aws-lambda-utils

An opinionated, decorated-based approach to reduce code required to create AWS Lambda handler functions.

Available Decorators

$3

A decorator that focuses to process AWS Lambda handler with ProxyIntegration.
It will try to make sure to return a valid response that APIGateway can cope with, i.e.:

``typescript
let res: {
statusCode: number;
headers: Record;
body?: string;
};
`

Lambda Proxy currently supports the following features:

1. cors header injection
1. body parsing
1. response transformation
1. statusCode
1. body
1. error handling
1. user extraction

#### cors header injection

Will inject the following cors headers with the event.headers ultimatively returned by the decorated handler:

`
{
"Access-Control-Allow-Origin": "*",
"Access-Control-Allow-Credentials": true
}
`

Usage:

`
@LambdaProxy()
class TestClass {
public static injectCors(_event: any, _context: any) {
return Promise.resolve();
}
}

console.dir(TestClass.injectCors().headers)
# > {
# > 'Access-Control-Allow-Origin': '*',
# > 'Access-Control-Allow-Credentials': true
# > }
`

TBD:

- make injection optional
- allow custom header injection

#### body parsing

With the help of the body attribute in the LambdaProxyOpts,
we can validate and transform the value provided in event.body:

`typescript

``

In order to enable comfortable parsing & transformation of json-based input data,
we are using class-transformer and class-validator.