event.sns.arn.indexOf is not a function

Serverless Framework
1

Hello,
I have the following

  upload:
    handler: bin/upload
    memorySize: 128
    timeout: 60
    package:
      individually: true
      include:
        - ./bin/upload
    events:
      - sns:
          arn:
            Ref: UploadTopic
          topicName:
            Fn::Join:
              - ""
              - - Fn::GetAtt:
                - "UploadTopic"
                - "TopicName"
    environment:
      UPLOADS_JOB_TABLE_NAME: ${self:provider.region}.${opt:stage}.uploads

then in the Resources section, I have:

resources:
  - ${file(resources/notifications/upload.yml)}

where resources/notifications/upload.yml is:

Resources:
  UploadSQSQueue:
    Type: AWS::SQS::Queue
    Properties:
      MessageRetentionPeriod:
        Ref: MessageRetentionPeriod
      VisibilityTimeout:
        Ref: VisibilityTimeout

  UploadSQSQueuePolicy:
    Type: AWS::SQS::QueuePolicy
    Properties:
      PolicyDocument:
        Version: '2008-10-17'
        Statement:
        - Effect: Allow
          Principal:
            AWS: "*"
          Action:
          - SQS:SendMessage
          Resource: "*"
          Condition:
            ArnEquals:
              aws:SourceArn:
                Ref: UploadTopic
      Queues:
        - Ref: UploadSQSQueue

  UploadTopic:
    Type: AWS::SNS::Topic
    Properties:
      Subscription:
      - Endpoint:
          Fn::GetAtt:
          - UploadSQSQueue
          - Arn
        Protocol: sqs

  UploadTopicPolicy:
    Type: AWS::SNS::TopicPolicy
    Properties:
      PolicyDocument:
        Version: '2012-10-17'
        Statement:
        - Sid: AllowUploadBucketToPushNotificationEffect
          Effect: Allow
          Principal:
            Service: s3.amazonaws.com
          Action: sns:Publish
          Resource: "*"
          # Condition:
          #   ArnLike:
          #     aws:SourceArn:
          #       Fn::Join:
          #       - ''
          #       - - 'arn:aws:s3:*:*:'
          #         # - Ref: UploadBucket
      Topics:
      - Ref: UploadTopic

Outputs:
  UploadSQSQueueURL:
    Description: "URL of newly created SQS Queue"
    Value:
      Ref: "UploadSQSQueue"
  UploadSQSQueueARN:
    Description: "ARN of newly created SQS Queue"
    Value:
      Fn::GetAtt:
        - "UploadSQSQueue"
        - "Arn"
  UploadSQSQueueName:
    Description: "Upload Queue Name"
    Value:
      Fn::GetAtt:
        - "UploadSQSQueue"
        - "QueueName"
  UploadTopicName:
    Description: "Upload SNS Name"
    Value:
      Fn::GetAtt:
        - "UploadTopic"
        - "TopicName"

How do I set the ARN and TopicName to the function?

I get https://github.com/serverless/serverless/issues/3824, I have tried the different options, but get:

  Missing or invalid topicName property for sns event in function "upload" The correct syntax is: sns: topic-name-or-arn OR an object with  arn and topicName OR topicName and displayName. Please check the docs for more info.

Any advice is much appreciated

2

adding:

custom:
  UploadTopicName:
    "Fn::GetAtt": [ "UploadTopic", "TopicName" ]

and referencing it within the function works

  upload:
    handler: bin/upload
    memorySize: 128
    timeout: 60
    package:
      individually: true
      include:
        - ./bin/upload
    iamRoleStatements:
      - Effect: Allow
        Action:
          - dynamodb:GetItem
          - dynamodb:PutItem
        Resource:
          - "Fn::GetAtt": [ uploads, Arn ]
    events:
      - sns:
          arn:
            Ref: UploadTopic
          topicName: UploadTopicName
    environment:
      UPLOADS_JOB_TABLE_NAME: ${self:provider.region}.${opt:stage}.uploads