Initial commit

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F22Ms5Cxam5UHyxaCrtZzu

lib/url-params.ts

@@ -0,0 +1,20 @@
+/**
+ * Adapt a Next.js App Router `searchParams` record (`Record<string, string |
+ * string[] | undefined>`) into a `URLSearchParams` for Hydrogen helpers that
+ * expect a `URLSearchParams` (`getSelectedProductOptions`, `parseCollectionParams`).
+ *
+ * `searchParams` is a `Promise<Record<...>>` in Next 15+ — `await` it first.
+ */
+export function toURLSearchParams(
+  input: Record<string, string | string[] | undefined>,
+): URLSearchParams {
+  const params = new URLSearchParams();
+  for (const [key, value] of Object.entries(input)) {
+    if (Array.isArray(value)) {
+      for (const item of value) params.append(key, item);
+    } else if (value != null) {
+      params.set(key, value);
+    }
+  }
+  return params;
+}