How to do it...

1. Create the project from the following template:

$ sls create --template-url https://github.com/danteinc/js-cloud-native-cookbook/tree/master/ch1/create-stream-processor --path cncb-create-stream-processor

2. Navigate to the cncb-create-stream-processor directory with cd cncb-create-stream-processor.
3. Review the file named serverless.yml with the following content:

service: cncb-create-stream-processor

provider:
  name: aws
  runtime: nodejs8.10
    
functions:
  listener:
    handler: handler.listener
    events:
      - stream:
          type: kinesis
          arn: ${cf:cncb-event-stream-${opt:stage}.streamArn}
          batchSize: 100
          startingPosition: TRIM_HORIZON

4. Review the file named handler.js with the following content:

const _ = require('highland');

module.exports.listener = (event, context, cb) => {
  _(event.Records)
    .map(recordToEvent)
    .tap(printEvent)
    .filter(forThingCreated)
    .collect()
    .tap(printCount)
    .toCallback(cb);
};

const recordToEvent = r => JSON.parse(Buffer.from(r.kinesis.data, 'base64'));
const forThingCreated = e => e.type === 'thing-created';

const printEvent = e => console.log('event: %j', e);
const printCount = events => console.log('count: %d', events.length);

5. Install the dependencies with npm install.
6. Run the tests with npm test -- -s $MY_STAGE.
   
7. Review the contents generated in the .serverless directory.
8. Deploy the stack: 

$ npm run dp:lcl -- -s $MY_STAGE

> cncb-create-stream-processor@1.0.0 dp:lcl <path-to-your-workspace>/cncb-create-stream-processor
> sls deploy -r us-east-1 "-s" "john"

Serverless: Packaging service...
...
Serverless: Stack update finished...
Service Information
service: cncb-create-stream-processor
stage: john
region: us-east-1
stack: cncb-create-stream-processor-john
...
functions:
  listener: cncb-create-stream-processor-john-listener

9. Review the stack and function in the AWS Console.
10. Publish an event from a separate Terminal with the following commands:

$ cd <path-to-your-workspace>/cncb-event-stream
$ sls invoke -r us-east-1 -f publish -s $MY_STAGE -d '{"type":"thing-created"}'
{
    "ShardId": "shardId-000000000000",
    "SequenceNumber": "49582906351415672136958521360120605392824155736450793474"
}

11. Take a look at the logs from the original Terminal:

$ sls logs -f listener -r us-east-1 -s $MY_STAGE
START ...
2018-03-25 00:16:32 ... event:
{
  "type":"thing-created",
  "id":"81fd8920-2fdb-11e8-b749-0d2c43ec73d0",
  "partitionKey":"6f4f9a38-61f7-41c9-a3ad-b8c16e42db7c",
  "timestamp":1521948046003,
  "tags":{
    "region":"us-east-1"
  }
}
2018-03-25 00:16:32 ... event:
{
  "type":"thing-created",
  "id":"c6f60550-2fdd-11e8-b749-0d2c43ec73d0",
  ...
}
2018-03-25 00:16:32 ... count: 2
END ...
REPORT ... Duration: 7.73 ms    Billed Duration: 100 ms ... Max Memory Used: 22 MB    

START ...
2018-03-25 00:22:22 ... event:
{
  "type":"thing-created",
  "id":"1c2b5150-2fe4-11e8-b749-0d2c43ec73d0",
  ...
}
2018-03-25 00:22:22 ... count: 1
END ...
REPORT ... Duration: 1.34 ms    Billed Duration: 100 ms ... Max Memory Used: 22 MB    
 

12. Remove the stack once you are finished with npm run rm:lcl -- -s $MY_STAGE.