kinesis-events

AWS Kinesis event parser and handler for Lambda consumers. Ability to parse kinesis events with error handling and JSON support. Supports Node 8.10+ on AWS Lambda.

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Install

npm i --save kinesis-events

Usage

const kinesisEvents = require('kinesis-events');
 
// Lambda function handler
exports.handler = async event => {
    // Parse the records
    const result = kinesisEvents.parse(event);
    
    // Check for errors (optional)
    if(result.hasErrors) {
        console.error('There are errors while parsing, ending process...');
        process.exit(1);
    }
    
    result.records.forEach(record => {
        //... iterate through the parsed records
    });
};

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API Documentation

kinesis-events

kinesisEvents : KinesisEvents ⏏

Instance of the KinesisEvents class which is exported when calling require('kinesis-events'). For more advanced usage, you may create a new instance of KinesisEvents (see example below).

Kind: Exported KinesisEvents Instance
Example

const kinesisEvents = require('kinesis-events');
 
// Advanced usage
const { KinesisEvents } = require('kinesis-events');
const kinesisEvents = new KinesisEvents({
    // options...
});

ParseError ⇐ Error

Custom error that is generated when there is a parsing error.

Kind: global class
Extends: Error

parseError.payload : String

The original data that caused the error.

Kind: instance property of ParseError

KinesisEvents

Kind: global class

• KinesisEvents
  • new KinesisEvents([options])
  • kinesisEvents.options : Object
  • kinesisEvents.ParseError : ParseError
  • kinesisEvents.parse(records, [json]) ⇒ RecordSet

new KinesisEvents([options])

Constructor for KinesisEvents.

Param	Type	Default	Description
[options]	Object	{}	Options object to control certain features of KinesisEvents.
[options.transform(record, index)]	function		Optional transform function to call for each record. See Transform Function.

kinesisEvents.options : Object

Options object for KinesisEvents. Allows overridding options after instantiation.

Kind: instance property of KinesisEvents
Example

kinesisEvents.options.transform = function(record, index) {
    // transform record...
    return record;
};

kinesisEvents.ParseError : ParseError

Access to the ParseError class.

Kind: instance property of KinesisEvents
Read only: true

kinesisEvents.parse(records, [json]) ⇒ RecordSet

Parses records from the incoming Kinesis event.

Kind: instance method of KinesisEvents
Returns: RecordSet - New instance of RecordSet with the parsed records.

Param	Type	Default	Description
records	Array		Event data (records) to parse.
[json]	Boolean	true	Enable/disable JSON parsing for each event.

Example

const result = kinesisEvents.parse(event.Records);
 
result.records.forEach(record => {
    // do something with each record...
});

RecordSet

A set of parsed records with additional functionality.

Kind: global class

• RecordSet
  • recordSet.records : Array
  • recordSet.failed : Array.<ParseError>
  • recordSet.length : Number
  • recordSet.hasErrors : Boolean

recordSet.records : Array

The records within this record set.

Kind: instance property of RecordSet

recordSet.failed : Array.<ParseError>

List of failed records (ParseError).

Kind: instance property of RecordSet

recordSet.length : Number

The total number of parsed records in the record set.

Kind: instance property of RecordSet
Read only: true

recordSet.hasErrors : Boolean

Boolean flag if this record set has failed records.

Kind: instance property of RecordSet
Read only: true

Transform Function

New in v3.0.0, there is now an option to pass in a transform function that will allow you to transform the record before it is added to the RecordSet. This allows custom functionality or business logic to be implemented at a higher level.

The transform function takes 2 arguments, record and index. The function must return the transformed record in order for it to be added to the RecordSet. If the record is not returned from the function, it will be ignored.

const { KinesisEvents } = require('kinesis-events');
const kinesisEvents = new KinesisEvents({
    transform: (record, index) => {
        if(record.firstName && record.lastName) {
            // example, remove record if data is missing
            return null;
        }
        
        record.someCustomProperty = 'some custom value';
        return record;
    }
});

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Tests

Tests are written and provided as part of the module. It requires mocha to be installed which is included as a devDependency. You may run the tests by calling:

$ npm run test

License

MIT License. See License in the repository.