fix: complete ebay integer validation test coverage

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

@@ -36,14 +36,7 @@ export function parseNonNegativeIntegerParam(
       { status: 400 },
     );
   }
-  const value = Number(rawValue);
-  if (value < 0) {
-    return Response.json(
-      { message: `Invalid ${name} parameter` },
-      { status: 400 },
-    );
-  }
-  return value;
+  return Number(rawValue);
 }
 
 export function emptySearchResponse(): Response {