return empty if query is null

src/main/java/com/danielbohry/stocks/service/StockService.java

@@ -8,6 +8,8 @@ import org.springframework.stereotype.Service;
 
 import java.util.List;
 
+import static java.util.Collections.emptyList;
+
 @Slf4j
 @Service
 @AllArgsConstructor
@@ -16,9 +18,11 @@ public class StockService {
     private StockRepository repository;
 
     public List<Quote> get(String query) {
-        return query == null
-                ? repository.findAll()
-                : repository.findLike(query);
+        if (query == null) {
+            return emptyList();
+        }
+
+        return repository.findLike(query);
     }
 
     public Quote getByCode(String code) {