init

2026-08-31 17:09:21 +02:00
parent 57e5114b60
commit 45ca18b74e
38 changed files with 6169 additions and 1 deletions
@@ -0,0 +1,215 @@
+package composeedit
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+type ParseResult struct {
+	Value any `json:"value"`
+}
+
+type Patch struct {
+	Path   []string `json:"path"`
+	Value  any      `json:"value"`
+	Delete bool     `json:"delete"`
+}
+
+func Parse(src string) (ParseResult, error) {
+	var doc yaml.Node
+	if err := yaml.Unmarshal([]byte(src), &doc); err != nil {
+		return ParseResult{}, fmt.Errorf("yaml: %w", err)
+	}
+	if len(doc.Content) == 0 {
+		return ParseResult{Value: map[string]any{}}, nil
+	}
+	var v any
+	if err := doc.Content[0].Decode(&v); err != nil {
+		return ParseResult{}, err
+	}
+	v = normalize(v)
+	return ParseResult{Value: v}, nil
+}
+
+func Apply(src string, p Patch) (string, error) {
+	if len(p.Path) == 0 {
+		return "", errors.New("path is required")
+	}
+	var doc yaml.Node
+	if err := yaml.Unmarshal([]byte(src), &doc); err != nil {
+		return "", fmt.Errorf("yaml: %w", err)
+	}
+	if len(doc.Content) == 0 {
+		return "", errors.New("empty yaml document")
+	}
+	root := doc.Content[0]
+	parent, last, err := walkParent(root, p.Path, !p.Delete)
+	if err != nil {
+		return "", err
+	}
+	if p.Delete {
+		if err := deleteChild(parent, last); err != nil {
+			return "", err
+		}
+	} else {
+		n, err := valueNode(p.Value)
+		if err != nil {
+			return "", err
+		}
+		if err := setChild(parent, last, n); err != nil {
+			return "", err
+		}
+	}
+	var b bytes.Buffer
+	enc := yaml.NewEncoder(&b)
+	enc.SetIndent(2)
+	if err := enc.Encode(&doc); err != nil {
+		return "", err
+	}
+	_ = enc.Close()
+	return strings.TrimSuffix(b.String(), "\n") + "\n", nil
+}
+
+func normalize(v any) any {
+	switch x := v.(type) {
+	case map[string]any:
+		out := make(map[string]any, len(x))
+		for k, v := range x {
+			out[k] = normalize(v)
+		}
+		return out
+	case map[any]any:
+		out := map[string]any{}
+		for k, v := range x {
+			out[fmt.Sprint(k)] = normalize(v)
+		}
+		return out
+	case []any:
+		out := make([]any, len(x))
+		for i, v := range x {
+			out[i] = normalize(v)
+		}
+		return out
+	default:
+		return x
+	}
+}
+
+func walkParent(root *yaml.Node, path []string, create bool) (*yaml.Node, string, error) {
+	cur := root
+	for _, seg := range path[:len(path)-1] {
+		if cur.Kind == yaml.DocumentNode && len(cur.Content) > 0 {
+			cur = cur.Content[0]
+		}
+		switch cur.Kind {
+		case yaml.MappingNode:
+			n := mapGet(cur, seg)
+			if n == nil {
+				if !create {
+					return nil, "", fmt.Errorf("path %q not found", seg)
+				}
+				n = &yaml.Node{Kind: yaml.MappingNode, Tag: "!!map"}
+				mapSet(cur, seg, n)
+			}
+			cur = n
+		case yaml.SequenceNode:
+			i, err := strconv.Atoi(seg)
+			if err != nil || i < 0 || i >= len(cur.Content) {
+				return nil, "", fmt.Errorf("invalid array index %q", seg)
+			}
+			cur = cur.Content[i]
+		default:
+			return nil, "", fmt.Errorf("cannot descend through scalar at %q", seg)
+		}
+	}
+	return cur, path[len(path)-1], nil
+}
+func mapGet(m *yaml.Node, key string) *yaml.Node {
+	for i := 0; i+1 < len(m.Content); i += 2 {
+		if m.Content[i].Value == key {
+			return m.Content[i+1]
+		}
+	}
+	return nil
+}
+func mapSet(m *yaml.Node, key string, v *yaml.Node) {
+	for i := 0; i+1 < len(m.Content); i += 2 {
+		if m.Content[i].Value == key {
+			old := m.Content[i+1]
+			v.HeadComment = old.HeadComment
+			v.LineComment = old.LineComment
+			v.FootComment = old.FootComment
+			m.Content[i+1] = v
+			return
+		}
+	}
+	m.Content = append(m.Content, &yaml.Node{Kind: yaml.ScalarNode, Tag: "!!str", Value: key}, v)
+}
+func setChild(p *yaml.Node, key string, v *yaml.Node) error {
+	switch p.Kind {
+	case yaml.MappingNode:
+		mapSet(p, key, v)
+		return nil
+	case yaml.SequenceNode:
+		if key == "-" {
+			p.Content = append(p.Content, v)
+			return nil
+		}
+		i, err := strconv.Atoi(key)
+		if err != nil || i < 0 || i > len(p.Content) {
+			return fmt.Errorf("invalid array index %q", key)
+		}
+		if i == len(p.Content) {
+			p.Content = append(p.Content, v)
+		} else {
+			old := p.Content[i]
+			v.HeadComment, v.LineComment, v.FootComment = old.HeadComment, old.LineComment, old.FootComment
+			p.Content[i] = v
+		}
+		return nil
+	default:
+		return errors.New("parent is not a map or array")
+	}
+}
+func deleteChild(p *yaml.Node, key string) error {
+	switch p.Kind {
+	case yaml.MappingNode:
+		for i := 0; i+1 < len(p.Content); i += 2 {
+			if p.Content[i].Value == key {
+				p.Content = append(p.Content[:i], p.Content[i+2:]...)
+				return nil
+			}
+		}
+		return nil
+	case yaml.SequenceNode:
+		i, err := strconv.Atoi(key)
+		if err != nil || i < 0 || i >= len(p.Content) {
+			return fmt.Errorf("invalid array index %q", key)
+		}
+		p.Content = append(p.Content[:i], p.Content[i+1:]...)
+		return nil
+	default:
+		return errors.New("parent is not a map or array")
+	}
+}
+func valueNode(v any) (*yaml.Node, error) {
+	raw, err := json.Marshal(v)
+	if err != nil {
+		return nil, err
+	}
+	var x any
+	if err := json.Unmarshal(raw, &x); err != nil {
+		return nil, err
+	}
+	var n yaml.Node
+	if err := n.Encode(x); err != nil {
+		return nil, err
+	}
+	return &n, nil
+}
@@ -0,0 +1,31 @@
+package composeedit
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestPatchPreservesUnknownAndComments(t *testing.T) {
+	src := "# top\nservices:\n  app:\n    image: nginx:old # keep\n    x-future:\n      magic: true\n    deploy:\n      replicas: 2\n"
+	out, e := Apply(src, Patch{Path: []string{"services", "app", "image"}, Value: "nginx:new"})
+	if e != nil {
+		t.Fatal(e)
+	}
+	if !strings.Contains(out, "x-future:") || !strings.Contains(out, "magic: true") || !strings.Contains(out, "replicas: 2") || !strings.Contains(out, "# top") {
+		t.Fatalf("preservation failed:\n%s", out)
+	}
+	r, e := Parse(out)
+	if e != nil || r.Value == nil {
+		t.Fatalf("parse %v", e)
+	}
+}
+func TestArrayPatch(t *testing.T) {
+	src := "services:\n  app:\n    ports:\n      - 8080:80\n"
+	out, e := Apply(src, Patch{Path: []string{"services", "app", "ports", "0"}, Value: "9090:80"})
+	if e != nil {
+		t.Fatal(e)
+	}
+	if !strings.Contains(out, "9090:80") {
+		t.Fatal(out)
+	}
+}