Initial curated CertScope source from fe2bbe3ca5c98bf64be26a09c6c58ee805a7f87e

lib/inspect/score.ts

@@ -0,0 +1,22 @@
+import type { Category, Finding, InspectionScore } from "./types";
+
+const CATEGORY_ORDER: Category[] = ["dns", "tls", "http"];
+
+function clamp(value: number) {
+  return Math.max(0, Math.min(100, Math.round(value)));
+}
+
+/**
+ * Scores are calculated per category first, then averaged equally. This keeps
+ * one category's findings from being charged again against the global score.
+ */
+export function score(findings: Finding[]): InspectionScore {
+  const categories: Record<Category, number> = { dns: 100, tls: 100, http: 100 };
+  for (const finding of findings) {
+    const impact = Number.isFinite(finding.scoreImpact) ? Math.min(0, finding.scoreImpact) : 0;
+    categories[finding.category] = clamp(categories[finding.category] + impact);
+  }
+
+  const overall = clamp(CATEGORY_ORDER.reduce((sum, category) => sum + categories[category], 0) / CATEGORY_ORDER.length);
+  return { overall, deductions: 100 - overall, categories };
+}