1 files changed, 30 insertions, 0 deletions
diff --git a/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp b/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp
index ee1680bbd9a..5ddbb6d0a11 100644
--- a/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp
+++ b/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp
@@ -157,6 +157,12 @@ public:
     void expect_empty_add() const {
         EXPECT_TRUE(_adds.empty());
     }
+    void expect_empty_prepare_add() const {
+        EXPECT_TRUE(_prepare_adds.empty());
+    }
+    void expect_empty_complete_add() const {
+        EXPECT_TRUE(_complete_adds.empty());
+    }
     void expect_entry(uint32_t exp_docid, const DoubleVector& exp_vector, const EntryVector& entries) const {
         EXPECT_EQUAL(1u, entries.size());
         EXPECT_EQUAL(exp_docid, entries.back().first);
@@ -881,6 +887,30 @@ TEST_F("nearest neighbor index can be updated in two phases", DenseTensorAttribu
     }
 }
 
+TEST_F("nearest neighbor index is NOT updated when tensor value is unchanged", DenseTensorAttributeMockIndex)
+{
+    auto& index = f.mock_index();
+    {
+        auto vec_a = vec_2d(3, 5);
+        auto prepare_result = f.prepare_set_tensor(1, vec_a);
+        index.expect_prepare_add(1, {3, 5});
+        f.complete_set_tensor(1, vec_a, std::move(prepare_result));
+        f.assertGetTensor(vec_a, 1);
+        index.expect_complete_add(1, {3, 5});
+    }
+    index.clear();
+    {
+        // Replaces previous value with the same value
+        auto vec_b = vec_2d(3, 5);
+        auto prepare_result = f.prepare_set_tensor(1, vec_b);
+        EXPECT_TRUE(prepare_result.get() == nullptr);
+        index.expect_empty_prepare_add();
+        f.complete_set_tensor(1, vec_b, std::move(prepare_result));
+        f.assertGetTensor(vec_b, 1);
+        index.expect_empty_complete_add();
+    }
+}
+
 TEST_F("clearDoc() updates nearest neighbor index", DenseTensorAttributeMockIndex)
 {
     auto& index = f.mock_index();