BE-2931 Add Unregistered code to apns and register it as domain.ErrDefectToken (#5)

Add Unregistered code to apns and register it as domain.ErrDefectToken

Author: matveyZholudev

Diff for: api.go

@@ -9,5 +9,8 @@ type rawResp struct {
 // https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/handling_notification_responses_from_apns
 type errorReason string
 
-const reasonExpiredProviderToken errorReason = "ExpiredProviderToken"
-const reasonBadDeviceToken errorReason = "BadDeviceToken"
+const (
+	reasonExpiredProviderToken errorReason = "ExpiredProviderToken"
+	reasonBadDeviceToken       errorReason = "BadDeviceToken"
+	reasonCodeUnregistered     errorReason = "Unregistered"
+)

Diff for: client.go

@@ -139,6 +139,8 @@ func apiErrorReasonToClientError(reason errorReason) error {
 		return ErrExpiredToken
 	case reasonBadDeviceToken:
 		return ErrBadDeviceToken
+	case reasonCodeUnregistered:
+		return ErrUnregistered
 	default:
 		return errors.New(string(reason))
 	}

Diff for: client_test.go

@@ -33,6 +33,14 @@ var _ = Describe("Client", func() {
 			})
 		})
 
+		When("error reason is reasonCodeUnregistered", func() {
+			It("should return ErrUnregistered", func() {
+				errorReason = reasonCodeUnregistered
+				err := apiErrorReasonToClientError(errorReason)
+				Ω(err).Should(Equal(ErrUnregistered))
+			})
+		})
+
 		When("error reason is general error", func() {
 			It("should return Error", func() {
 				errorReason = "anyOtherError"

Diff for: error.go

@@ -4,6 +4,7 @@ const (
 	// Error when token is expired.
 	ErrExpiredToken   Error = "ExpiredProviderToken"
 	ErrBadDeviceToken Error = "BadDeviceToken"
+	ErrUnregistered   Error = "Unregistered"
 )
 
 type Error string