pulumi/sdk/go/common/util/yamlutil/edit.go

131 lines
3.2 KiB
Go

// Copyright 2016-2022, Pulumi Corporation.
//
// 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 yamlutil
import (
"errors"
"gopkg.in/yaml.v3"
)
type HasRawValue interface {
RawValue() []byte
}
// Edit does a deep comparison on original and new and returns a YAML document that modifies only
// the nodes changed between original and new.
func Edit(original []byte, new interface{}) ([]byte, error) {
var err error
var oldDoc yaml.Node
err = yaml.Unmarshal(original, &oldDoc)
if err != nil {
return nil, err
}
newBytes, err := yaml.Marshal(new)
if err != nil {
return nil, err
}
var newValue yaml.Node
err = yaml.Unmarshal(newBytes, &newValue)
if err != nil {
return nil, err
}
newValue, err = editNodes(&oldDoc, &newValue)
if err != nil {
return nil, err
}
return YamlEncode(&newValue)
}
func editNodes(original, new *yaml.Node) (yaml.Node, error) {
if original.Kind != new.Kind {
return *new, nil
}
ret := *original
ret.Tag = new.Tag
ret.Value = new.Value
switch original.Kind {
case yaml.DocumentNode, yaml.SequenceNode:
var minLen int
var content []*yaml.Node
if len(new.Content) < len(original.Content) {
minLen = len(new.Content)
} else {
minLen = len(original.Content)
}
for i := 0; i < minLen; i++ {
item, err := editNodes(original.Content[i], new.Content[i])
if err != nil {
return ret, err
}
content = append(content, &item)
}
// Any excess nodes in the new value are copied verbatim
content = append(content, new.Content[minLen:]...)
ret.Content = content
return ret, nil
case yaml.MappingNode:
origKeys := make(map[string]int)
newKeys := make(map[string]int)
var newKeyList []string
var content []*yaml.Node
for i := 0; i < len(original.Content); i += 2 {
origKeys[original.Content[i].Value] = i
}
for i := 0; i < len(new.Content); i += 2 {
value := new.Content[i].Value
newKeys[value] = i
newKeyList = append(newKeyList, value)
}
for _, k := range newKeyList {
newIdx := newKeys[k]
origIdx, has := origKeys[k]
var err error
var key yaml.Node
var value yaml.Node
if has {
key, err = editNodes(original.Content[origIdx], new.Content[newIdx])
if err != nil {
return ret, err
}
value, err = editNodes(original.Content[origIdx+1], new.Content[newIdx+1])
if err != nil {
return ret, err
}
} else {
key = *new.Content[newIdx]
value = *new.Content[newIdx+1]
}
content = append(content, &key)
content = append(content, &value)
}
ret.Content = content
return ret, nil
case yaml.ScalarNode, yaml.AliasNode:
ret.Content = new.Content
return ret, nil
}
return yaml.Node{}, errors.New("unknown node type")
}