feat: add support for SNS and DynamoDB event sources (#468)

Author: cnuss

README.md

@@ -170,6 +170,50 @@ serverlessExpress({
 })
 ```
 
+#### eventSourceRoutes
+
+Introduced in `@vendia/[email protected]` native support for `aws:sns` and `aws:dynamodb` events were introduced.
+
+A single function can be configured to handle events from SNS and DynamoDB, as well as the previously supported events.
+
+Assuming the following function configuration in `serverless.yml`:
+
+```yaml
+functions:
+  lambda-handler:
+    handler: src/lambda.handler
+    events:
+      - http:
+          path: /
+          method: get
+      - sns:
+          topicName: my-topic
+      - stream:
+          type: dynamodb
+          arn: arn:aws:dynamodb:us-east-1:012345678990:table/my-table/stream/2021-07-15T15:05:51.683
+```
+
+And the following configuration:
+
+```js
+serverlessExpress({
+  app,
+  eventSourceRoutes: {
+    'AWS_SNS': '/sns',
+    'AWS_DYNAMODB': '/dynamodb'
+  }
+})
+```
+
+Events from SNS and DynamoDB will `POST` to the routes configured in Express to handle `/sns` and `/dynamodb`,
+respectively.
+
+Also, to ensure the events propagated from an internal event and not externally, it is **highly recommended** to 
+ensure the `Host` header matches:
+
+ - SNS: `sns.amazonaws.com`
+ - DynamoDB: `dynamodb.amazonaws.com`
+
 ### logSettings
 
 Specify log settings that are passed to the default logger. Currently, you can only set the log `level`.

__tests__/unit.api-gateway-v2.js

@@ -1,5 +1,5 @@
 const eventSources = require('../src/event-sources')
-const testUtils = require('../src/event-sources/utils.test')
+const testUtils = require('./utils')
 
 const apiGatewayEventSource = eventSources.getEventSource({
   eventSourceName: 'AWS_API_GATEWAY_V2'
@@ -15,7 +15,7 @@ test('request has correct headers', () => {
 })
 
 function getReq () {
-  const event = testUtils.sam_httpapi_event
+  const event = testUtils.samHttpApiEvent
   const request = apiGatewayEventSource.getRequest({ event })
   return request
 }

__tests__/unit.dynamodb.js

@@ -0,0 +1,20 @@
+const eventSources = require('../src/event-sources')
+const testUtils = require('./utils')
+
+const dynamodbEventSource = eventSources.getEventSource({
+  eventSourceName: 'AWS_DYNAMODB'
+})
+
+test('request is correct', () => {
+  const req = getReq()
+  expect(typeof req).toEqual('object')
+  expect(req.headers).toEqual({ host: 'dynamodb.amazonaws.com' })
+  expect(req.body).toEqual(testUtils.dynamoDbEvent)
+  expect(req.method).toEqual('POST')
+})
+
+function getReq () {
+  const event = testUtils.dynamoDbEvent
+  const request = dynamodbEventSource.getRequest({ event })
+  return request
+}

__tests__/unit.js

@@ -112,15 +112,17 @@ test('getRequestResponse: without headers', async () => {
 describe('respondToEventSourceWithError', () => {
   test('responds with 500 status', () => {
     return new Promise(
-      (resolve) => {
-        const context = new MockContext(resolve)
+      (resolve, reject) => {
+        const context = new MockContext(resolve, reject)
         const contextResolver = {
-          succeed: (p) => context.succeed(p.response)
+          succeed: (p) => context.succeed(p.response),
+          fail: (p) => context.fail(p.error)
         }
         serverlessExpressTransport.respondToEventSourceWithError({
           error: new Error('ERROR'),
           resolver: contextResolver,
           log,
+          eventSourceName: 'AWS_API_GATEWAY_V1',
           eventSource: apiGatewayEventSource
         })
       }
@@ -133,16 +135,18 @@ describe('respondToEventSourceWithError', () => {
   })
   test('responds with 500 status and stack trace', () => {
     return new Promise(
-      (resolve) => {
-        const context = new MockContext(resolve)
+      (resolve, reject) => {
+        const context = new MockContext(resolve, reject)
         const contextResolver = {
-          succeed: (p) => context.succeed(p.response)
+          succeed: (p) => context.succeed(p.response),
+          fail: (p) => context.fail(p.error)
         }
         serverlessExpressTransport.respondToEventSourceWithError({
           error: new Error('There was an error...'),
           resolver: contextResolver,
           log,
           respondWithErrors: true,
+          eventSourceName: 'AWS_API_GATEWAY_V1',
           eventSource: apiGatewayEventSource
         })
       }
@@ -158,10 +162,11 @@ describe('respondToEventSourceWithError', () => {
   })
 })
 
-function getContextResolver (resolve) {
-  const context = new MockContext(resolve)
+function getContextResolver (resolve, reject) {
+  const context = new MockContext(resolve, reject)
   const contextResolver = {
-    succeed: (p) => context.succeed(p.response)
+    succeed: (p) => context.succeed(p.response),
+    fail: (p) => context.fail(p.error)
   }
 
   return contextResolver
@@ -174,8 +179,8 @@ describe.skip('forwardResponse: content-type encoding', () => {
     const { requestResponse } = await getReqRes(multiValueHeaders)
     const response = new ServerlessResponse(requestResponse.request)
     return new Promise(
-      (resolve) => {
-        const contextResolver = getContextResolver(resolve)
+      (resolve, reject) => {
+        const contextResolver = getContextResolver(resolve, reject)
         serverlessExpressTransport.forwardResponse({
           binaryMimeTypes,
           response,
@@ -199,8 +204,8 @@ describe.skip('forwardResponse: content-type encoding', () => {
     const body = 'hello world'
     const response = new ServerlessResponse(200, multiValueHeaders, body)
     return new Promise(
-      (resolve) => {
-        const contextResolver = getContextResolver(resolve)
+      (resolve, reject) => {
+        const contextResolver = getContextResolver(resolve, reject)
         serverlessExpressTransport.forwardResponse({
           binaryMimeTypes,
           response,
@@ -223,8 +228,8 @@ describe.skip('forwardResponse: content-type encoding', () => {
     const body = JSON.stringify({ hello: 'world' })
     const response = new ServerlessResponse(200, multiValueHeaders, body)
     return new Promise(
-      (resolve) => {
-        const contextResolver = getContextResolver(resolve)
+      (resolve, reject) => {
+        const contextResolver = getContextResolver(resolve, reject)
         serverlessExpressTransport.forwardResponse({
           binaryMimeTypes,
           response,
@@ -247,8 +252,8 @@ describe.skip('forwardResponse: content-type encoding', () => {
     const body = 'hello world'
     const response = new ServerlessResponse(200, multiValueHeaders, body)
     return new Promise(
-      (resolve) => {
-        const contextResolver = getContextResolver(resolve)
+      (resolve, reject) => {
+        const contextResolver = getContextResolver(resolve, reject)
         serverlessExpressTransport.forwardResponse({
           binaryMimeTypes,
           response,
@@ -271,8 +276,8 @@ describe.skip('forwardResponse: content-type encoding', () => {
     const body = 'hello world'
     const response = new ServerlessResponse(200, multiValueHeaders, body)
     return new Promise(
-      (resolve) => {
-        const contextResolver = getContextResolver(resolve)
+      (resolve, reject) => {
+        const contextResolver = getContextResolver(resolve, reject)
         serverlessExpressTransport.forwardResponse({
           binaryMimeTypes,
           response,
@@ -293,8 +298,8 @@ describe.skip('forwardResponse: content-type encoding', () => {
 describe('makeResolver', () => {
   test('CONTEXT (specified)', () => {
     return new Promise(
-      (resolve) => {
-        const context = new MockContext(resolve)
+      (resolve, reject) => {
+        const context = new MockContext(resolve, reject)
         const contextResolver = makeResolver({
           context,
           resolutionMode: 'CONTEXT'

__tests__/unit.sns.js

@@ -0,0 +1,20 @@
+const eventSources = require('../src/event-sources')
+const testUtils = require('./utils')
+
+const snsEventSource = eventSources.getEventSource({
+  eventSourceName: 'AWS_SNS'
+})
+
+test('request is correct', () => {
+  const req = getReq()
+  expect(typeof req).toEqual('object')
+  expect(req.headers).toEqual({ host: 'sns.amazonaws.com' })
+  expect(req.body).toEqual(testUtils.snsEvent)
+  expect(req.method).toEqual('POST')
+})
+
+function getReq () {
+  const event = testUtils.snsEvent
+  const request = snsEventSource.getRequest({ event })
+  return request
+}