Implement Core Performance Testing Engine (Phase 1 & 2)

- Added Lighthouse and Chrome Launcher dependencies
- Created lib/runner.js test runner service
- Implemented filesystem storage for test results
- Added API endpoints: POST /api/run-test and GET /api/history

lib/runner.js

@@ -0,0 +1,113 @@
+const lighthouse = require('lighthouse');
+const chromeLauncher = require('chrome-launcher');
+const fs = require('fs');
+const path = require('path');
+const { v4: uuidv4 } = require('uuid');
+
+/**
+ * Run a performance test using Lighthouse
+ * @param {string} url - The URL to test
+ * @param {object} options - Configuration options (mobile vs desktop, etc.)
+ * @returns {Promise<object>} - Test results
+ */
+async function runTest(url, options = {}) {
+  const isMobile = options.isMobile ?? true; // Default to mobile
+  const reportDir = path.join(__dirname, '..', 'reports');
+
+  // Ensure reports directory exists
+  if (!fs.existsSync(reportDir)) {
+    fs.mkdirSync(reportDir, { recursive: true });
+  }
+
+  // Launch Chrome
+  const chrome = await chromeLauncher.launch({ chromeFlags: ['--headless'] });
+  
+  // Lighthouse Config
+  const port = chrome.port;
+  const config = {
+    extends: 'lighthouse:default',
+    settings: {
+      onlyCategories: ['performance', 'accessibility', 'best-practices', 'seo'],
+      formFactor: isMobile ? 'mobile' : 'desktop',
+      screenEmulation: isMobile 
+        ? undefined // Uses default mobile emulation
+        : { mobile: false, width: 1350, height: 940, deviceScaleFactor: 1, disabled: false },
+    },
+  };
+
+  const runnerOptions = {
+    logLevel: 'info',
+    output: 'html',
+    onlyCategories: ['performance', 'accessibility', 'best-practices', 'seo'],
+    port: port,
+  };
+
+  const testId = uuidv4();
+  
+  try {
+    const runnerResult = await lighthouse(url, runnerOptions, config);
+
+    // Save HTML Report
+    const reportHtml = runnerResult.report;
+    const reportPath = path.join(reportDir, `${testId}.html`);
+    fs.writeFileSync(reportPath, reportHtml);
+
+    // Prepare JSON Summary
+    const lhr = runnerResult.lhr;
+    const summary = {
+      id: testId,
+      url: lhr.finalUrl,
+      timestamp: lhr.fetchTime,
+      scores: {
+        performance: lhr.categories.performance.score * 100,
+        accessibility: lhr.categories.accessibility.score * 100,
+        bestPractices: lhr.categories['best-practices'].score * 100,
+        seo: lhr.categories.seo.score * 100,
+      },
+      metrics: {
+        lcp: lhr.audits['largest-contentful-paint'].numericValue,
+        cls: lhr.audits['cumulative-layout-shift'].numericValue,
+        tbt: lhr.audits['total-blocking-time'].numericValue,
+      },
+      userAgent: lhr.userAgent,
+      isMobile: isMobile
+    };
+
+    // Save JSON Summary
+    const jsonPath = path.join(reportDir, `${testId}.json`);
+    fs.writeFileSync(jsonPath, JSON.stringify(summary, null, 2));
+
+    await chrome.kill();
+
+    return summary;
+
+  } catch (error) {
+    if (chrome) await chrome.kill();
+    throw error;
+  }
+}
+
+/**
+ * Get list of all test results
+ */
+function getHistory() {
+  const reportDir = path.join(__dirname, '..', 'reports');
+  if (!fs.existsSync(reportDir)) return [];
+
+  const files = fs.readdirSync(reportDir).filter(f => f.endsWith('.json'));
+  const history = files.map(file => {
+    try {
+      return JSON.parse(fs.readFileSync(path.join(reportDir, file), 'utf8'));
+    } catch (e) {
+      return null;
+    }
+  }).filter(Boolean);
+
+  // Sort by newest first
+  return history.sort((a, b) => new Date(b.timestamp) - new Date(a.timestamp));
+}
+
+module.exports = {
+  runTest,
+  getHistory
+};