feat: add support for Step Functions (#668)

README.md

@@ -281,6 +281,8 @@ serverlessExpress({
  'AWS_SQS': '/sqs'
  'AWS_EVENTBRIDGE': '/eventbridge',
  'AWS_KINESIS_DATA_STREAM': '/kinesis',
+ 'AWS_S3': '/s3',
+ 'AWS_STEP_FUNCTIONS': '/step-functions',
  }
 })
 ```

src/configure.d.ts

@@ -3,7 +3,7 @@ import { Handler } from 'aws-lambda';
 import { Logger } from './logger';
 import Framework from './frameworks';
 
-type EventSources = 'AWS_SNS' | 'AWS_DYNAMODB' | 'AWS_EVENTBRIDGE' | 'AWS_SQS' | 'AWS_KINESIS_DATA_STREAM' | 'AWS_S3';
+type EventSources = 'AWS_SNS' | 'AWS_DYNAMODB' | 'AWS_EVENTBRIDGE' | 'AWS_SQS' | 'AWS_KINESIS_DATA_STREAM' | 'AWS_S3' | 'AWS_STEP_FUNCTIONS';
 
 interface EventSource {
  getRequest?: any; // TODO:

src/event-sources/aws/step-functions.js

@@ -0,0 +1,27 @@
+const getRequestValuesFromStepFunctions = ({ event }) => {
+ const method = 'POST'
+ const headers = { host: 'stepfunctions.amazonaws.com' }
+ const body = event
+
+ return {
+ method,
+ headers,
+ body
+ }
+}
+
+const getResponseToStepFunctions = ({
+ body,
+ isBase64Encoded = false
+}) => {
+ if (isBase64Encoded) {
+ throw new Error('base64 encoding is not supported')
+ }
+
+ return JSON.parse(body)
+}
+
+module.exports = {
+ getRequest: getRequestValuesFromStepFunctions,
+ getResponse: getResponseToStepFunctions
+}

src/event-sources/azure/http-function-runtime-v4.js

@@ -1,6 +1,6 @@
 const { getRequest, getResponse } = require('./http-function-runtime-v3')
 
 module.exports = {
- getRequest: getRequest,
- getResponse: getResponse
+ getRequest,
+ getResponse
 }

src/event-sources/index.js

@@ -10,6 +10,7 @@ const azureHttpFunctionV4EventSource = require('./azure/http-function-runtime-v4
 const awsEventBridgeEventSource = require('./aws/eventbridge')
 const awsKinesisEventSource = require('./aws/kinesis')
 const awsS3 = require('./aws/s3')
+const awsStepFunctionsEventSource = require('./aws/step-functions')
 
 function getEventSource ({ eventSourceName }) {
  switch (eventSourceName) {
@@ -37,6 +38,8 @@ function getEventSource ({ eventSourceName }) {
  return awsKinesisEventSource
  case 'AWS_S3':
  return awsS3
+ case 'AWS_STEP_FUNCTIONS':
+ return awsStepFunctionsEventSource
  default:
  throw new Error('Couldn\'t detect valid event source.')
  }

src/event-sources/utils.js

@@ -127,6 +127,10 @@ function getEventSourceNameBasedOnEvent ({
  return 'AWS_EVENTBRIDGE'
  }
 
+ if (event.context && event.context.Execution && event.context.State && event.context.StateMachine) {
+ return 'AWS_STEP_FUNCTIONS'
+ }
+
  throw new Error('Unable to determine event source based on event.')
 }