core: reject duplicate label names (#463)

Issue: #459
jupp0r · Mar 8, 2021 · 77b06a8 · 77b06a8
1 parent d095854
commit 77b06a8
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Showing 2 changed files with 10 additions and 0 deletions.
diff --git a/core/src/family.cc b/core/src/family.cc
@@ -52,6 +52,9 @@ T& Family<T>::Add(const std::map<std::string, std::string>& labels,
     if (!CheckLabelName(label_name)) {
       throw std::invalid_argument("Invalid label name");
     }
+    if (constant_labels_.count(label_name)) {
+      throw std::invalid_argument("Duplicate label name");
+    }
   }
 
   auto metric = metrics_.insert(std::make_pair(hash, std::move(object)));

diff --git a/core/tests/family_test.cc b/core/tests/family_test.cc
@@ -28,6 +28,13 @@ TEST(FamilyTest, labels) {
               ::testing::ElementsAre(const_label, dynamic_label));
 }
 
+TEST(FamilyTest, reject_same_label_keys) {
+  auto labels = std::map<std::string, std::string>{{"component", "test"}};
+
+  Family<Counter> family{"total_requests", "Counts all requests", labels};
+  EXPECT_ANY_THROW(family.Add(labels));
+}
+
 TEST(FamilyTest, counter_value) {
   Family<Counter> family{"total_requests", "Counts all requests", {}};
   auto& counter = family.Add({});