// Copyright 2022 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package protocol
import (
"encoding/json"
"fmt"
)
// DocumentChange is a union of various file edit operations.
//
// Exactly one field of this struct is non-nil; see [DocumentChange.Valid].
//
// See https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#resourceChanges
type DocumentChange struct {
TextDocumentEdit *TextDocumentEdit
CreateFile *CreateFile
RenameFile *RenameFile
DeleteFile *DeleteFile
}
// Valid reports whether the DocumentChange sum-type value is valid,
// that is, exactly one of create, delete, edit, or rename.
func (ch DocumentChange) Valid() bool {
n := 0
if ch.TextDocumentEdit != nil {
n++
}
if ch.CreateFile != nil {
n++
}
if ch.RenameFile != nil {
n++
}
if ch.DeleteFile != nil {
n++
}
return n == 1
}
func (d *DocumentChange) UnmarshalJSON(data []byte) error {
var m map[string]any
if err := json.Unmarshal(data, &m); err != nil {
return err
}
if _, ok := m["textDocument"]; ok {
d.TextDocumentEdit = new(TextDocumentEdit)
return json.Unmarshal(data, d.TextDocumentEdit)
}
// The {Create,Rename,Delete}File types all share a 'kind' field.
kind := m["kind"]
switch kind {
case "create":
d.CreateFile = new(CreateFile)
return json.Unmarshal(data, d.CreateFile)
case "rename":
d.RenameFile = new(RenameFile)
return json.Unmarshal(data, d.RenameFile)
case "delete":
d.DeleteFile = new(DeleteFile)
return json.Unmarshal(data, d.DeleteFile)
}
return fmt.Errorf("DocumentChanges: unexpected kind: %q", kind)
}
func (d *DocumentChange) MarshalJSON() ([]byte, error) {
if d.TextDocumentEdit != nil {
return json.Marshal(d.TextDocumentEdit)
} else if d.CreateFile != nil {
return json.Marshal(d.CreateFile)
} else if d.RenameFile != nil {
return json.Marshal(d.RenameFile)
} else if d.DeleteFile != nil {
return json.Marshal(d.DeleteFile)
}
return nil, fmt.Errorf("empty DocumentChanges union value")
}