working commit

vendor/k8s.io/apimachinery/pkg/util/diff/diff.go

@@ -0,0 +1,62 @@
+//go:build !usegocmp
+// +build !usegocmp
+
+/*
+Copyright 2025 The Kubernetes Authors.
+
+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 diff
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/pmezard/go-difflib/difflib"
+
+	"k8s.io/apimachinery/pkg/util/dump"
+)
+
+// Diff returns a string representation of the difference between two objects.
+// When built without the usegocmp tag, it uses go-difflib/difflib to generate a
+// unified diff of the objects. It attempts to use JSON serialization first,
+// falling back to an object dump via the dump package if JSON marshaling fails.
+func Diff(a, b any) string {
+
+	aStr, aErr := toPrettyJSON(a)
+	bStr, bErr := toPrettyJSON(b)
+	if aErr != nil || bErr != nil {
+		aStr = dump.Pretty(a)
+		bStr = dump.Pretty(b)
+	}
+
+	diff := difflib.UnifiedDiff{
+		A:       difflib.SplitLines(aStr),
+		B:       difflib.SplitLines(bStr),
+		Context: 3,
+	}
+
+	diffstr, err := difflib.GetUnifiedDiffString(diff)
+	if err != nil {
+		return fmt.Sprintf("error generating diff: %v", err)
+	}
+
+	return diffstr
+}
+
+// toPrettyJSON converts an object to a pretty-printed JSON string.
+func toPrettyJSON(data any) (string, error) {
+	jsonData, err := json.MarshalIndent(data, "", " ")
+	return string(jsonData), err
+}