fix: align ebay route with spec and validate params

packages/api-server/src/routes/kijiji.ts

@@ -19,10 +19,28 @@ export async function kijijiRoute(req: Request): Promise<Response> {
 
   const maxPagesParam = reqUrl.searchParams.get("maxPages");
   const maxPages = maxPagesParam ? parseInt(maxPagesParam, 10) : 5;
+  if (maxPagesParam && Number.isNaN(maxPages)) {
+    return Response.json(
+      { message: "Invalid maxPages parameter" },
+      { status: 400 },
+    );
+  }
   const priceMinParam = reqUrl.searchParams.get("priceMin");
   const priceMin = priceMinParam ? parseInt(priceMinParam, 10) : undefined;
+  if (priceMinParam && Number.isNaN(priceMin)) {
+    return Response.json(
+      { message: "Invalid priceMin parameter" },
+      { status: 400 },
+    );
+  }
   const priceMaxParam = reqUrl.searchParams.get("priceMax");
   const priceMax = priceMaxParam ? parseInt(priceMaxParam, 10) : undefined;
+  if (priceMaxParam && Number.isNaN(priceMax)) {
+    return Response.json(
+      { message: "Invalid priceMax parameter" },
+      { status: 400 },
+    );
+  }
   const hideUnstableResults =
     reqUrl.searchParams.get("unstableFilter") === "true";