[YQL-2610] Add setting to prohibit cast from Yson to string. Disable CAST from Yson to String in tests

ref:039e04a61aaeb02dc58968abe3755433b7158fcc

6 files changed, 45 insertions, 7 deletions

diff --git a/ydb/library/yql/core/type_ann/type_ann_core.cpp b/ydb/library/yql/core/type_ann/type_ann_core.cpp
index 3f84541a4e3..a2e20dcc89c 100644
--- a/ydb/library/yql/core/type_ann/type_ann_core.cpp
+++ b/ydb/library/yql/core/type_ann/type_ann_core.cpp
@@ -3905,7 +3905,7 @@ namespace NTypeAnnImpl {
     }
 
     template <bool Strong>
-    IGraphTransformer::TStatus CastWrapper(const TExprNode::TPtr& input, TExprNode::TPtr& output, TContext& ctx) {
+    IGraphTransformer::TStatus CastWrapper(const TExprNode::TPtr& input, TExprNode::TPtr& output, TExtContext& ctx) {
         if (!EnsureMinArgsCount(*input, 2, ctx.Expr)) {
             return IGraphTransformer::TStatus::Error;
         }
@@ -4000,10 +4000,17 @@ namespace NTypeAnnImpl {
                 }
 
                 if (sourceDataType->GetSlot() == EDataSlot::Yson && targetDataType->GetSlot() == EDataSlot::String) {
-                    auto issue = TIssue(ctx.Expr.GetPosition(input->Head().Pos()), "Consider using ToBytes to get internal representation of Yson type,"
-                        " or Yson::ConvertToString* methods to get string values");
-                    SetIssueCode(EYqlIssueCode::TIssuesIds_EIssueCode_CORE_CAST_YSON_JSON_BYTES, issue);
-                    if (!ctx.Expr.AddWarning(issue)) {
+                    const TString msg = "Consider using ToBytes to get internal representation of Yson type,"
+                                        " or Yson::ConvertToString* methods to get string values";
+                    if (ctx.Types.YsonCastToString) {
+                        auto issue = TIssue(ctx.Expr.GetPosition(input->Head().Pos()), msg);
+                        SetIssueCode(EYqlIssueCode::TIssuesIds_EIssueCode_CORE_CAST_YSON_JSON_BYTES, issue);
+                        if (!ctx.Expr.AddWarning(issue)) {
+                            return IGraphTransformer::TStatus::Error;
+                        }
+                    } else {
+                        ctx.Expr.AddError(TIssue(ctx.Expr.GetPosition(input->Head().Pos()),
+                            TStringBuilder() << "Casting Yson to String is ambiguous. " << msg));
                         return IGraphTransformer::TStatus::Error;
                     }
                 }
@@ -11078,8 +11085,6 @@ template <NKikimr::NUdf::EDataSlot DataSlot>
         Functions["AlterTo"] = &AlterToWrapper;
         Functions["ToIntegral"] = &ToIntegralWrapper;
         Functions["Cast"] = &OldCastWrapper;
-        Functions["SafeCast"] = &CastWrapper<false>;
-        Functions["StrictCast"] = &CastWrapper<true>;
         Functions["BitCast"] = &BitCastWrapper;
         Functions["WidenIntegral"] = &WidenIntegralWrapper;
         Functions["Default"] = &DefaultWrapper;
@@ -11471,6 +11476,8 @@ template <NKikimr::NUdf::EDataSlot DataSlot>
         ExtFunctions["AssumeColumnOrder"] = &AssumeColumnOrderWrapper;
         ExtFunctions["AssumeColumnOrderPartial"] = &AssumeColumnOrderWrapper;
         ExtFunctions["UnionAllPositional"] = &UnionAllPositionalWrapper;
+        ExtFunctions["SafeCast"] = &CastWrapper<false>;
+        ExtFunctions["StrictCast"] = &CastWrapper<true>;
 
         ColumnOrderFunctions["PgSetItem"] = &OrderForPgSetItem;
         ColumnOrderFunctions["AssumeColumnOrder"] = &OrderForAssumeColumnOrder;
diff --git a/ydb/library/yql/core/yql_type_annotation.h b/ydb/library/yql/core/yql_type_annotation.h
index 32d267be440..6333bd75992 100644
--- a/ydb/library/yql/core/yql_type_annotation.h
+++ b/ydb/library/yql/core/yql_type_annotation.h
@@ -220,6 +220,7 @@ struct TTypeAnnotationContext: public TThrRefBase {
     TString DqFallbackPolicy = "";
     bool StrictTableProps = true;
     bool JsonQueryReturnsJsonDocument = false;
+    bool YsonCastToString = true;
     ui32 FolderSubDirsLimit = 1000;
 
     // compatibility with v0 or raw s-expression code
diff --git a/ydb/library/yql/providers/config/yql_config_provider.cpp b/ydb/library/yql/providers/config/yql_config_provider.cpp
index 6952e96cf07..ec5309a8503 100644
--- a/ydb/library/yql/providers/config/yql_config_provider.cpp
+++ b/ydb/library/yql/providers/config/yql_config_provider.cpp
@@ -745,6 +745,14 @@ namespace {
                     return false;
                 }
             }
+            else if (name == "YsonCastToString" || name == "DisableYsonCastToString") {
+                if (args.size() != 0) {
+                    ctx.AddError(TIssue(pos, TStringBuilder() << "Expected no arguments, but got " << args.size()));
+                    return false;
+                }
+
+                Types.YsonCastToString = (name == "YsonCastToString");
+            }
             else {
                 ctx.AddError(TIssue(pos, TStringBuilder() << "Unsupported command: " << name));
                 return false;
diff --git a/ydb/library/yql/sql/v1/context.h b/ydb/library/yql/sql/v1/context.h
index bc446962b08..f4bd15847ee 100644
--- a/ydb/library/yql/sql/v1/context.h
+++ b/ydb/library/yql/sql/v1/context.h
@@ -264,6 +264,7 @@ namespace NSQLTranslationV1 {
         bool FlexibleTypes = false;
         // see YQL-10265
         bool AnsiCurrentRow = false;
+        TMaybe<bool> YsonCastToString;
         THashMap<TString, TMaybe<TString>> Libraries; // alias -> optional file
         THashMap<TString, ui32> PackageVersions;
         NYql::TWarningPolicy WarningPolicy;
diff --git a/ydb/library/yql/sql/v1/query.cpp b/ydb/library/yql/sql/v1/query.cpp
index df41d79a877..d054a383958 100644
--- a/ydb/library/yql/sql/v1/query.cpp
+++ b/ydb/library/yql/sql/v1/query.cpp
@@ -1775,6 +1775,11 @@ public:
                             BuildQuotedAtom(Pos, "Attr"), BuildQuotedAtom(Pos, "Dummy_"), BuildQuotedAtom(Pos, "1"))));
                     }
                 }
+
+                if (ctx.YsonCastToString.Defined()) {
+                    const TString pragmaName = *ctx.YsonCastToString ? "YsonCastToString" : "DisableYsonCastToString";
+                    Add(Y("let", "world", Y(TString(ConfigureName), "world", configSource, BuildQuotedAtom(Pos, pragmaName))));
+                }
             }
         }
 
diff --git a/ydb/library/yql/sql/v1/sql.cpp b/ydb/library/yql/sql/v1/sql.cpp
index 0595f746906..8792f57f7c7 100644
--- a/ydb/library/yql/sql/v1/sql.cpp
+++ b/ydb/library/yql/sql/v1/sql.cpp
@@ -9777,6 +9777,22 @@ TNodePtr TSqlQuery::PragmaStatement(const TRule_pragma_stmt& stmt, bool& success
                     Ctx.IncrementMonCounter("sql_errors", "BadPragmaValue");
                 }
                 return {};
+            } else if (normalizedPragma == "casttostring" || normalizedPragma == "disablecasttostring") {
+                const bool allow = normalizedPragma == "casttostring";
+                if (values.size() == 0U) {
+                    Ctx.YsonCastToString = allow;
+                    success = true;
+                    return {};
+                }
+                bool pragmaYsonCastToString;
+                if (values.size() == 1U && values.front().GetLiteral() && TryFromString(*values.front().GetLiteral(), pragmaYsonCastToString)) {
+                    Ctx.PragmaYsonStrict = allow ? pragmaYsonCastToString : !pragmaYsonCastToString;
+                    success = true;
+                } else {
+                    Error() << "Expected 'true', 'false' or no parameter for: " << pragma;
+                    Ctx.IncrementMonCounter("sql_errors", "BadPragmaValue");
+                }
+                return {};
             } else {
                 Error() << "Unknown pragma: '" << pragma << "'";
                 Ctx.IncrementMonCounter("sql_errors", "BadPragmaValue");