@evokegroup/aws

AWS utilities

Requires NodeJS 18+

Class: LambdaEvent

Properties

| Property | Type | Description | | -------- | ---- | ----------- | | event | object | The event data from Lambda |

Class: ApiGatewayEvent

extends LambdaEvent

Properties

| Property | Type | Description | | -------- | ---- | ----------- | | headers | object | The event headers | | stageVariables | object | The stage variables sent into the event by API Gateway |

Methods

getBody()

Returns the event request body.

setBody(value)

Overwrite the event request body.

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | value | * | | The body value. Will be stringified. |

getBodyJSON()

Returns the event request body as JSON or Error if the data cannot be parsed.

isJsonRequest()

Returns true if the Content-Type header is set to application/json

getHeader(name)

Gets a header by a case-insensitive name.

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | name | string | | The case-insensitive header name |

setHeader(name, value)

Sets a header.

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | name | string | | The case-insensitive header name | | value | string | | The header value |

getStage()

Gets the stage sent by API Gateway

getStageVariable(name)

Gets a stage variable by name. Returns null if not found.

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | name | string | | The stage variable name |

setStageVariable(name, value)

Overrides a stage variable.

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | name | string | | The stage variable name | | value | string | | The stage variable value |

Class: Config

Base class for configurations classes that can pass their configuration values via an object

Methods

init(config = this)

Initializes the configuration properties.

set(config = {})

Sets properties.

initProperty(name, value)

Initializes a single property

| Parameter | Type | Description | | --------- | ---- | ----------- | | name | string | The property name | | value | * | The default property value |

getTypedEnvValueOrDefault(value, defaultValue)

Attempts to convert value to the defaultValue type. If defaultValue is a function, value will be passed as the argument and the result will be returned.

| Parameter | Type | Description | | --------- | ---- | ----------- | | value | * | The value | | defaultValue | * | The default typed value to fallback on |

Class: EnvironmentConfig

extends Config

Base class for configurations classes using environment variables (process.env)

Class: LambdaConfig

extends EnvironmentConfig

Base class for configurations classes within a Lambda function

constructor(event)

| Parameters | Type | Default | Description | | ---------- | ---- | ------- | ----------- | | event | EvokeAws.LambdaEvent, object | | The event data passed to the Lambda function |

const { LambdaConfig, SuccessResponse } = require('@evokegroup/aws');

class MyConfig extends LambdaConfig {
  site = null;
  environment = null;

  constructor(event) {
    super(event); 
    this.init();
  }
}

export const handler = async (event) => {
  return new Promise((resolve, reject) => {
    const config = new MyConfig(event);
    // do stuff
    resolve(SuccessResponse.json());
  });
};

Properties

event

The EvokeAws.LambdaEvent created from the event data passed to the function

Class: ApiGatewayConfig

extends EnvironmentConfig

Base class for configurations classes within a Lambda function being exexuted via API Gateway and using stage variables

Class: LambdaResponse

A basic Lambda response object.

{
  statusCode: 200,
  headers: {
    "Access-Control-Allow-Origin": "*"
  },
  body: "Hello world",
  isBase64Encoded: false
}

constructor(object)

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | statusCode | number | 200 | The HTTP status code | | headers | object | { "Access-Control-Allow-Origin": "*" } | The response headers. These headers will be merged with the default headers. | | body | string | | The response body | | isBase64Encoded | boolean | false | The body is base64 encoded |

// Return a base64 encoded Buffer
import { LambdaResponse } from '@evokegroup/aws';
export const handler = async (event) => {
  return new Promise((resolve, reject) => {
    resolve(LambdaResponse.json({ body: Buffer.from('data', 'ascii'), isBase64Encoded: true }));
  });
}

Methods

serialize()

Serializes the response.

toJSON()

See serialize.

Class: JsonResponse

extends LambdaResponse

Base class for JSON-based responses.

{
  statusCode: 200,
  headers: {
    "Access-Control-Allow-Origin": "*",
    "Content-Type": "application/json"
  },
  body: "{\"success\":true,\"message\":\"OK\",\"data\":{}}",
  isBase64Encoded: false
}

constructor(object)

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | statusCode | number | 200 | The HTTP status code | | headers | object | { "Access-Control-Allow-Origin": "*" } | The response headers. These headers will be merged with the default headers. | | message | string | "" | | | data | object | null | |

Class: SuccessResponse

extends JsonResponse

Creates a JsonResponse with a default statusCode = 200 and body success = true.

constructor(object)

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | statusCode | number | 400 | The HTTP status code | | headers | object | { "Content-Type": "application/json" } | See EvokeAws.LambdaResponse | | message | string | "" | The response message | | data | object | null | An object to send back in the response |

const { SuccessResponse } = require('@evokegroup/aws');

export const handler = async (event) => {
  return new Promise((resolve, reject) => {
    resolve(SuccessResponse.json());
  });
};

Class: ErrorResponse

extends JsonResponse

Creates a JsonResponse with a default statusCode = 400 and body success = false.

{
  statusCode: 400,
  headers: {
    "Access-Control-Allow-Origin": "*",
    "Content-Type": "application/json"
  },
  body: "{\"success\":false,\"message\":\"An error has occurred.\",\"data\":null}",
  isBase64Encoded: false
}

constructor(object)

| Parameter | Type | Default | Description | | --------- | ---- | ------- | ----------- | | statusCode | number | 400 | The HTTP status code | | headers | object | { "Content-Type": "application/json" } | See EvokeAws.LambdaResponse | | message | string | "" | The response message | | data | object | null | An object to send back in the response | | err | object | null | Any error information |

const { ErrorResponse } = require('@evokegroup/aws');

export const handler = async (event) => {
  return new Promise((resolve, reject) => {
    resolve(ErrorResponse.json({ statusCode: 403, message: 'Unauthorized' }));
  });
};