# Quality Validation CLI Tool - Technical Architecture and Implementation Guide

**Document ID:** QUAL-ARCH-001
**Version:** 1.0
**Date:** January 20, 2025
**Status:** APPROVED FOR DEVELOPMENT

---

## 1. System Architecture Overview

### 1.1 High-Level Architecture Diagram

```
┌───────────────────────────────────────────────────────────────────┐
│                    Quality Validation CLI                          │
├───────────────────────────────────────────────────────────────────┤
│                                                                    │
│  ┌──────────────────────────────────────────────────────────┐    │
│  │  Command-Line Interface (CLI Entry Point)                │    │
│  │  - Argument parsing (yargs)                              │    │
│  │  - Command routing                                       │    │
│  │  - Configuration loading                                 │    │
│  └──────────────────────────────────────────────────────────┘    │
│                                                                    │
│  ┌─────────────────────┐  ┌──────────────────────────────┐       │
│  │ Configuration       │  │ Analysis Pipeline            │       │
│  │ Manager             │  │                              │       │
│  │ - .qualityrc.json   │  │ ┌──────────────────────┐    │       │
│  │ - Defaults          │  │ │Code Quality Analyzer │    │       │
│  │ - Validation        │  │ │ - Complexity         │    │       │
│  └─────────────────────┘  │ │ - Duplication        │    │       │
│                            │ │ - Linting            │    │       │
│                            │ └──────────────────────┘    │       │
│                            │                              │       │
│                            │ ┌──────────────────────┐    │       │
│                            │ │Test Coverage         │    │       │
│                            │ │Validator             │    │       │
│                            │ │ - Coverage metrics   │    │       │
│                            │ │ - Coverage gaps      │    │       │
│                            │ │ - Test effectiveness │    │       │
│                            │ └──────────────────────┘    │       │
│                            │                              │       │
│                            │ ┌──────────────────────┐    │       │
│                            │ │Architecture          │    │       │
│                            │ │Compliance Checker    │    │       │
│                            │ │ - Component patterns │    │       │
│                            │ │ - Dependencies       │    │       │
│                            │ │ - Redux patterns     │    │       │
│                            │ └──────────────────────┘    │       │
│                            │                              │       │
│                            │ ┌──────────────────────┐    │       │
│                            │ │Security Scanner      │    │       │
│                            │ │ - Vulnerabilities    │    │       │
│                            │ │ - Anti-patterns      │    │       │
│                            │ │ - Secrets detection  │    │       │
│                            │ └──────────────────────┘    │       │
│  └──────────────────────────────────────────────────────┘       │
│                            │                                     │
│                    ┌───────▼──────────┐                          │
│                    │ Metrics          │                          │
│                    │ Aggregator       │                          │
│                    │ - Combine        │                          │
│                    │ - Normalize      │                          │
│                    │ - Calculate score│                          │
│                    └───────┬──────────┘                          │
│                            │                                     │
│                    ┌───────▼──────────┐                          │
│                    │ Scoring Engine   │                          │
│                    │ - Apply weights  │                          │
│                    │ - Grade          │                          │
│                    │ - Trend analysis │                          │
│                    └───────┬──────────┘                          │
│                            │                                     │
│        ┌───────────────────┼───────────────────┬─────────────┐  │
│        │                   │                   │             │  │
│  ┌─────▼────┐       ┌──────▼──────┐     ┌─────▼──┐    ┌────▼──┐ │
│  │Console   │       │JSON Export  │     │HTML    │    │CSV    │ │
│  │Reporter  │       │             │     │Report  │    │Export │ │
│  │          │       │             │     │        │    │       │ │
│  │✓ Colors  │       │✓ Schema     │     │✓Chart  │    │✓Data  │ │
│  │✓ Summary │       │✓Structured  │     │✓Inter- │    │✓File- │ │
│  │✓ Details │       │✓Machine     │     │active  │    │level  │ │
│  │          │       │  readable   │     │✓Links  │    │       │ │
│  └──────────┘       └─────────────┘     └────────┘    └───────┘ │
│                                                                    │
└───────────────────────────────────────────────────────────────────┘
```

### 1.2 Module Responsibilities

| Module | Responsibility | Input | Output |
|--------|----------------|-------|--------|
| **CLI Entry** | Parse arguments, route commands | CLI args | Command execution |
| **Configuration Manager** | Load and validate config | .qualityrc.json, defaults | Merged config object |
| **Code Quality Analyzer** | Complexity, duplication, linting | Source files, AST | Quality metrics |
| **Test Coverage Validator** | Coverage metrics and gaps | coverage-final.json | Coverage report |
| **Architecture Checker** | Component structure, dependencies | Source files | Architecture findings |
| **Security Scanner** | Vulnerabilities, anti-patterns | Dependencies, source code | Security findings |
| **Metrics Aggregator** | Combine all metrics | Individual metric reports | Aggregated metrics |
| **Scoring Engine** | Calculate grade and score | Aggregated metrics | Overall grade/score |
| **Reporter Engines** | Format and display results | Scoring results | Formatted reports |

---

## 2. Data Flow Architecture

### 2.1 Analysis Pipeline Flow

```
Input Files
    │
    ├─► Filter & Validate
    │   - Exclude node_modules
    │   - Exclude dist, build
    │   - Verify files are readable
    │
    ├─► Parse & Build AST
    │   - TypeScript compiler
    │   - Extract structure
    │
    ├─► Parallel Analysis
    │   ├─► Complexity Analysis
    │   │   ├─► Cyclomatic calculation
    │   │   └─► Threshold checking
    │   │
    │   ├─► Duplication Detection
    │   │   ├─► Code normalization
    │   │   └─► Similarity matching
    │   │
    │   ├─► Linting Analysis
    │   │   ├─► Run ESLint
    │   │   └─► Aggregate violations
    │   │
    │   └─► Architecture Validation
    │       ├─► Component classification
    │       └─► Dependency analysis
    │
    ├─► Coverage Analysis
    │   ├─► Read coverage data
    │   ├─► Calculate metrics
    │   └─► Identify gaps
    │
    ├─► Security Scan
    │   ├─► npm audit
    │   ├─► Pattern scanning
    │   └─► Secret detection
    │
    ├─► Aggregate Results
    │   ├─► Normalize scores
    │   ├─► Apply weights
    │   └─► Calculate grade
    │
    └─► Generate Reports
        ├─► Console output
        ├─► JSON export
        ├─► HTML report
        └─► Historical tracking
```

---

## 3. Module Specifications

### 3.1 Code Quality Analyzer Module

**File:** `src/lib/quality-validator/code-quality-analyzer.ts`

**Purpose:** Analyze code for complexity, duplication, and style issues.

#### 3.1.1 Cyclomatic Complexity Analyzer

```typescript
interface ComplexityAnalysis {
  functionName: string;
  filePath: string;
  startLine: number;
  endLine: number;
  complexity: number;
  severity: 'good' | 'warning' | 'critical';
  components: ComplexityComponent[];
}

interface ComplexityComponent {
  type: 'if' | 'else-if' | 'switch' | 'case' | 'loop' | 'logical-operator' | 'catch';
  count: number;
}

function calculateCyclomaticComplexity(node: ts.FunctionDeclaration | ts.ArrowFunction): number {
  // Traverse AST counting decision points
  // Each if/switch/case/loop = +1
  // Each catch = +1
  // Each && or || = +1
}
```

**Algorithm:**
1. Parse source files into AST using TypeScript compiler
2. Visit each function node
3. Count decision points (if/switch/case/loop/logical operators)
4. Apply threshold (0-10: good, 11-20: warning, >20: critical)
5. Return detailed report with severity

**Performance:** O(n) where n = number of functions

#### 3.1.2 Code Duplication Detector

```typescript
interface DuplicationBlock {
  lines: string[];
  size: number; // number of lines
  locations: DuplicationLocation[];
  duplicationPercentage: number;
  suggestedRefactoring: string;
}

interface DuplicationLocation {
  file: string;
  startLine: number;
  endLine: number;
}

function detectDuplication(sourceFiles: SourceFile[]): DuplicationReport {
  // 1. Normalize all code (remove comments, whitespace variations)
  // 2. Split into blocks of 4+ lines
  // 3. Hash each block
  // 4. Find matching hashes (exact and near-exact)
  // 5. Calculate duplication percentage
  // 6. Return findings with suggestions
}
```

**Algorithm:**
1. Extract all code blocks (minimum 4 consecutive lines)
2. Normalize blocks (remove comments, standardize whitespace)
3. Hash normalized blocks
4. Group identical hashes
5. Identify duplication locations
6. Calculate duplication percentage (duplicate lines / total lines)
7. Generate refactoring suggestions based on pattern

**Thresholds:**
- Green: < 3%
- Yellow: 3-5%
- Red: > 5%

#### 3.1.3 Code Style Validator

```typescript
interface LintingViolation {
  file: string;
  line: number;
  column: number;
  severity: 'error' | 'warning' | 'info';
  rule: string;
  message: string;
  fixable: boolean;
  fix?: string;
}

interface LintingReport {
  totalViolations: number;
  errorCount: number;
  warningCount: number;
  infoCount: number;
  violations: LintingViolation[];
  byRule: Map<string, LintingViolation[]>;
  passStatus: boolean; // <= 3 errors AND <= 15 warnings
}

function analyzeLinting(): LintingReport {
  // 1. Execute ESLint with project configuration
  // 2. Parse results
  // 3. Group by severity and rule
  // 4. Calculate pass/fail status
  // 5. Return detailed report
}
```

**Integration:**
- Uses existing ESLint configuration
- Respects .eslintignore patterns
- Reports auto-fixable violations separately

### 3.2 Test Coverage Validator Module

**File:** `src/lib/quality-validator/test-coverage-validator.ts`

#### 3.2.1 Coverage Metrics Calculator

```typescript
interface CoverageMetrics {
  lines: {
    total: number;
    covered: number;
    percentage: number;
    status: 'excellent' | 'acceptable' | 'poor';
  };
  branches: {
    total: number;
    covered: number;
    percentage: number;
    status: 'excellent' | 'acceptable' | 'poor';
  };
  functions: {
    total: number;
    covered: number;
    percentage: number;
    status: 'excellent' | 'acceptable' | 'poor';
  };
  statements: {
    total: number;
    covered: number;
    percentage: number;
    status: 'excellent' | 'acceptable' | 'poor';
  };
  byFile: Map<string, FileCoverage>;
}

interface FileCoverage {
  file: string;
  lines: number;
  linesCovered: number;
  linesCoverage: number;
  branches: number;
  branchesCovered: number;
  functions: number;
  functionsCovered: number;
}

function parseCoverageData(jestCoveragePath: string): CoverageMetrics {
  // 1. Read coverage-final.json from Jest
  // 2. Aggregate metrics
  // 3. Calculate percentages
  // 4. Determine status (excellent: >=80%, acceptable: 60-79%, poor: <60%)
  // 5. Sort files by coverage
  // 6. Return detailed metrics
}
```

#### 3.2.2 Test Effectiveness Analyzer

```typescript
interface TestEffectivenessReport {
  totalTestFiles: number;
  totalTestCases: number;
  testsPerFile: number;
  averageAssertionsPerTest: number;
  testsWithoutAssertions: TestFile[];
  excessivelyMockedTests: TestFile[];
  poorlyNamedTests: TestCase[];
  effectivenessScore: number; // 0-100
}

interface TestFile {
  file: string;
  testCount: number;
  issues: TestIssue[];
}

interface TestCase {
  file: string;
  name: string;
  issue: string;
  suggestion: string;
}

function analyzeTestEffectiveness(): TestEffectivenessReport {
  // 1. Parse test files
  // 2. Count test cases
  // 3. Analyze test naming conventions
  // 4. Count assertions per test
  // 5. Identify tests without assertions
  // 6. Detect excessive mocking
  // 7. Calculate effectiveness score
  // 8. Return detailed findings
}
```

### 3.3 Architecture Compliance Checker Module

**File:** `src/lib/quality-validator/architecture-checker.ts`

#### 3.3.1 Component Architecture Validator

```typescript
interface ComponentAnalysis {
  name: string;
  file: string;
  type: 'atom' | 'molecule' | 'organism' | 'template' | 'unknown';
  expectedType: 'atom' | 'molecule' | 'organism' | 'template';
  isCorrectType: boolean;
  size: number; // lines of code
  sizeStatus: 'good' | 'warning' | 'critical';
  props: PropAnalysis[];
  imports: string[];
}

interface PropAnalysis {
  name: string;
  type: string;
  required: boolean;
}

interface ArchitectureReport {
  components: ComponentAnalysis[];
  misplacedComponents: ComponentAnalysis[];
  oversizedComponents: ComponentAnalysis[];
  circularDependencies: CircularDependency[];
  recommendations: string[];
}

function validateComponentArchitecture(): ArchitectureReport {
  // 1. Scan component files
  // 2. Classify by folder structure
  // 3. Measure file size
  // 4. Analyze imports for dependencies
  // 5. Detect circular dependencies
  // 6. Generate recommendations
  // 7. Return findings
}
```

#### 3.3.2 Module Dependency Analyzer

```typescript
interface DependencyGraph {
  nodes: DepNode[];
  edges: DepEdge[];
  circularDependencies: CircularPath[];
  layerViolations: LayerViolation[];
}

interface DepNode {
  file: string;
  type: 'component' | 'hook' | 'util' | 'store' | 'type';
  layer: number;
}

interface DepEdge {
  from: string;
  to: string;
  weight: number;
}

interface CircularPath {
  path: string[];
  files: string[];
}

function analyzeDependencies(): DependencyGraph {
  // 1. Build module dependency graph from imports
  // 2. Perform cycle detection (DFS)
  // 3. Check for layer violations
  // 4. Return dependency analysis
}
```

### 3.4 Security Scanner Module

**File:** `src/lib/quality-validator/security-scanner.ts`

#### 3.4.1 Vulnerability Detector

```typescript
interface SecurityFinding {
  type: 'vulnerability' | 'anti-pattern' | 'secret' | 'performance';
  severity: 'critical' | 'high' | 'medium' | 'low';
  file?: string;
  line?: number;
  column?: number;
  message: string;
  remediation: string;
}

interface SecurityReport {
  criticalCount: number;
  highCount: number;
  mediumCount: number;
  lowCount: number;
  findings: SecurityFinding[];
  dependencyVulnerabilities: DependencyVulnerability[];
}

interface DependencyVulnerability {
  package: string;
  currentVersion: string;
  vulnerability: string;
  severity: 'critical' | 'high' | 'medium' | 'low';
  fixedInVersion: string;
}

function scanSecurity(): SecurityReport {
  // 1. Run npm audit and parse results
  // 2. Scan code for hard-coded secrets
  // 3. Detect unsafe patterns (dangerouslySetInnerHTML, etc.)
  // 4. Find unvalidated input usage
  // 5. Return findings with remediation
}
```

**Pattern Detection:**
- Variables/comments containing: "password", "secret", "token", "apiKey"
- `dangerouslySetInnerHTML` usage
- Numeric literals > 1000 (potential IDs)
- Direct string concatenation in security contexts

---

## 4. Configuration System

### 4.1 Configuration Schema

**File:** `.qualityrc.json`

```json
{
  "codeQuality": {
    "enabled": true,
    "complexity": {
      "threshold": {
        "warning": 15,
        "critical": 20
      }
    },
    "duplication": {
      "minBlockSize": 4,
      "threshold": {
        "warning": 3,
        "critical": 5
      }
    },
    "linting": {
      "maxErrors": 3,
      "maxWarnings": 15
    }
  },
  "testCoverage": {
    "enabled": true,
    "minimums": {
      "lines": 80,
      "branches": 80,
      "functions": 80,
      "statements": 80
    }
  },
  "architecture": {
    "enabled": true,
    "maxComponentSize": 500,
    "warningComponentSize": 300
  },
  "security": {
    "enabled": true,
    "checkVulnerabilities": true,
    "checkSecrets": true,
    "checkAntiPatterns": true
  },
  "scoring": {
    "weights": {
      "codeQuality": 0.30,
      "testCoverage": 0.35,
      "architecture": 0.20,
      "security": 0.15
    }
  },
  "history": {
    "enabled": true,
    "maxRuns": 10,
    "storePath": ".quality"
  },
  "exclude": {
    "paths": [
      "node_modules",
      "dist",
      "build",
      "coverage",
      ".next"
    ],
    "files": [
      "*.d.ts",
      "*.spec.ts",
      "*.test.ts"
    ]
  }
}
```

### 4.2 Configuration Validation

```typescript
interface QualityConfig {
  codeQuality: CodeQualityConfig;
  testCoverage: TestCoverageConfig;
  architecture: ArchitectureConfig;
  security: SecurityConfig;
  scoring: ScoringConfig;
  history: HistoryConfig;
  exclude: ExcludePatterns;
}

function loadConfiguration(projectRoot: string): QualityConfig {
  // 1. Look for .qualityrc.json in project root
  // 2. Load and parse JSON
  // 3. Validate against schema
  // 4. Merge with defaults
  // 5. Return validated config
}

function validateConfiguration(config: unknown): config is QualityConfig {
  // Schema validation using zod or joi
  // Return true if valid, throw if invalid
}
```

---

## 5. Scoring Algorithm

### 5.1 Score Calculation

```typescript
interface QualityScore {
  codeQuality: CategoryScore;
  testCoverage: CategoryScore;
  architecture: CategoryScore;
  security: CategoryScore;
  overall: {
    score: number; // 0-100
    grade: 'A' | 'B' | 'C' | 'D' | 'F';
    status: 'pass' | 'fail';
  };
}

interface CategoryScore {
  score: number; // 0-100
  weight: number;
  metrics: MetricScore[];
}

function calculateScore(metrics: AggregatedMetrics): QualityScore {
  // 1. Normalize each metric to 0-100 scale
  // 2. Calculate category scores (average of metrics)
  // 3. Apply weights to categories
  // 4. Calculate overall score
  // 5. Assign grade based on score ranges:
  //    A: 90-100
  //    B: 80-89
  //    C: 70-79
  //    D: 60-69
  //    F: < 60
  // 6. Return score with grade
}
```

### 5.2 Metric Normalization

```
Normalization Formula:
normalizedScore = (metricValue / maxExpectedValue) * 100

Examples:
- Complexity: lower is better
  - CC <= 10: 100 points
  - CC 11-20: 50 points
  - CC > 20: 0 points

- Coverage: higher is better
  - >= 80%: 100 points
  - 60-79%: proportional
  - < 60%: 0 points

- Duplication: lower is better
  - < 3%: 100 points
  - 3-5%: 50 points
  - > 5%: 0 points
```

---

## 6. Report Generation

### 6.1 Console Reporter

**Output Example:**

```
╔════════════════════════════════════════════════════════════╗
║          Quality Validation Report - snippet-pastebin       ║
╚════════════════════════════════════════════════════════════╝

Overall Score: 87 / 100  [GRADE: B]  ✓ PASS

────────────────────────────────────────────────────────────

CODE QUALITY                                            78/100
├─ Cyclomatic Complexity .......................... 85/100 ✓
│  └─ 3 functions with high complexity (review)
├─ Code Duplication ............................... 92/100 ✓
│  └─ 1.2% duplication (excellent)
└─ Linting ....................................... 65/100 ⚠
   └─ 4 errors, 12 warnings (fix before merge)

TEST COVERAGE                                           92/100
├─ Line Coverage ................................. 85%  ✓
├─ Branch Coverage ................................ 78%  ⚠
├─ Function Coverage .............................. 88%  ✓
└─ Test Effectiveness ............................. 88/100 ✓

ARCHITECTURE COMPLIANCE                                 92/100
├─ Component Organization ......................... ✓ OK
├─ Dependency Analysis ............................. ✓ OK
│  └─ No circular dependencies detected
└─ Component Size .................................. ⚠
   └─ 2 components > 300 LOC (recommend splitting)

SECURITY & VULNERABILITIES                            85/100
├─ Dependency Vulnerabilities ..................... ✓ OK
│  └─ 0 critical, 0 high severity
├─ Anti-Pattern Detection ......................... ✓ OK
│  └─ No dangerous patterns found
└─ Performance Issues ............................. ⚠
   └─ 3 potential optimizations identified

────────────────────────────────────────────────────────────

TOP IMPROVEMENT AREAS:
1. Reduce linting violations (4 errors, 12 warnings)
2. Increase branch coverage from 78% to 80%+
3. Review component sizes (2 components need splitting)

Execution Time: 12.4 seconds
Analysis Date: 2025-01-20 14:32:15 UTC
```

### 6.2 JSON Reporter

**Schema:**

```json
{
  "metadata": {
    "timestamp": "2025-01-20T14:32:15Z",
    "toolVersion": "1.0.0",
    "projectPath": "/path/to/snippet-pastebin",
    "executionTime": 12.4
  },
  "overall": {
    "score": 87,
    "grade": "B",
    "status": "pass",
    "message": "Code quality is good with minor improvements needed"
  },
  "categories": {
    "codeQuality": {
      "score": 78,
      "weight": 0.30,
      "weighted_score": 23.4,
      "metrics": {
        "complexity": { "score": 85, "status": "good" },
        "duplication": { "score": 92, "status": "good" },
        "linting": { "score": 65, "status": "warning" }
      }
    },
    "testCoverage": {
      "score": 92,
      "weight": 0.35,
      "weighted_score": 32.2,
      "metrics": {
        "lines": 85,
        "branches": 78,
        "functions": 88,
        "statements": 85
      }
    },
    "architecture": {
      "score": 92,
      "weight": 0.20,
      "weighted_score": 18.4
    },
    "security": {
      "score": 85,
      "weight": 0.15,
      "weighted_score": 12.75
    }
  },
  "findings": [
    {
      "id": "COMPLEXITY-001",
      "category": "codeQuality",
      "severity": "warning",
      "title": "High Cyclomatic Complexity",
      "file": "src/components/SnippetManager.tsx",
      "line": 142,
      "metric": "complexity",
      "value": 22,
      "threshold": 20,
      "message": "Function has cyclomatic complexity of 22 (threshold: 20)",
      "remediation": "Extract sub-functions to reduce complexity"
    }
  ],
  "thresholds": {
    "overall_score_pass": 60,
    "overall_grade": "D"
  }
}
```

### 6.3 HTML Reporter

**Features:**
- Standalone single-file HTML with embedded CSS/JS
- Responsive design (mobile/tablet/desktop)
- Interactive charts and tables
- Drill-down capability for details
- Comparison with historical data
- Professional styling

**Structure:**
```
<html>
  <head>
    <style><!-- All CSS embedded --></style>
  </head>
  <body>
    <div class="container">
      <header>Quality Validation Report</header>
      <section class="summary">
        <!-- Overall score, grade, status -->
      </section>
      <section class="categories">
        <!-- Code Quality, Test Coverage, Architecture, Security -->
      </section>
      <section class="findings">
        <!-- Detailed findings with drill-down -->
      </section>
      <section class="trends">
        <!-- Historical comparison charts -->
      </section>
    </div>
    <script><!-- All JavaScript embedded --></script>
  </body>
</html>
```

---

## 7. Technology Stack

### 7.1 Core Dependencies

| Package | Version | Purpose |
|---------|---------|---------|
| **typescript** | ^5.0 | Language and type safety |
| **ts-node** | ^10.0 | Execute TypeScript directly |
| **yargs** | ^17.0 | CLI argument parsing |
| **chalk** | ^5.0 | Terminal colors and styling |
| **eslint** | ^8.0 | Code linting (existing) |
| **jest** | ^29.0 | Test framework (existing) |

### 7.2 Analysis Dependencies

| Package | Purpose |
|---------|---------|
| **typescript** (compiler API) | AST parsing for complexity analysis |
| **glob** | File pattern matching |
| **ignore** | Respect .eslintignore patterns |

### 7.3 Report Generation

| Package | Purpose |
|---------|---------|
| **html-escaper** | Escape HTML in JSON data |
| **chart.js** | Embedded for HTML charts |

---

## 8. CLI Interface Design

### 8.1 Command Structure

```bash
# Main quality check
npm run quality:check

# With options
npm run quality:check --format json --output report.json
npm run quality:check --format html --output report.html
npm run quality:check --category codeQuality
npm run quality:check --verbose

# Quick check (less detail, faster)
npm run quality:quick

# Detailed report
npm run quality:detailed

# Help
npm run quality:check -- --help
```

### 8.2 Exit Codes

| Code | Meaning | Usage |
|------|---------|-------|
| 0 | Success - quality passes all thresholds | CI/CD pass |
| 1 | Failure - quality below thresholds | CI/CD fail |
| 2 | Error - tool error or invalid args | Troubleshooting |

---

## 9. Error Handling Strategy

### 9.1 Error Categories

| Category | Example | Handling |
|----------|---------|----------|
| **Configuration** | Invalid .qualityrc.json | Exit with helpful error message |
| **File Access** | Cannot read source files | Log warning, continue with available files |
| **Tool Execution** | ESLint fails | Continue with partial results |
| **Data Parsing** | Malformed coverage JSON | Use defaults, report warning |
| **Output Generation** | Cannot write HTML file | Exit with clear error |

### 9.2 Error Messages

```typescript
interface ErrorReport {
  severity: 'error' | 'warning';
  code: string;
  message: string;
  suggestion?: string;
  context?: string;
}

function reportError(error: ErrorReport): void {
  console.error(`[${error.code}] ${error.message}`);
  if (error.suggestion) {
    console.error(`Suggestion: ${error.suggestion}`);
  }
  if (error.context) {
    console.error(`Context: ${error.context}`);
  }
}
```

---

## 10. Performance Optimization

### 10.1 Target Metrics

| Metric | Target | Approach |
|--------|--------|----------|
| **Total Time** | < 30s | Parallel analysis |
| **Memory** | < 512 MB | Stream processing |
| **Large Projects** | 500+ components | Lazy evaluation |

### 10.2 Optimization Strategies

1. **Parallel Analysis**
   - Run independent analyses simultaneously (complexity, duplication, linting)
   - Use Node.js worker threads for heavy processing

2. **Caching**
   - Cache AST parsing results
   - Cache file content hashing
   - Reuse ESLint results if available

3. **Lazy Evaluation**
   - Only analyze requested categories
   - Skip deep analysis if quick check requested

4. **Stream Processing**
   - Stream large files for duplication detection
   - Process line-by-line for duplication matching

---

## 11. Testing Strategy

### 11.1 Test Coverage Goals

- **Unit Tests:** 80%+ coverage of analysis modules
- **Integration Tests:** Happy path and error scenarios
- **End-to-End Tests:** Full analysis pipeline

### 11.2 Test Categories

```typescript
// Unit Tests
- ComplexityCalculator.test.ts
- DuplicationDetector.test.ts
- LintingAnalyzer.test.ts
- CoverageCalculator.test.ts
- ArchitectureChecker.test.ts
- SecurityScanner.test.ts
- ScoringEngine.test.ts
- Reporters.test.ts

// Integration Tests
- AnalysisPipeline.integration.test.ts
- ConfigurationLoading.integration.test.ts
- CLIIntegration.integration.test.ts

// End-to-End Tests
- FullAnalysis.e2e.test.ts
```

---

## 12. Implementation Phases

### Phase 1: Foundation (Week 1-2)
- CLI entry point
- Configuration system
- Base module structure
- Complexity analyzer
- Test coverage validator

### Phase 2: Core Analysis (Week 3-4)
- Duplication detector
- Linting analyzer
- Architecture checker
- Security scanner

### Phase 3: Reporting (Week 5)
- Metrics aggregation
- Scoring engine
- Console reporter
- JSON reporter

### Phase 4: Advanced Features (Week 6-7)
- HTML reporter
- Historical tracking
- Trend analysis
- Performance optimization

---

## 13. File Structure

```
src/
├── cli/
│   ├── index.ts           # Entry point
│   ├── commands.ts        # Command definitions
│   └── cli-parser.ts      # Argument parsing
├── lib/
│   ├── quality-validator/
│   │   ├── index.ts       # Main export
│   │   ├── code-quality-analyzer.ts
│   │   ├── test-coverage-validator.ts
│   │   ├── architecture-checker.ts
│   │   ├── security-scanner.ts
│   │   ├── metrics-aggregator.ts
│   │   ├── scoring-engine.ts
│   │   └── reporters/
│   │       ├── console-reporter.ts
│   │       ├── json-reporter.ts
│   │       ├── html-reporter.ts
│   │       └── csv-reporter.ts
│   ├── config/
│   │   ├── loader.ts      # Configuration loading
│   │   └── validator.ts   # Configuration validation
│   ├── utils/
│   │   ├── file-utils.ts
│   │   ├── ast-utils.ts
│   │   └── normalize.ts
│   └── types/
│       └── index.ts       # All TypeScript interfaces
├── scripts/
│   └── quality-check.ts   # npm script entry point
└── __tests__/
    ├── unit/
    ├── integration/
    └── e2e/
```

---

## 14. Success Metrics for Implementation

- Code quality tool reaches production-ready state
- Achieves 80%+ test coverage for own code
- Analyzes snippet-pastebin project in < 30 seconds
- Detects > 95% of simulated quality issues
- False positive rate < 5%
- User feedback indicates clear, actionable reports

---

**End of Document**
