Migrate from psl to tldts for public suffix detection

src/lib/domain.test.ts

@@ -1,9 +1,9 @@
 import { expect, test } from "vitest";
-import { extractTld, isLikelyDomain } from "./domain";
+import { getDomainParts, isLikelyDomain } from "./domain";
 
-test("extractTld basic", () => {
-  expect(extractTld("example.com")).toBe("com");
-  expect(extractTld("sub.example.co.uk")).toBe("uk");
+test("getDomainParts.tld basic", () => {
+  expect(getDomainParts("example.com").tld).toBe("com");
+  expect(getDomainParts("sub.example.co.uk").tld).toBe("uk");
 });
 
 test("isLikelyDomain", () => {

src/lib/domain.ts

@@ -1,37 +1,13 @@
-import psl from "psl";
-
-export function extractTld(domain: string): string {
-  const lower = domain.trim().toLowerCase();
-  try {
-    const parsed = psl.parse?.(lower) as { tld?: string };
-    const suffix = parsed?.tld;
-    if (suffix) {
-      const labels = String(suffix).split(".").filter(Boolean);
-      if (labels.length) return labels[labels.length - 1];
-    }
-  } catch {
-    // ignore and fall back
-  }
-  const parts = lower.split(".").filter(Boolean);
-  return parts[parts.length - 1] ?? lower;
-}
+import { getPublicSuffix } from "tldts";
 
 export function getDomainParts(domain: string): {
   publicSuffix: string;
   tld: string;
 } {
   const lower = domain.toLowerCase().trim();
-  let publicSuffix: string | undefined;
-  try {
-    const parsed = psl.parse?.(lower) as { tld?: string };
-    publicSuffix = parsed?.tld;
-  } catch {
-    // ignore
-  }
-  if (!publicSuffix) {
-    const parts = lower.split(".").filter(Boolean);
-    publicSuffix = parts.length ? parts[parts.length - 1] : lower;
-  }
+  const suffix = getPublicSuffix(lower) || "";
+  const publicSuffix =
+    suffix || lower.split(".").filter(Boolean).pop() || lower;
   const labels = publicSuffix.split(".").filter(Boolean);
   const tld = labels.length ? labels[labels.length - 1] : publicSuffix;
   return { publicSuffix, tld };