chore: import upstream snapshot with attribution

server/node/drop_role.go

@@ -0,0 +1,113 @@
+// Copyright 2024 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/server/auth"
+)
+
+// DropRole handles the DROP ROLE statement.
+type DropRole struct {
+	Names    []string
+	IfExists bool
+}
+
+var _ sql.ExecSourceRel = (*DropRole)(nil)
+var _ vitess.Injectable = (*DropRole)(nil)
+
+// Children implements the interface sql.ExecSourceRel.
+func (c *DropRole) Children() []sql.Node {
+	return nil
+}
+
+// IsReadOnly implements the interface sql.ExecSourceRel.
+func (c *DropRole) IsReadOnly() bool {
+	return false
+}
+
+// Resolved implements the interface sql.ExecSourceRel.
+func (c *DropRole) Resolved() bool {
+	return true
+}
+
+// RowIter implements the interface sql.ExecSourceRel.
+func (c *DropRole) RowIter(ctx *sql.Context, r sql.Row) (sql.RowIter, error) {
+	// TODO: disallow dropping the role if it owns anything
+	// First we'll loop over all of the names to check that they all exist
+	var userRole auth.Role
+	var roles []auth.Role
+	var err error
+	auth.LockRead(func() {
+		userRole = auth.GetRole(ctx.Client().User)
+		for _, roleName := range c.Names {
+			role := auth.GetRole(roleName)
+			if role.IsValid() {
+				roles = append(roles, role)
+			} else if !c.IfExists {
+				err = errors.Errorf(`role "%s" does not exist`, roleName)
+				break
+			}
+			if !userRole.IsSuperUser && (role.IsSuperUser || !userRole.CanCreateRoles) {
+				// TODO: grab the actual error message
+				err = errors.Errorf(`role "%s" does not have permission to drop role "%s"`, userRole.Name, role.Name)
+				break
+			}
+		}
+	})
+	if err != nil {
+		return nil, err
+	}
+	// Then we'll loop again, dropping all of the users
+	auth.LockWrite(func() {
+		for _, role := range roles {
+			auth.DropRole(role.Name)
+		}
+		err = auth.PersistChanges()
+	})
+	if err != nil {
+		return nil, err
+	}
+	return sql.RowsToRowIter(), nil
+}
+
+// Schema implements the interface sql.ExecSourceRel.
+func (c *DropRole) Schema(ctx *sql.Context) sql.Schema {
+	return nil
+}
+
+// String implements the interface sql.ExecSourceRel.
+func (c *DropRole) String() string {
+	return "DROP ROLE"
+}
+
+// WithChildren implements the interface sql.ExecSourceRel.
+func (c *DropRole) WithChildren(ctx *sql.Context, children ...sql.Node) (sql.Node, error) {
+	return plan.NillaryWithChildren(c, children...)
+}
+
+// WithResolvedChildren implements the interface vitess.Injectable.
+func (c *DropRole) WithResolvedChildren(ctx context.Context, children []any) (any, error) {
+	if len(children) != 0 {
+		return nil, ErrVitessChildCount.New(0, len(children))
+	}
+	return c, nil
+}