Decode native diff paths without revalidation

integrations/ckconfig/diff_report.go

@@ -8,39 +8,17 @@ import (
 	configkit "go.maximumdirect.net/configkit"
 )
 
-func decodeJSONPointer(pointer string) ([]string, error) {
+func decodeJSONPointer(path configkit.Path) []string {
+	pointer := path.String()
 	if pointer == "" {
-		return nil, nil
+		return nil
 	}
-	if pointer[0] != '/' {
-		return nil, fmt.Errorf("decode JSON pointer %q: path must start with /", pointer)
-	}
-
 	parts := strings.Split(pointer[1:], "/")
+	decoder := strings.NewReplacer("~1", "/", "~0", "~")
 	for index, part := range parts {
-		var decoded strings.Builder
-		decoded.Grow(len(part))
-		for offset := 0; offset < len(part); offset++ {
-			if part[offset] != '~' {
-				decoded.WriteByte(part[offset])
-				continue
-			}
-			if offset+1 >= len(part) {
-				return nil, fmt.Errorf("decode JSON pointer %q: incomplete escape in token %d", pointer, index)
-			}
-			offset++
-			switch part[offset] {
-			case '0':
-				decoded.WriteByte('~')
-			case '1':
-				decoded.WriteByte('/')
-			default:
-				return nil, fmt.Errorf("decode JSON pointer %q: invalid escape in token %d", pointer, index)
-			}
-		}
-		parts[index] = decoded.String()
+		parts[index] = decoder.Replace(part)
 	}
-	return parts, nil
+	return parts
 }
 
 func placeReportValue(root any, path []string, value any) (any, error) {
@@ -135,10 +113,7 @@ func renderDiffReport(differences []configkit.Difference) (any, error) {
 		if !difference.Right.Present {
 			continue
 		}
-		tokens, err := decodeJSONPointer(path)
-		if err != nil {
-			return nil, fmt.Errorf("difference at %q: %w", path, err)
-		}
+		tokens := decodeJSONPointer(difference.Path)
 		value, err := commandkit.DecodeYAMLReport(strings.NewReader(difference.Right.YAML))
 		if err != nil {
 			return nil, fmt.Errorf("difference at %q: %w", path, err)

integrations/ckconfig/diff_report_test.go

@@ -3,6 +3,8 @@ package ckconfig
 import (
 	"reflect"
 	"testing"
+
+	configkit "go.maximumdirect.net/configkit"
 )
 
 func TestDecodeJSONPointerPreservesSemanticTokens(t *testing.T) {
@@ -16,21 +18,18 @@ func TestDecodeJSONPointerPreservesSemanticTokens(t *testing.T) {
 		{pointer: "/0/../a.b/50%", want: []string{"0", "..", "a.b", "50%"}},
 		{pointer: "/a~1b/c~0d", want: []string{"a/b", "c~d"}},
 		{pointer: "/~01", want: []string{"~1"}},
+		{pointer: "/café", want: []string{"café"}},
 	}
 	for _, test := range tests {
-		got, err := decodeJSONPointer(test.pointer)
+		path, err := configkit.ParsePath(test.pointer)
 		if err != nil {
-			t.Fatalf("decode %q: %v", test.pointer, err)
+			t.Fatal(err)
 		}
+		got := decodeJSONPointer(path)
 		if !reflect.DeepEqual(got, test.want) {
 			t.Errorf("decode %q = %#v, want %#v", test.pointer, got, test.want)
 		}
 	}
-	for _, pointer := range []string{"missing-leading-slash", "/bad~", "/bad~2escape"} {
-		if _, err := decodeJSONPointer(pointer); err == nil {
-			t.Errorf("decode %q unexpectedly succeeded", pointer)
-		}
-	}
 }
 
 func TestPlaceReportValue(t *testing.T) {