patterns.ts•1.94 kB
import type { LighthouseReport, Pattern } from '../types';
/**
* Detect patterns in Lighthouse report
*/
export function detectPatterns(report: LighthouseReport): Pattern[] {
const patterns: Pattern[] = [];
if (!report || !report.audits) {
return patterns;
}
// Check for common performance patterns
const audits = report.audits;
// Large JavaScript pattern
const bootupAudit = audits['bootup-time'];
if (typeof bootupAudit?.score === 'number' && bootupAudit.score < 0.5) {
patterns.push({
id: 'large-javascript',
name: 'Large JavaScript Bundles',
confidence: 0.8,
indicators: ['High JavaScript execution time', 'Large bundle sizes'],
recommendations: [
'Code split your JavaScript bundles',
'Remove unused code',
'Minimize and compress JavaScript files'
]
});
}
// Unoptimized images pattern
const optimizedImagesAudit = audits['uses-optimized-images'];
if (typeof optimizedImagesAudit?.score === 'number' && optimizedImagesAudit.score < 0.5) {
patterns.push({
id: 'unoptimized-images',
name: 'Unoptimized Images',
confidence: 0.9,
indicators: ['Large image file sizes', 'Missing modern formats'],
recommendations: [
'Use WebP or AVIF formats',
'Implement responsive images',
'Compress images properly'
]
});
}
// Render blocking resources pattern
const renderBlockingAudit = audits['render-blocking-resources'];
if (typeof renderBlockingAudit?.score === 'number' && renderBlockingAudit.score < 0.5) {
patterns.push({
id: 'render-blocking',
name: 'Render Blocking Resources',
confidence: 0.85,
indicators: ['Blocking CSS', 'Blocking JavaScript in head'],
recommendations: [
'Inline critical CSS',
'Defer non-critical JavaScript',
'Use async/defer attributes'
]
});
}
return patterns;
}