Add LC of nullable UT

Author: arthurpassos

ut/low_cardinality_nullable_tests.cpp

@@ -0,0 +1,116 @@
+#include <gtest/gtest.h>
+#include <clickhouse/columns/string.h>
+#include "clickhouse/columns/nullable.h"
+#include "clickhouse/columns/lowcardinality.h"
+#include "clickhouse/client.h"
+#include "utils.h"
+#include "clickhouse/base/wire_format.h"
+#include <clickhouse/base/output.h>
+
+namespace
+{
+using namespace clickhouse;
+}
+
+static const auto localHostEndpoint = ClientOptions()
+                                   .SetHost(           getEnvOrDefault("CLICKHOUSE_HOST",     "localhost"))
+                                   .SetPort(   getEnvOrDefault<size_t>("CLICKHOUSE_PORT",     "9000"))
+                                   .SetUser(           getEnvOrDefault("CLICKHOUSE_USER",     "default"))
+                                   .SetPassword(       getEnvOrDefault("CLICKHOUSE_PASSWORD", ""))
+                                   .SetDefaultDatabase(getEnvOrDefault("CLICKHOUSE_DB",       "default"));
+
+
+ColumnRef buildTestColumn(const std::vector<std::string>& rowsData, const std::vector<uint8_t>& nulls) {
+    auto stringColumn = std::make_shared<ColumnString>(rowsData);
+    auto nullsColumn = std::make_shared<ColumnUInt8>(nulls);
+    auto lowCardinalityColumn = std::make_shared<ColumnLowCardinality>(
+        std::make_shared<ColumnNullable>(stringColumn, nullsColumn)
+    );
+
+    return lowCardinalityColumn;
+}
+
+void createTable(Client& client) {
+    client.Execute("DROP TEMPORARY TABLE IF EXISTS lc_of_nullable");
+    client.Execute("CREATE TEMPORARY TABLE IF NOT EXISTS lc_of_nullable (words LowCardinality(Nullable(String))) ENGINE = Memory");
+}
+
+TEST(LowCardinalityOfNullable, InsertAndQuery) {
+    const auto rowsData = std::vector<std::string> {
+        "eminem",
+        "",
+        "tupac",
+        "shady",
+        "fifty",
+        "dre",
+        "",
+        "cube"
+    };
+
+    const auto nulls = std::vector<uint8_t> {
+        false, false, true, false, true, true, false, false
+    };
+
+    auto column = buildTestColumn(rowsData, nulls);
+
+    Block block;
+    block.AppendColumn("words", column);
+
+    Client client(ClientOptions(localHostEndpoint)
+                             .SetBakcwardCompatibilityFeatureLowCardinalityAsWrappedColumn(false)
+                             .SetPingBeforeQuery(true));
+
+    createTable(client);
+
+    client.Insert("lc_of_nullable", block);
+
+    client.Select("SELECT * FROM lc_of_nullable", [&](const Block& bl) {
+        for (size_t row = 0; row < bl.GetRowCount(); row++) {
+            auto lc_col = bl[0]->As<ColumnLowCardinality>();
+            auto item = lc_col->GetItem(row);
+
+            if (nulls[row]) {
+                ASSERT_EQ(Type::Code::Void, item.type);
+            } else {
+                ASSERT_EQ(rowsData[row], item.get<std::string_view>());
+            }
+        }
+    });
+}
+
+TEST(LowCardinalityOfNullable, InsertAndQueryEmpty) {
+    auto column = buildTestColumn({}, {});
+
+    Block block;
+    block.AppendColumn("words", column);
+
+    Client client(ClientOptions(localHostEndpoint)
+                      .SetBakcwardCompatibilityFeatureLowCardinalityAsWrappedColumn(false)
+                      .SetPingBeforeQuery(true));
+
+    createTable(client);
+
+    EXPECT_NO_THROW(client.Insert("lc_of_nullable", block));
+
+    client.Select("SELECT * FROM lc_of_nullable", [&](const Block& bl) {
+        ASSERT_EQ(bl.GetRowCount(), 0u);
+    });
+}
+
+TEST(LowCardinalityOfNullable, ThrowOnBackwardsCompatibleLCColumn) {
+    auto column = buildTestColumn({}, {});
+
+    Block block;
+    block.AppendColumn("words", column);
+
+    Client client(ClientOptions(localHostEndpoint)
+                      .SetPingBeforeQuery(true));
+
+    createTable(client);
+
+    EXPECT_THROW(client.Insert("lc_of_nullable", block), UnimplementedError);
+
+    client.Select("SELECT * FROM lc_of_nullable", [&](const Block& bl) {
+        ASSERT_EQ(bl.GetRowCount(), 0u);
+    });
+}