Kinesis to Lambda - Parsing Data - json

Question

I'm following this tutorial to push data from my API Gateway to a Kinesis stream :
http://docs.aws.amazon.com/apigateway/latest/developerguide/integrating-api-with-aws-services-kinesis.html#api-gateway-get-and-add-records-to-stream
I have my Body Mapping Template setup as.....
{
"StreamName": "my-stream-name",
"Data": "$util.base64Encode($input.path('$.Data'))",
"PartitionKey": "$input.path('$.PartitionKey')"
}
...and have put the following in the Request Body of an API test...
{
"Data": {
"Foo": "A",
"Bar": "B"
},
"PartitionKey": "some key"
}
I've then created a Lambda Function which has a trigger set up against the same Kinesis Stream. However, I'm struggling to decode/deserialise the records coming in from Kinesis.
exports.handler = (event, context, callback) => {
event.Records.forEach(function(record) {
let payload = JSON.parse(Buffer(record.kinesis.data, 'base64').toString('ascii'))
});
};
It seems that the data is being serialised to Kinesis in a non-JSON format. The value for record.kinesis.data in the forEach loop is
e0Zvbz1BLCBCYXI9Qn0=
...which when push through Buffer(record.kinesis.data, 'base64').toString('ascii')
returns as
{Foo=A, Bar=B}
not
{"Foo":"A", "Bar":"B"}
Main aim is obviously to get payload to in a state where I can say console.log(payload.Foo)
Any hints as to what I should be doing/looking for would be appreciated.

Answer 1

For anyone else out there
I had my Body Mapping Template setup as.....
{
"StreamName": "my-stream-name",
"Data": "$util.base64Encode($input.path('$.Data'))",
"PartitionKey": "$input.path('$.PartitionKey')"
}
Now changed to handle the json....
{
"StreamName": "my-stream-name",
"Data": "$util.base64Encode($input.json('$.Data'))",
"PartitionKey": "$input.path('$.PartitionKey')"
}
where...
($input.json('$.Data'))
is the change :)