chore: increase the coverage in BasicKV

tests/BasicKVTest.cpp

@@ -133,4 +133,30 @@ TEST_F(BasicKVTest, BasicKVInsertAndLookup) {
   });
 }
 
+TEST_F(BasicKVTest, BasicKVInsertDuplicatedKey) {
+  // create leanstore btree for table records
+  storage::btree::BasicKV* btree;
+  const auto* btreeName = "testTree1";
+
+   std::string key("key_btree_LL_xxxxxxxxxxxx_");
+   std::string val("VAL_BTREE_LL_YYYYYYYYYYYY_");
+
+  mStore->ExecSync(0, [&]() {
+    auto res = mStore->CreateBasicKV(btreeName);
+    EXPECT_TRUE(res);
+    EXPECT_NE(res.value(), nullptr);
+
+    btree = res.value();
+    cr::Worker::My().StartTx();
+    EXPECT_EQ(btree->Insert(Slice((const uint8_t*)key.data(), key.size()),
+                            Slice((const uint8_t*)val.data(), val.size())),
+              OpCode::kOK);
+    EXPECT_EQ(btree->Insert(Slice((const uint8_t*)key.data(), key.size()),
+                            Slice((const uint8_t*)val.data(), val.size())),
+              OpCode::kDuplicated);
+    cr::Worker::My().CommitTx();
+  });
+}
+
+
 } // namespace leanstore::test