test: Add descriptive diagnostics to mysql-sql_log_bin-error-t.cpp

test/tap/tests/mysql-sql_log_bin-error-t.cpp

@@ -18,6 +18,13 @@ int main(int argc, char** argv) {
 	if(cl.getEnv())
 		return exit_status();
 
+	diag("Test: mysql-sql_log_bin-error-t");
+	diag("This test verifies ProxySQL's behavior when an unprivileged user");
+	diag("attempts to execute 'SET sql_log_bin=0'.");
+	diag("The test expects that this unauthorized action should lead to a failure");
+	diag("in the subsequent query, likely because the connection should be terminated");
+	diag("or an error state should be triggered.");
+
 	spawn_internal_noise(cl, internal_noise_random_stats_poller);
 	spawn_internal_noise(cl, internal_noise_rest_prometheus_poller, {{"enable_rest_api", "true"}});
 	spawn_internal_noise(cl, internal_noise_pgsql_traffic_v2, {{"num_connections", "100"}, {"reconnect_interval", "100"}, {"avg_delay_ms", "300"}});
@@ -32,17 +39,32 @@ int main(int argc, char** argv) {
 	if (!mysql)
 		return exit_status();
 
+	diag("Connecting to ProxySQL as unprivileged user 'sbtest1'...");
 	if (!mysql_real_connect(mysql, cl.host, "sbtest1", "sbtest1", NULL, cl.port, NULL, 0)) {
 	    fprintf(stderr, "Failed to connect to database: Error: %s\n",
 	              mysql_error(mysql));
 		return exit_status();
 	}
+	diag("Connected successfully.");
 
-	diag("Running 'SET sql_log_bin=0' for a not privileged user: sbtest1");
-	MYSQL_QUERY(mysql, "SET sql_log_bin=0");
-
+	diag("Attempting 'SET sql_log_bin=0' as 'sbtest1' (should fail or cause issues)");
+	int set_res = mysql_query(mysql, "SET sql_log_bin=0");
+	if (set_res == 0) {
+		diag("'SET sql_log_bin=0' unexpectedly SUCCEEDED.");
+	} else {
+		diag("'SET sql_log_bin=0' FAILED as expected. Error: %s", mysql_error(mysql));
+	}
 
+	diag("Executing 'SELECT 1' to verify connection state...");
 	int query_res = mysql_query(mysql, "SELECT 1");
+	if (query_res == 0) {
+		diag("'SELECT 1' unexpectedly SUCCEEDED.");
+		MYSQL_RES *res = mysql_store_result(mysql);
+		if (res) mysql_free_result(res);
+	} else {
+		diag("'SELECT 1' FAILED as expected. Error: %s", mysql_error(mysql));
+	}
+
 	ok(query_res!=0, "Query \"SELECT 1\" should fail. Error: %s", (query_res == 0 ? "None" : mysql_error(mysql)));