admin" || user.Role == "Manager") 
    && user.Department != null && user.Department.Budget > 10000) {
    // ...
}

Refactoring:

• Extract condition to well-named method
• Use guard clauses
• Simplify boolean logic

Class-Level Smells

Large Class (God Class)

Description: Class with too many responsibilities

Indicators:

• Too many methods (> 20)
• Too many fields (> 10)
• High cyclomatic complexity
• Low cohesion

Example:

public class UserManager {
    // 50 methods handling user CRUD, authentication, authorization,
    // email sending, logging, caching, validation, etc.
}

Refactoring:

• Split into multiple classes
• Apply Single Responsibility Principle
• Extract related functionality

Feature Envy

Description: Method uses more features of another class than its own

Example:

public class OrderProcessor {
    public decimal CalculateTotal(Order order) {
        decimal total = 0;
        foreach (var item in order.Items) {
            total += item.Price * item.Quantity;
        }
        total -= order.Discount;
        total += order.Tax;
        return total;
    }
}

Refactoring:

• Move method to Order class
• Method should be where the data is

Data Class

Description: Class with only fields and getters/setters, no behavior

Example:

public class User {
    public string Name { get; set; }
    public string Email { get; set; }
    public int Age { get; set; }
    // No methods, just data
}

Note: Sometimes acceptable for DTOs, but domain objects should have behavior

Code Organization Smells

Duplicate Code

Description: Identical or very similar code in multiple places

Detection:

• Token-based comparison
• AST structure comparison
• Minimum clone size threshold

Refactoring:

• Extract method
• Extract class
• Use inheritance or composition

Dead Code

Description: Code that is never executed

Examples:

• Unreachable statements after return
• Unused private methods
• Unused fields
• Conditions that are always true/false

Diagnostic:

warning[QUAL010]: Unreachable code detected
  --> src/Calculator.cs:15:9
   |
14 |     return result;
15 |     Console.WriteLine("Done");  // Never executed
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement

Magic Numbers

Description: Unexplained numeric literals in code

Example:

if (order.Total > 1000) {  // What does 1000 mean?
    ApplyDiscount(order, 0.1);  // What does 0.1 mean?
}

Refactoring:

const decimal BULK_ORDER_THRESHOLD = 1000m;
const decimal BULK_ORDER_DISCOUNT = 0.1m;

if (order.Total > BULK_ORDER_THRESHOLD) {
    ApplyDiscount(order, BULK_ORDER_DISCOUNT);
}

Best Practices

Naming Conventions

Rules:

• Classes: PascalCase
• Methods: PascalCase
• Properties: PascalCase
• Fields: camelCase with _ prefix for private
• Constants: UPPER_CASE or PascalCase
• Interfaces: PascalCase with I prefix

Violations:

warning[QUAL020]: Naming convention violation
  --> src/UserService.cs:5:17
   |
 5 |     private int UserCount;
   |                 ^^^^^^^^^ private field should use camelCase with _ prefix
   |
   = help: Rename to '_userCount'

Exception Handling

Anti-patterns:

Empty Catch Block:

try {
    RiskyOperation();
} catch (Exception) {
    // Silent failure - BAD!
}

Catching Generic Exception:

try {
    SpecificOperation();
} catch (Exception ex) {  // Too broad
    // ...
}

Best Practices:

• Catch specific exceptions
• Log exceptions
• Don't swallow exceptions
• Use finally for cleanup

Resource Management

Using Statement:

// Good
using (var file = File.OpenRead("data.txt")) {
    // Use file
}

// Better (C# 8+)
using var file = File.OpenRead("data.txt");
// Disposed at end of scope

Diagnostic:

warning[QUAL030]: IDisposable not properly disposed
  --> src/FileProcessor.cs:10:9
   |
10 |     var file = File.OpenRead("data.txt");
   |         ^^^^ should be wrapped in using statement

Design Patterns and Anti-Patterns

Detected Patterns

Singleton Pattern

Detection:

• Private constructor
• Static instance field
• Public static accessor

Example:

public class Logger {
    private static Logger _instance;
    private Logger() { }
    
    public static Logger Instance {
        get {
            if (_instance == null) {
                _instance = new Logger();
            }
            return _instance;
        }
    }
}

Factory Pattern

Detection:

• Method returning interface or base class
• Creates different concrete types based on parameters

Anti-Patterns

God Object

Detection:

• High number of methods and fields
• Low cohesion
• High coupling

Spaghetti Code

Detection:

• High cyclomatic complexity
• Deep nesting
• Lack of structure

Lava Flow

Detection:

• Dead code
• Commented-out code
• Unused variables/methods

Quality Metrics

Code Quality Score

Composite Score (0-100):

#![allow(unused)]
fn main() {
pub struct QualityScore {
    pub overall: f64,
    pub maintainability: f64,
    pub complexity: f64,
    pub duplication: f64,
    pub test_coverage: f64,
}
}

Calculation:

Overall = (Maintainability * 0.3) + 
          (Complexity * 0.3) + 
          (Duplication * 0.2) + 
          (TestCoverage * 0.2)

Technical Debt

Estimation:

#![allow(unused)]
fn main() {
pub struct TechnicalDebt {
    pub total_issues: usize,
    pub estimated_hours: f64,
    pub debt_ratio: f64,  // debt / total development time
}
}

Calculation:

• Each code smell assigned time cost
• Sum all issues
• Compare to total codebase size

Quality Rules

Rule System

Rule Definition:

#![allow(unused)]
fn main() {
pub trait QualityRule {
    fn id(&self) -> &'static str;
    fn name(&self) -> &'static str;
    fn description(&self) -> &'static str;
    fn check(&self, node: &NodeRef, session: &mut AnalysisSession);
}
}

Example Rule:

#![allow(unused)]
fn main() {
pub struct LongMethodRule {
    max_lines: usize,
}

impl QualityRule for LongMethodRule {
    fn id(&self) -> &'static str { "long_method" }
    fn name(&self) -> &'static str { "Long Method" }
    
    fn check(&self, node: &NodeRef, session: &mut AnalysisSession) {
        if let NodeRef::MethodDeclaration(method) = node {
            let line_count = count_lines(method);
            if line_count > self.max_lines {
                session.diagnostics.add(
                    DiagnosticCode::LongMethod,
                    format!("Method has {} lines (threshold: {})", 
                           line_count, self.max_lines)
                );
            }
        }
    }
}
}

Rule Categories

Maintainability Rules:

• Long method
• Long parameter list
• Large class
• Complex method

Reliability Rules:

• Empty catch blocks
• Null reference risks
• Resource leaks
• Unhandled exceptions

Security Rules:

• SQL injection risks
• XSS vulnerabilities
• Hardcoded credentials
• Insecure random

Performance Rules:

• Inefficient loops
• Unnecessary allocations
• String concatenation in loops
• Boxing/unboxing

Configuration

Quality Thresholds

[analysis.quality]
max_method_lines = 50
max_parameters = 5
max_class_methods = 20
max_cyclomatic_complexity = 10
max_nesting_depth = 4

[analysis.quality.rules]
long_method = "warning"
long_parameter_list = "warning"
god_class = "error"
empty_catch = "error"
magic_numbers = "info"

Severity Levels

• Error: Must be fixed
• Warning: Should be fixed
• Info: Consider fixing
• Hint: Suggestion for improvement

CLI Usage

Quality Analysis

# Analyze code quality
bsharp analyze MyProject.csproj --enable-ruleset quality

# Generate quality report
bsharp analyze MySolution.sln --out quality-report.json

# Filter by severity
bsharp analyze MyFile.cs --severity error,warning

Example Output

{
  "quality_score": {
    "overall": 72.5,
    "maintainability": 68.0,
    "complexity": 75.0,
    "duplication": 80.0
  },
  "technical_debt": {
    "total_issues": 45,
    "estimated_hours": 12.5,
    "debt_ratio": 0.08
  },
  "diagnostics": [
    {
      "code": "QUAL001",
      "severity": "warning",
      "message": "Long method detected",
      "file": "src/OrderService.cs",
      "line": 42,
      "column": 17
    }
  ]
}

Integration with Pipeline

Quality Ruleset

Registration:

#![allow(unused)]
fn main() {
// In AnalyzerRegistry
registry.add_ruleset(QualityRuleset {
    id: "quality",
    rules: vec![
        Box::new(LongMethodRule::new()),
        Box::new(LongParameterListRule::new()),
        Box::new(GodClassRule::new()),
        Box::new(EmptyCatchRule::new()),
        // ... more rules
    ],
});
}

Execution:

• Rules run during Local or Semantic phase
• Visitor pattern for AST traversal
• Diagnostics collected in session

Programmatic Usage

Running Quality Analysis

#![allow(unused)]
fn main() {
use bsharp::analysis::quality::QualityAnalyzer;

let parser = Parser::new();
let cu = parser.parse(source_code)?;

let analyzer = QualityAnalyzer::new();
let report = analyzer.analyze(&cu);

println!("Quality Score: {}", report.quality_score.overall);
println!("Issues Found: {}", report.diagnostics.len());
}

Custom Rules

#![allow(unused)]
fn main() {
use bsharp::analysis::quality::QualityRule;

struct CustomRule;

impl QualityRule for CustomRule {
    fn id(&self) -> &'static str { "custom_rule" }
    fn name(&self) -> &'static str { "Custom Rule" }
    
    fn check(&self, node: &NodeRef, session: &mut AnalysisSession) {
        // Custom logic
    }
}

// Register custom rule
analyzer.add_rule(Box::new(CustomRule));
}

Future Enhancements

Planned Features

1. Machine Learning-Based Detection

   • Learn from codebase patterns
   • Detect project-specific smells

2. Refactoring Suggestions

   • Automated refactoring proposals
   • Preview refactoring impact

3. Quality Trends

   • Track quality over time
   • Identify degradation
   • Measure improvement

4. Team Metrics

   • Per-developer quality metrics
   • Code review insights
   • Best practice adoption

Related Documentation

• Analysis Pipeline - Pipeline integration
• Metrics Collection - Quality metrics
• Control Flow Analysis - Complexity analysis
• Architecture - Design decisions

References

• Standards: Clean Code (Robert C. Martin), Refactoring (Martin Fowler)