cluster

obj := &v1.ConfigMap{}
obj.Data = map[string]string{"some-key": "some-value"}

contents := &bytes.Buffer{}
wrapper := DiffWrapper(contents, func(obj *v1.ConfigMap) error {
	obj.Data = map[string]string{"some-key": "new-value"}
	return nil
})

fmt.Println("Error:", wrapper(obj))
firstLine := strings.Split(contents.String(), "\n")[0]
fmt.Println("First line:", firstLine)

Output:
Error: <nil>
First line: ConfigMap Diff (-old +new):

obj := &v1.ConfigMap{}
wrapper := DiffWrapper(os.Stdout, func(_ *v1.ConfigMap) error {
	return errors.New("some-error")
})

fmt.Println(wrapper(obj))

Output:
some-error

obj := &v1.ConfigMap{}

wrapper := DiffWrapper(os.Stdout, func(cm *v1.ConfigMap) error {
	// don't mutate the object
	return nil
})

wrapper(obj)

Output:
No changes