YQL-19747: Fix case sensivity

Bug was that titlecase columns are not completed
on lowercase prefix, e.g. `SELECT a# FROM x`,
where `x = {Age}`.
commit_hash:e48f73176e94bcf16671af56d232450e368c9909

Author: vityaman

yql/essentials/sql/v1/complete/name/object/simple/schema.cpp

@@ -1,5 +1,7 @@
 #include "schema.h"
 
+#include <library/cpp/case_insensitive_string/case_insensitive_string.h>
+
 #include <util/charset/utf8.h>
 
 namespace NSQLComplete {
@@ -11,8 +13,8 @@ namespace NSQLComplete {
             static auto FilterEntriesByName(TString name) {
                 return [name = std::move(name)](auto f) {
                     TVector<TFolderEntry> entries = f.ExtractValue();
-                    EraseIf(entries, [prefix = ToLowerUTF8(name)](const TFolderEntry& entry) {
-                        return !entry.Name.StartsWith(prefix);
+                    EraseIf(entries, [prefix = TCaseInsensitiveStringBuf(name)](const TFolderEntry& entry) {
+                        return !TCaseInsensitiveStringBuf(entry.Name).StartsWith(prefix);
                     });
                     return entries;
                 };
@@ -49,8 +51,8 @@ namespace NSQLComplete {
             static auto FilterColumnsByName(TString name) {
                 return [name = std::move(name)](auto f) {
                     return f.ExtractValue().Transform([&](auto&& table) {
-                        EraseIf(table.Columns, [prefix = ToLowerUTF8(name)](const TString& name) {
-                            return !name.StartsWith(prefix);
+                        EraseIf(table.Columns, [prefix = TCaseInsensitiveStringBuf(name)](const TString& name) {
+                            return !TCaseInsensitiveStringBuf(name).StartsWith(prefix);
                         });
                         return table;
                     });

yql/essentials/sql/v1/complete/name/object/simple/ya.make

@@ -6,6 +6,7 @@ SRCS(
 
 PEERDIR(
     yql/essentials/sql/v1/complete/name/object
+    library/cpp/case_insensitive_string
 )
 
 END()

yql/essentials/sql/v1/complete/name/service/cluster/name_service.cpp

@@ -1,5 +1,7 @@
 #include "name_service.h"
 
+#include <library/cpp/case_insensitive_string/case_insensitive_string.h>
+
 #include <util/charset/utf8.h>
 
 namespace NSQLComplete {
@@ -11,8 +13,8 @@ namespace NSQLComplete {
             static auto FilterByName(TString name) {
                 return [name = std::move(name)](auto f) {
                     TClusterList clusters = f.ExtractValue();
-                    EraseIf(clusters, [prefix = ToLowerUTF8(name)](const TString& instance) {
-                        return !instance.StartsWith(prefix);
+                    EraseIf(clusters, [prefix = TCaseInsensitiveStringBuf(name)](const TString& instance) {
+                        return !TCaseInsensitiveStringBuf(instance).StartsWith(prefix);
                     });
                     return clusters;
                 };

yql/essentials/sql/v1/complete/name/service/cluster/ya.make

@@ -7,6 +7,7 @@ SRCS(
 PEERDIR(
     yql/essentials/sql/v1/complete/name/cluster
     yql/essentials/sql/v1/complete/name/service
+    library/cpp/case_insensitive_string
 )
 
 END()

yql/essentials/sql/v1/complete/sql_complete_ut.cpp

@@ -109,8 +109,8 @@ Y_UNIT_TEST_SUITE(SqlCompleteTests) {
             }},
             "example": { "type": "Folder", "entries": {
                 "people": { "type": "Table", "columns": {
-                    "name": {},
-                    "age": {}
+                    "Name": {},
+                    "Age": {}
                 }},
                 "yql": { "type": "Folder", "entries": {
                     "tutorial": { "type": "Table", "columns": {} }
@@ -1075,29 +1075,29 @@ Y_UNIT_TEST_SUITE(SqlCompleteTests) {
         auto engine = MakeSqlCompletionEngineUT();
         {
             TVector<TCandidate> expected = {
-                {ColumnName, "age"},
-                {ColumnName, "name"},
+                {ColumnName, "Age"},
+                {ColumnName, "Name"},
             };
             UNIT_ASSERT_VALUES_EQUAL(CompleteTop(2, engine, "SELECT # FROM example.`/people`"), expected);
         }
         {
             TVector<TCandidate> expected = {
-                {ColumnName, "age"},
+                {ColumnName, "Age"},
                 {Keyword, "ALL"},
             };
             UNIT_ASSERT_VALUES_EQUAL(CompleteTop(2, engine, "SELECT a# FROM example.`/people`"), expected);
         }
         {
             TVector<TCandidate> expected = {
-                {ColumnName, "age"},
-                {ColumnName, "name"},
+                {ColumnName, "Age"},
+                {ColumnName, "Name"},
             };
             UNIT_ASSERT_VALUES_EQUAL(CompleteTop(2, engine, "USE example; SELECT # FROM `/people`"), expected);
         }
         {
             TVector<TCandidate> expected = {
-                {ColumnName, "x.age"},
-                {ColumnName, "x.name"},
+                {ColumnName, "x.Age"},
+                {ColumnName, "x.Name"},
             };
             UNIT_ASSERT_VALUES_EQUAL(CompleteTop(2, engine, "SELECT # FROM example.`/people` AS x"), expected);
         }
@@ -1107,7 +1107,7 @@ Y_UNIT_TEST_SUITE(SqlCompleteTests) {
         }
         {
             TVector<TCandidate> expected = {
-                {ColumnName, "age"},
+                {ColumnName, "Age"},
             };
             UNIT_ASSERT_VALUES_EQUAL(CompleteTop(2, engine, "SELECT x.a# FROM example.`/people` AS x"), expected);
         }