add unit test for NestedUtils

src/DataTypes/tests/gtest_NestedUtils.cpp

@@ -0,0 +1,43 @@
+#include <DataTypes/NestedUtils.h>
+#include <DataTypes/DataTypesNumber.h>
+#include <DataTypes/DataTypeArray.h>
+#include <DataTypes/DataTypeNested.h>
+#include <gtest/gtest.h>
+
+using namespace DB;
+
+GTEST_TEST(NestedUtils, collect)
+{
+    DataTypePtr uint_type = std::make_shared<DataTypeUInt32>();
+    DataTypePtr array_type = std::make_shared<DataTypeArray>(std::make_shared<DataTypeUInt32>());
+
+    const NamesAndTypesList source_columns =
+    {
+        {"id", uint_type},
+        {"arr1", array_type},
+        {"b.id", uint_type},
+        {"b.arr1", array_type},
+        {"b.arr2", array_type}
+    };
+
+    auto nested_type = createNested({uint_type, uint_type}, {"arr1", "arr2"});
+    const NamesAndTypesList columns_with_subcolumns =
+    {
+        {"id", uint_type},
+        {"arr1", array_type},
+        {"b.id", uint_type},
+        {"b", "arr1", nested_type, array_type},
+        {"b", "arr2", nested_type, array_type}
+    };
+
+    const NamesAndTypesList columns_with_nested =
+    {
+        {"id", uint_type},
+        {"arr1", array_type},
+        {"b.id", uint_type},
+        {"b", nested_type},
+    };
+
+    ASSERT_EQ(Nested::convertToSubcolumns(source_columns).toString(), columns_with_subcolumns.toString());
+    ASSERT_EQ(Nested::collect(source_columns).toString(), columns_with_nested.toString());
+}