chore: import upstream snapshot with attribution

server/node/drop_cast.go

@@ -0,0 +1,105 @@
+// Copyright 2026 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"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/plan"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+
+	"github.com/dolthub/doltgresql/core"
+	"github.com/dolthub/doltgresql/core/id"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// DropCast implements DROP CAST.
+type DropCast struct {
+	Source   *pgtypes.DoltgresType
+	Target   *pgtypes.DoltgresType
+	IfExists bool
+}
+
+var _ sql.ExecSourceRel = (*DropCast)(nil)
+var _ vitess.Injectable = (*DropCast)(nil)
+
+// NewDropCast returns a new *DropCast.
+func NewDropCast(source *pgtypes.DoltgresType, target *pgtypes.DoltgresType, ifExists bool) *DropCast {
+	return &DropCast{
+		Source:   source,
+		Target:   target,
+		IfExists: ifExists,
+	}
+}
+
+// Children implements the interface sql.ExecSourceRel.
+func (c *DropCast) Children() []sql.Node {
+	return nil
+}
+
+// IsReadOnly implements the interface sql.ExecSourceRel.
+func (c *DropCast) IsReadOnly() bool {
+	return false
+}
+
+// Resolved implements the interface sql.ExecSourceRel.
+func (c *DropCast) Resolved() bool {
+	return true
+}
+
+// RowIter implements the interface sql.ExecSourceRel.
+func (c *DropCast) RowIter(ctx *sql.Context, r sql.Row) (sql.RowIter, error) {
+	castCollection, err := core.GetCastsCollectionFromContext(ctx, "")
+	if err != nil {
+		return nil, err
+	}
+	castID := id.NewCast(c.Source.ID, c.Target.ID)
+	if !castCollection.HasCast(ctx, castID) {
+		if c.IfExists {
+			// TODO: send notice "cast from type SOURCE_NAME to type TARGET_NAME does not exist, skipping"
+			return sql.RowsToRowIter(), nil
+		}
+		return nil, errors.Errorf("cast from type %s to type %s does not exist", c.Source.Name(), c.Target.Name())
+	}
+	if err = castCollection.DropCast(ctx, castID); err != nil {
+		return nil, err
+	}
+	return sql.RowsToRowIter(), nil
+}
+
+// Schema implements the interface sql.ExecSourceRel.
+func (c *DropCast) Schema(ctx *sql.Context) sql.Schema {
+	return nil
+}
+
+// String implements the interface sql.ExecSourceRel.
+func (c *DropCast) String() string {
+	return "DROP CAST"
+}
+
+// WithChildren implements the interface sql.ExecSourceRel.
+func (c *DropCast) WithChildren(ctx *sql.Context, children ...sql.Node) (sql.Node, error) {
+	return plan.NillaryWithChildren(c, children...)
+}
+
+// WithResolvedChildren implements the interface vitess.Injectable.
+func (c *DropCast) WithResolvedChildren(ctx context.Context, children []any) (any, error) {
+	if len(children) != 0 {
+		return nil, ErrVitessChildCount.New(0, len(children))
+	}
+	return c, nil
+}