correct code style

src/Storages/System/StorageSystemWarnings.cpp

@@ -1,10 +1,8 @@
-#include <memory>
-#include <Storages/System/StorageSystemWarnings.h>
 #include <Interpreters/Context.h>
+#include <Storages/System/StorageSystemWarnings.h>
 
 namespace DB
 {
-
 NamesAndTypesList StorageSystemWarnings::getNamesAndTypes()
 {
     return {
@@ -14,9 +12,8 @@ NamesAndTypesList StorageSystemWarnings::getNamesAndTypes()
 
 void StorageSystemWarnings::fillData(MutableColumns & res_columns, ContextPtr context, const SelectQueryInfo &) const
 {
-    for (auto& warning : context->getWarnings()) {
+    for (const auto & warning : context->getWarnings())
         res_columns[0]->insert(warning);
 }
-}
 
 }

src/Storages/System/StorageSystemWarnings.h

@@ -2,11 +2,13 @@
 
 #include <Storages/System/IStorageSystemOneBlock.h>
 
-namespace DB {
+namespace DB
+{
 
 class Context;
 
-class StorageSystemWarnings final : public shared_ptr_helper<StorageSystemWarnings>, public IStorageSystemOneBlock<StorageSystemWarnings> {
+class StorageSystemWarnings final : public shared_ptr_helper<StorageSystemWarnings>,
+                                public IStorageSystemOneBlock<StorageSystemWarnings> {
 public:
     std::string getName() const override { return "SystemWarnings"; }
 

tests/queries/0_stateless/01945_system_warnings.expect

@@ -0,0 +1,34 @@
+#!/usr/bin/expect -f
+
+# This is a test for system.warnings. Testing in interactive mode is necessary,
+# as we want to see certain warnings from client
+
+log_user 0
+set timeout 60
+match_max 100000
+
+# A default timeout action is to do nothing, change it to fail
+expect_after {
+    timeout {
+        exit 1
+    }
+}
+
+set basedir [file dirname $argv0]
+spawn bash -c "source $basedir/../shell_config.sh ; \$CLICKHOUSE_CLIENT_BINARY \$CLICKHOUSE_CLIENT_OPT --disable_suggestion"
+expect ":) "
+
+
+send -- "SELECT value FROM system.build_options WHERE name='BUILD_TYPE'"
+expect {
+    "Debug" {
+        send -- "SELECT message FROM system.warnings WHERE message='Server was built in debug mode. It will work slowly.'"
+        expect "Server was built in debug mode. It will work slowly."
+        expect ":) "
+    }
+    "RelWithDebInfo"
+}
+
+# Finish test
+send -- "\4"
+expect eof