}{
		{
			input: `<Transition>
			<Days>0</Days>
			<StorageClass>S3TIER-1</StorageClass>
		  </Transition>`,
			err: nil,
		},
		{
			input: `<Transition>
			<Days>1</Days>
			<Date>2021-01-01T00:00:00Z</Date>
			<StorageClass>S3TIER-1</StorageClass>
		  </Transition>`,
			err: errTransitionInvalid,
		},
		{
			input: `<Transition>
			<Days>1</Days>
		  </Transition>`,
			err: errXMLNotWellFormed,

)

func TestDelMarkerExpParseAndValidate(t *testing.T) {
	tests := []struct {
		xml string
		err error
	}{
		{
			xml: `<DelMarkerExpiration> <Days> 1 </Days> </DelMarkerExpiration>`,
			err: nil,
		},
		{
			xml: `<DelMarkerExpiration> <Days> -1 </Days> </DelMarkerExpiration>`,
			err: errInvalidDaysDelMarkerExpiration,
		},
	}

	for i, test := range tests {

			expectedParsingErr:    nil,
			expectedValidationErr: errXMLNotWellFormed,
		},
		// Lifecycle with the deprecated Prefix tag
		{

			expectedErr: errInvalidStorageClass,
		},
		{
			// no transition rule
			xml:         []byte(`<LifecycleConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Rule><ID>rule</ID><Prefix /><Status>Enabled</Status><Expiration><Days>1</Days></Expiration></Rule></LifecycleConfiguration>`),

```sh
awscli s3api put-object-lock-configuration --bucket mybucket --object-lock-configuration 'ObjectLockEnabled=\"Enabled\",Rule={DefaultRetention={Mode=\"GOVERNANCE\",Days=1}}'
```

### Set object lock

","monthsRegex$9","symbolMap$f","numberMap$e","੧","੨","੩","੪","੫","੬","੭","੮","੯","੦","monthsNominative","monthsSubjective","monthsParse$a","plural$3","translate$8","relativeTimeWithPlural$2","relativeTimeWithPlural$3","monthsParse$b","months$9","days$1","months$a","monthsShort$7","plural$5","translate$9","processRelativeTime$7","translator$1","translator$2","symbolMap$g","numberMap$f","௧","௨","௩","௪","௫","௬","௭","௮","௯","௦","suffixes$3","12","13","suffixes$4","numbersNouns","translate$a","numbe...

}

// TransitionDays is a type alias to unmarshal Days in Transition
type TransitionDays int

// UnmarshalXML parses number of days from Transition and validates if
// >= 0
func (tDays *TransitionDays) UnmarshalXML(d *xml.Decoder, startElement xml.StartElement) error {
	var days int
	err := d.DecodeElement(&days, &startElement)
	if err != nil {
		return err
	}

	if days < 0 {
		return errTransitionInvalidDays
	}

	errLifecycleInvalidDays         = Errorf("Days must be positive integer when used with Expiration")
	errLifecycleInvalidExpiration   = Errorf("Exactly one of Days (positive integer) or Date (positive ISO 8601 format) should be present inside Expiration.")
	errLifecycleInvalidDeleteMarker = Errorf("Delete marker cannot be specified with Days or Date in a Lifecycle Expiration Policy")

			inputXML: `<Expiration>
                                    <Days>3</Days>
                                    <Date>2019-04-20T00:00:00Z</Date>
                                    </Expiration>`,
			expectedErr: errLifecycleInvalidExpiration,
		},
		{ // Expiration with both ExpiredObjectDeleteMarker and days
			inputXML: `<Expiration>
                                    <Days>3</Days>

	}

	if retention.Days == nil && retention.Years == nil {
		return fmt.Errorf("either Days or Years must be specified")
	}

	if retention.Days != nil && retention.Years != nil {
		return fmt.Errorf("either Days or Years must be specified, not both")
	}

	//nolint:gocritic
	if retention.Days != nil {
		if *retention.Days == 0 {