[metric][fix]to_json for empty vector (#838)

alibaba · Dec 3, 2024 · c902933 · c902933
1 parent 40f6cf7
commit c902933
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Showing 2 changed files with 6 additions and 6 deletions.
diff --git a/include/ylt/metric/metric_manager.hpp b/include/ylt/metric/metric_manager.hpp
@@ -37,9 +37,6 @@ class manager_helper {
 #ifdef CINATRA_ENABLE_METRIC_JSON
   static std::string serialize_to_json(
       const std::vector<std::shared_ptr<metric_t>>& metrics) {
-    if (metrics.empty()) {
-      return "";
-    }
     std::string str;
     str.append("[");
     for (auto& m : metrics) {
@@ -50,7 +47,10 @@ class manager_helper {
     }
 
     if (str.size() == 1) {
-      return "";
+      str.append("]");
+    }
+    else {
+      str.back() = ']';
     }
 
     str.back() = ']';

diff --git a/src/metric/tests/test_metric.cpp b/src/metric/tests/test_metric.cpp
@@ -1155,12 +1155,12 @@ TEST_CASE("test filter metrics static") {
 #ifdef CINATRA_ENABLE_METRIC_JSON
     std::vector<std::shared_ptr<metric_t>> vec{};
     auto s = manager_helper::serialize_to_json(vec);
-    CHECK(s.empty());
+    CHECK(s == "[]");
     auto c = std::make_shared<counter_t>(std::string("get_count"),
                                          std::string("get counter"));
     vec.push_back(c);
     s = manager_helper::serialize_to_json(vec);
-    CHECK(s.empty());
+    CHECK(s == "[]");
 #endif
   }