Added unit tests for column_type

test/unit/CMakeLists.txt

@@ -104,6 +104,7 @@ add_executable(
     test/resultset_view.cpp
     test/resultset.cpp
     test/client_errc.cpp
+    test/column_type.cpp
     test/common_server_errc.cpp
     test/mysql_server_errc.cpp
     test/mariadb_server_errc.cpp

test/unit/Jamfile

@@ -113,6 +113,7 @@ run
         test/resultset_view.cpp
         test/resultset.cpp
         test/client_errc.cpp
+        test/column_type.cpp
         test/common_server_errc.cpp
         test/mysql_server_errc.cpp
         test/mariadb_server_errc.cpp

test/unit/test/column_type.cpp

@@ -0,0 +1,80 @@
+//
+// Copyright (c) 2026 Vladislav Soulgard (vsoulgard at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#include <boost/mysql/column_type.hpp>
+
+#include <boost/test/unit_test.hpp>
+
+#include <string>
+#include <sstream>
+#include <iostream>
+
+using namespace boost::mysql;
+
+BOOST_AUTO_TEST_SUITE(test_column_type)
+
+std::string to_string(column_type t)
+{
+    std::ostringstream oss;
+    auto& result = oss << t;
+    BOOST_TEST(!oss.fail());
+    // Check if operator<< return same stream object
+    BOOST_TEST(&result == &oss);
+    return oss.str();
+}
+
+BOOST_AUTO_TEST_CASE(stream_operator_basic)
+{
+    // Numeric types
+    BOOST_TEST(to_string(column_type::tinyint) == "tinyint");
+    BOOST_TEST(to_string(column_type::smallint) == "smallint");
+    BOOST_TEST(to_string(column_type::mediumint) == "mediumint");
+    BOOST_TEST(to_string(column_type::int_) == "int_");
+    BOOST_TEST(to_string(column_type::bigint) == "bigint");
+
+    // Floating-point types
+    BOOST_TEST(to_string(column_type::float_) == "float_");
+    BOOST_TEST(to_string(column_type::double_) == "double_");
+    BOOST_TEST(to_string(column_type::decimal) == "decimal");
+
+    // Special types
+    BOOST_TEST(to_string(column_type::bit) == "bit");
+    BOOST_TEST(to_string(column_type::year) == "year");
+
+    // Date/time types
+    BOOST_TEST(to_string(column_type::time) == "time");
+    BOOST_TEST(to_string(column_type::date) == "date");
+    BOOST_TEST(to_string(column_type::datetime) == "datetime");
+    BOOST_TEST(to_string(column_type::timestamp) == "timestamp");
+
+    // String types
+    BOOST_TEST(to_string(column_type::char_) == "char_");
+    BOOST_TEST(to_string(column_type::varchar) == "varchar");
+    BOOST_TEST(to_string(column_type::binary) == "binary");
+    BOOST_TEST(to_string(column_type::varbinary) == "varbinary");
+
+    // Large object types
+    BOOST_TEST(to_string(column_type::text) == "text");
+    BOOST_TEST(to_string(column_type::blob) == "blob");
+
+    // Special MySQL types
+    BOOST_TEST(to_string(column_type::enum_) == "enum_");
+    BOOST_TEST(to_string(column_type::set) == "set");
+    BOOST_TEST(to_string(column_type::json) == "json");
+    BOOST_TEST(to_string(column_type::geometry) == "geometry");
+}
+
+BOOST_AUTO_TEST_CASE(stream_operator_unknown)
+{
+    // Unknown type
+    BOOST_TEST(to_string(column_type::unknown) == "<unknown column type>");
+
+    // Incorrect value
+    BOOST_TEST(to_string(static_cast<column_type>(999)) == "<unknown column type>");
+}
+
+BOOST_AUTO_TEST_SUITE_END()