From 42e351878d99d5f1009d1b309c57a7aa3261b48b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javier=20Jaramago=20Fern=C3=A1ndez?=
 <jaramago.fernandez.javier@gmail.com>
Date: Thu, 24 Jun 2021 11:57:33 +0200
Subject: [PATCH] Added regression test for added support to comments in 'USE'
 statements #3493

---
 .../reg_test_3493-USE_with_comment-t.cpp      | 106 ++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 test/tap/tests/reg_test_3493-USE_with_comment-t.cpp

diff --git a/test/tap/tests/reg_test_3493-USE_with_comment-t.cpp b/test/tap/tests/reg_test_3493-USE_with_comment-t.cpp
new file mode 100644
index 000000000..5c412387e
--- /dev/null
+++ b/test/tap/tests/reg_test_3493-USE_with_comment-t.cpp
@@ -0,0 +1,106 @@
+/**
+ * @file reg_test_3493-USE_with_comment-t.cpp
+ * @brief This test verifies that a 'USE' statement is properly tracked by
+ *   ProxySQL, even when executed with a leading comment.
+ * @details For being sure that the feature is properly supported the
+ *   test performs the following actions:
+ *
+ *   1. Open a MYSQL connection to ProxySQL.
+ *   2. Drops and creates a new database called 'reg_test_3493_use_comment'.
+ *   3. Checks the currently selected database in **a new backend database
+ *      connection** by means of the connection annotation
+ *      "create_new_connection=1". This way it's ensured that ProxySQL is
+ *      properly keeping track of the database selected in the issued 'USE'
+ *      statement.
+ */
+
+#include <cstring>
+#include <vector>
+#include <string>
+#include <stdio.h>
+
+#include <mysql.h>
+
+#include "tap.h"
+#include "command_line.h"
+#include "utils.h"
+#include "json.hpp"
+
+using nlohmann::json;
+
+void parse_result_json_column(MYSQL_RES *result, json& j) {
+	if(!result) return;
+	MYSQL_ROW row;
+
+	while ((row = mysql_fetch_row(result))) {
+		j = json::parse(row[0]);
+	}
+}
+
+int main(int argc, char** argv) {
+	CommandLine cl;
+
+	if (cl.getEnv()) {
+		diag("Failed to get the required environmental variables.");
+		return -1;
+	}
+
+	MYSQL* proxysql_mysql = mysql_init(NULL);
+
+	if (
+		!mysql_real_connect(
+			proxysql_mysql, cl.host, cl.username, cl.password, NULL, cl.port, NULL, 0
+		)
+	) {
+		fprintf(
+			stderr, "File %s, line %d, Error: %s\n", __FILE__, __LINE__,
+			mysql_error(proxysql_mysql)
+		);
+		return EXIT_FAILURE;
+	}
+
+	// Prepare the DB for the test
+	MYSQL_QUERY(proxysql_mysql, "DROP DATABASE IF EXISTS reg_test_3493_use_comment");
+	MYSQL_QUERY(proxysql_mysql, "CREATE DATABASE reg_test_3493_use_comment");
+
+	int err = mysql_query(proxysql_mysql, "/*+ placeholder_comment */ USE reg_test_3493_use_comment");
+	if (err) {
+		diag(
+			"'USE' command failed with error code '%d' and error '%s'",
+			err, mysql_error(proxysql_mysql)
+		);
+		return EXIT_FAILURE;
+	}
+
+	// Perform the 'SELECT DATABASE()' query in a new backend connection, to
+	// verify that ProxySQL is properly tracking the previously performed 'USE'
+	// statement.
+	MYSQL_QUERY(proxysql_mysql, "/*+ ;create_new_connection=1 */ SELECT DATABASE()");
+	MYSQL_RES* result = mysql_store_result(proxysql_mysql);
+	if (result == nullptr) {
+		diag("Invalid 'MYSQL_RES' returned from 'SELECT DATABASE()'");
+		return EXIT_FAILURE;
+	}
+
+	MYSQL_ROW row = mysql_fetch_row(result);
+	if (row == nullptr) {
+		diag("Invalid 'MYSQL_ROW' returned from 'SELECT DATABASE()'");
+		return EXIT_FAILURE;
+	}
+
+	std::string database_name { row[0] };
+
+	ok(
+		database_name == "reg_test_3493_use_comment",
+		"Selected DB name should be equal to actual DB name: (Exp: '%s') == (Act: '%s')",
+		"reg_test_3493_use_comment",
+		database_name.c_str()
+	);
+
+	// Drop created database
+	MYSQL_QUERY(proxysql_mysql, "DROP DATABASE IF EXISTS reg_test_3493_use_comment");
+
+	mysql_close(proxysql_mysql);
+
+	return exit_status();
+}