Fixed test for ColumnDecimal::GetItem

Author: Enmk

ut/Column_ut.cpp

@@ -152,10 +152,14 @@ TYPED_TEST(GenericColumnTest, Append) {
 
 // To make some value types compatitable with Column::GetItem()
 template <typename ColumnType, typename ValueType>
-inline auto convertValueForGetItem(ValueType&& t) {
+inline auto convertValueForGetItem(const ColumnType& col, ValueType&& t) {
     using T = std::remove_cv_t<std::decay_t<ValueType>>;
 
-    if constexpr (std::is_same_v<T, clickhouse::UInt128>
+    if constexpr (std::is_same_v<ColumnType, ColumnDecimal>) {
+            // Since ColumnDecimal can hold 32, 64, 128-bit wide data and there is no way telling at run-time.
+            const ItemView item = col.GetItem(0);
+        return std::string_view(reinterpret_cast<const char*>(&t), item.data.size());
+    } else if constexpr (std::is_same_v<T, clickhouse::UInt128>
             || std::is_same_v<T, clickhouse::Int128>) {
         return std::string_view{reinterpret_cast<const char*>(&t), sizeof(T)};
     } else if constexpr (std::is_same_v<T, in_addr>) {
@@ -178,7 +182,7 @@ TYPED_TEST(GenericColumnTest, GetItem) {
     ASSERT_EQ(column->GetItem(0).type, column->GetType().GetCode());
 
     for (size_t i = 0; i < values.size(); ++i) {
-        const auto v = convertValueForGetItem<typename TestFixture::ColumnType>(values[i]);
+        const auto v = convertValueForGetItem(*column, values[i]);
         const ItemView item = column->GetItem(i);
 
         ASSERT_TRUE(CompareRecursive(item.get<decltype(v)>(), v));