Support retrying failed messages for rate limit on Twilio WhatsApp

Author: norkans7

Diff for: handlers/twiml/handlers.go

@@ -56,6 +56,7 @@ var mediaSupport = map[handlers.MediaType]handlers.MediaTypeSupport{
 
 // error code twilio returns when a contact has sent "stop"
 const errorStopped = 21610
+const errorThrottled = 63018
 
 type handler struct {
 	handlers.BaseHandler
@@ -207,6 +208,9 @@ func (h *handler) receiveStatus(ctx context.Context, channel courier.Channel, w
 			}
 		}
 		clog.Error(twilioError(errorCode))
+		if errorCode == errorThrottled {
+			status = h.Backend().NewStatusUpdateByExternalID(channel, form.MessageSID, courier.MsgStatusErrored, clog)
+		}
 	}
 
 	return handlers.WriteMsgStatusAndResponse(ctx, h, channel, status, w, r)

Diff for: handlers/twiml/handlers_test.go

@@ -66,9 +66,10 @@ var (
 
 	statusStop = "ErrorCode=21610&MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=failed&To=%2B12028831111"
 
-	statusInvalid = "MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=huh"
-	statusValid   = "MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=delivered"
-	statusRead    = "MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=read"
+	statusInvalid   = "MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=huh"
+	statusValid     = "MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=delivered"
+	statusRead      = "MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=read"
+	statusRateLimit = "MessageSid=SMe287d7109a5a925f182f0e07fe5b223b&MessageStatus=failed&ErrorCode=63018"
 
 	tmsStatusExtra  = "SmsStatus=sent&MessageStatus=sent&To=2021&MessagingServiceSid=MGdb23ec0f89ee2632e46e91d8128f5e2b&MessageSid=SM0b6e2697aae04182a9f5b5c7a8994c7f&AccountSid=acctid&From=%2B14133881111&ApiVersion=2010-04-01"
 	tmsReceiveExtra = "ToCountry=US&ToState=&SmsMessageSid=SMbbf29aeb9d380ce2a1c0ae4635ff9dab&NumMedia=0&ToCity=&FromZip=27609&SmsSid=SMbbf29aeb9d380ce2a1c0ae4635ff9dab&FromState=NC&SmsStatus=received&FromCity=RALEIGH&Body=John+Cruz&FromCountry=US&To=384387&ToZip=&NumSegments=1&MessageSid=SMbbf29aeb9d380ce2a1c0ae4635ff9dab&AccountSid=acctid&From=%2B14133881111&ApiVersion=2010-04-01"
@@ -481,6 +482,18 @@ var twaTestCases = []IncomingTestCase{
 		},
 		PrepRequest: addValidSignature,
 	},
+	{
+		Label:                "Status ID Rate limit",
+		URL:                  twaStatusIDURL,
+		Data:                 statusRateLimit,
+		ExpectedRespStatus:   200,
+		ExpectedBodyContains: `"status":"E"`,
+		ExpectedStatuses: []ExpectedStatus{
+			{ExternalID: "SMe287d7109a5a925f182f0e07fe5b223b", Status: courier.MsgStatusErrored},
+		},
+		PrepRequest:    addValidSignature,
+		ExpectedErrors: []*courier.ChannelError{courier.ErrorExternal("63018", "Rate limit exceeded for Channel")},
+	},
 	{
 		Label:                "Status ID Invalid",
 		URL:                  twaStatusInvalidIDURL,