AWS Lambda - JavaScript ES7 Template

Template for testing, mocking events, developing and deploying into AWS Lambda using NodeJS.

Thanks to Babel and this template, you can easily write ES6 & ES7 JavaScript without worrying about the NodeJS version compatibility.

Example

// Native JS import
import ExampleService from './src/Services/ExampleService'

exports.handler = async (event, context) => {
    try {
        // Message passed into Lambda
        const message = JSON.parse(event.Records[0].Sns.Message)
        // Example async execution
        const service = new ExampleService()
        const response = await service.save(message.content)
        console.log(response)

        return
    } catch (error) {
        console.log(error.stack)
    }
}

Usage

Clone, fork or download the project

$ git clone git@github.com:JohnAlonso/aws-lambda-es7.git
$ cd aws-lambda-es7 && npm install

Configuration

Create a src/Config/local.js configuration file for local development and access environment variables by importing the Config.

import Config from './src/Config'

const config = Config.load()
// Access config variables
console.log(config.service.example)

Mocking a Lambda event

In order to test how Lambda is going to handle a request, a default SNS event Lambda is provided in mock/SNS-event.json (Feel free to create new or override the default event). The following command will execute the handler method from the index.js and inject the context and the AWS event.

$ npm run mock

Testing

You can also use ES7 JavaScript in your tests easily too. The Mocha testing framework is specified as a dependency by default and can be run using:

$ npm run test

Example: tests/ExampleServiceTest.js

import ExampleService from '../src/Services/ExampleService'
import { assert } from 'chai'

describe('ExampleService', () => {
    describe('#join', () => {
        it('joins two words into a single string', async () => {
            let service = new ExampleService('demo')
            let respose = await service.join('test') // Has a 1.5s timeout

            assert.equal(respose, 'demotest')
        })
    })
})

Deployment

Compile, compress and deploy into aws directly by running (aws-cli needs to be installed). In package.json edit the "deploy" script and add your function name and the AWS region. Run the following command to depoy the code into the specified Lambda function:

$ npm run deploy