Bug report: can not parse DynamoDBAttributeValue on aws lambda

[imtbkcat]

Hi, I wrote a lambda function to process DynamoDB Stream data, when I try to parser value about "NewImage" and "OldImage" field in DynamoDB Stream events according to

https://github.com/aws/aws-lambda-go/blob/master/events/README_DynamoDB.md

In this document, it says we could use value.Integer() to read a integer value, this works well in local test.
But we I deploy lambda into aws, the error occur:

accessor called for incompatible type, requested type 5 but actual type was 0: IncompatibleDynamoDBTypeError

I try to print the DynamoDBAttributeValue, it looks normal: { "N":"123456"}

Is there any method to fix this issue?

[shaneHowearth]

Hi imtbkcat

We've just come across this issue at work.

We discovered that in our case that if you dump the whole record (from the stream) to a log that the NEW_IMAGE and OLD_IMAGE were nil (for INSERT operations). In our case this was because the creation of the Dynamo Database stream was set to OLD_IMAGE, not NEW_IMAGE or OLD_AND_NEW_IMAGES

[jamessouth]

For type conversion please see the solution in this discussion. The numbers for the types come from here; the list is 0-indexed so 5 is Number, 7 is Null, etc.