novalon-website/test-framework/shared/utils/reporting/PerformanceBaseline.ts

import { TestResult, PerformanceMetrics, ComparisonResult, PerformanceBaseline as PerformanceBaselineType } from '../../types/reporting';

export class PerformanceBaseline {
  private baseline: Map<string, PerformanceMetrics> = new Map();

  calculate(results: TestResult[]): PerformanceBaselineType {
    results.forEach(result => {
      if (result.type === 'performance' && result.metrics) {
        this.updateBaseline(result);
      }
    });
    
    const firstBaseline = this.baseline.values().next().value;
    return {
      timestamp: Date.now(),
      metrics: firstBaseline || {
        loadTime: 0,
        domContentLoaded: 0,
        firstContentfulPaint: 0,
        largestContentfulPaint: 0,
        cumulativeLayoutShift: 0,
        firstInputDelay: 0
      },
      url: ''
    };
  }

  private updateBaseline(result: TestResult): void {
    const key = result.name;
    const current = this.baseline.get(key);
    const metrics = result.metrics as PerformanceMetrics;

    if (!current || metrics.loadTime < current.loadTime) {
      this.baseline.set(key, metrics);
    }
  }

  compareWithBaseline(metrics: PerformanceMetrics, testName: string): ComparisonResult {
    const baseline = this.baseline.get(testName);
    if (!baseline) {
      return { status: 'no-baseline', difference: 0 };
    }

    const difference = metrics.loadTime - baseline.loadTime;
    const status = difference > 500 ? 'regression' : difference < -500 ? 'improvement' : 'stable';

    return { status, difference };
  }

  getBaseline(testName: string): PerformanceMetrics | undefined {
    return this.baseline.get(testName);
  }

  getAllBaselines(): Map<string, PerformanceMetrics> {
    return this.baseline;
  }
}