scoring.ts•1.57 kB
/**
* Helpers for reasoning about Lighthouse scoring weights.
*
* The logic mirrors the default Lighthouse scoring implementation
* (see tmp/lighthouse/core/scoring.js and default-config auditRefs).
*/
import type { LighthouseReport } from '../types/index.js';
export interface AuditWeightInfo {
categoryId: string;
weight: number;
normalizedWeight: number;
}
/**
* Build a lookup of audit weights keyed by audit id.
*/
export function buildAuditWeightIndex(report: LighthouseReport): Record<string, AuditWeightInfo> {
const index: Record<string, AuditWeightInfo> = {};
if (!report?.categories) {
return index;
}
for (const [categoryId, category] of Object.entries(report.categories)) {
const auditRefs = category?.auditRefs || [];
if (!Array.isArray(auditRefs) || auditRefs.length === 0) {
continue;
}
const totalWeight = auditRefs
.map(ref => ref.weight || 0)
.filter(weight => weight > 0)
.reduce((sum, weight) => sum + weight, 0);
for (const ref of auditRefs) {
const rawWeight = ref.weight || 0;
const normalizedWeight = totalWeight > 0 && rawWeight > 0 ? rawWeight / totalWeight : 0;
index[ref.id] = {
categoryId,
weight: rawWeight,
normalizedWeight,
};
}
}
return index;
}
/**
* Retrieve weight information for a specific audit.
*/
export function getAuditWeightInfo(
report: LighthouseReport,
auditId: string,
): AuditWeightInfo | undefined {
const index = buildAuditWeightIndex(report);
return index[auditId];
}