chore: import upstream snapshot with attribution

server/node/no_op.go

@@ -0,0 +1,87 @@
+// Copyright 2025 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package node
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"github.com/dolthub/dolt/go/libraries/doltcore/sqle/dsess"
+	"github.com/dolthub/go-mysql-server/sql"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+	"github.com/jackc/pgx/v5/pgproto3"
+)
+
+var _ vitess.Injectable = (*NoOp)(nil)
+var _ sql.ExecSourceRel = (*NoOp)(nil)
+
+// NoOp is a node that does nothing and issues zero or more warnings when run.
+// Used when a statement should parse but isn't expected to do anything, for compatibility with Postgres dumps / tools.
+type NoOp struct {
+	Warnings []string
+}
+
+func (n NoOp) Resolved() bool {
+	return true
+}
+
+func (n NoOp) String() string {
+	return fmt.Sprintf("%v", n.Warnings)
+}
+
+func (n NoOp) Schema(ctx *sql.Context) sql.Schema {
+	return nil
+}
+
+func (n NoOp) Children() []sql.Node {
+	return nil
+}
+
+func (n NoOp) WithChildren(ctx *sql.Context, children ...sql.Node) (sql.Node, error) {
+	return n, nil
+}
+
+func (n NoOp) IsReadOnly() bool {
+	return true
+}
+
+func (n NoOp) WithResolvedChildren(ctx context.Context, children []any) (any, error) {
+	return n, nil
+}
+
+type noOpRowIter struct {
+	warnings []string
+}
+
+func (n noOpRowIter) Next(ctx *sql.Context) (sql.Row, error) {
+	return nil, io.EOF
+}
+
+func (n noOpRowIter) Close(ctx *sql.Context) error {
+	for _, warning := range n.warnings {
+		noticeResponse := &pgproto3.NoticeResponse{
+			Severity: "WARNING",
+			Message:  warning,
+		}
+		sess := dsess.DSessFromSess(ctx.Session)
+		sess.Notice(noticeResponse)
+	}
+	return nil
+}
+
+func (n NoOp) RowIter(ctx *sql.Context, r sql.Row) (sql.RowIter, error) {
+	return noOpRowIter{warnings: n.Warnings}, nil
+}