feat: add respondWithErrors config

* Changed from `logger.level === 'debug'`
* Now responds with stack trace instead of just message
* Added tests

Author: brettstack

README.md

@@ -47,14 +47,18 @@ app.get('/', (req, res) => {
 
 ## 4.0.0 Goals
 
-1. Improved API - Simpler for end user to use and configure; extensible without breaking backwards compatibility or hurting API
-2. Node.js 8+ only - can upgrade dependencies to latest (Jest); can use latest syntax in source and tests; can use server.listening; future-proof for Node.js 10
-3. Promise resolution mode by default? Requires benchmarking. Otherwise try callback with callbackWaitsForEventLoop=false (configurable by user); requires benchmarking. If context.succeed is still most performant, leave as default.
-4. Additional event sources - currently only supports API Gateway Proxy; should also support Lambda@Edge (https://github.com/awslabs/aws-serverless-express/issues/152) and ALB; have had a customer request for DynamoDB; should make it easy to provide your own IO mapping function.
-5. Multiple header values - can get rid of set-cookie hack
-6. Configure logging - NONE, ERROR, INFO, DEBUG; also include option to respond to 500s with the stack trace instead of empty string currently
-7. Improved documentation
-8. Option to strip base path for custom domains (https://github.com/awslabs/aws-serverless-express/issues/86)
+1. ✅ Improved API - Simpler for end user to use and configure; extensible without breaking backwards compatibility or hurting API
+2. ✅ Node.js 8+ only - can upgrade dependencies to latest (Jest); can use latest syntax in source and tests; can use server.listening; future-proof for Node.js 10
+3. 🗓 Promise resolution mode by default? Requires benchmarking. Otherwise try callback with callbackWaitsForEventLoop=false (configurable by user); requires benchmarking. If context.succeed is still most performant, leave as default.
+4. 🗓 Additional event sources - currently only supports API Gateway Proxy; should also support Lambda@Edge (https://github.com/awslabs/aws-serverless-express/issues/152) and ALB; have had a customer request for DynamoDB; should make it easy to provide your own IO mapping function.
+   1. Added ALB; requires refactoring of common logic, additional tests, example refactor.
+   2. Need to add Lambda@Edge
+   3. Need to add example of doing custom resolver (DynamoDB)
+5. ✅ Multiple header values - can get rid of set-cookie hack
+6. ✅ Configure logging - default winston and allow customers to provide their own; include option to respond to 500s with the stack trace instead of empty string currently
+7. 🗓Improved documentation
+8. ✅ Option to strip base path for custom domains (https://github.com/awslabs/aws-serverless-express/issues/86).
+9.  🗓 Update example to include optional parameter for setting up custom domain
 
 ### Is AWS serverless right for my app?
 

__tests__/unit.js

@@ -162,6 +162,29 @@ describe('forwardConnectionErrorResponseToApiGateway', () => {
       multiValueHeaders: {}
     }))
   })
+  test('responds with 502 status and stack trace', () => {
+    return new Promise(
+      (resolve) => {
+        const context = new MockContext(resolve)
+        const contextResolver = {
+          succeed: (p) => context.succeed(p.response)
+        }
+        awsServerlessExpressTransport.forwardConnectionErrorResponseToApiGateway({
+          error: new Error('There was a connection error...'),
+          resolver: contextResolver,
+          logger,
+          respondWithErrors: true
+        })
+      }
+    ).then(successResponse => {
+      expect(successResponse).toEqual({
+        statusCode: 502,
+        body: successResponse.body,
+        multiValueHeaders: {}
+      })
+      expect(successResponse.body).toContain('Error: There was a connection error...\n    at ')
+    })
+  })
 })
 
 describe('forwardLibraryErrorResponseToApiGateway', () => {
@@ -180,6 +203,29 @@ describe('forwardLibraryErrorResponseToApiGateway', () => {
       multiValueHeaders: {}
     }))
   })
+  test('responds with 500 status and stack trace', () => {
+    return new Promise(
+      (resolve) => {
+        const context = new MockContext(resolve)
+        const contextResolver = {
+          succeed: (p) => context.succeed(p.response)
+        }
+        awsServerlessExpressTransport.forwardLibraryErrorResponseToApiGateway({
+          error: new Error('There was an error...'),
+          resolver: contextResolver,
+          logger,
+          respondWithErrors: true
+        })
+      }
+    ).then(successResponse => {
+      expect(successResponse).toEqual({
+        statusCode: 500,
+        body: successResponse.body,
+        multiValueHeaders: {}
+      })
+      expect(successResponse.body).toContain('Error: There was an error...\n    at ')
+    })
+  })
 })
 
 function getContextResolver (resolve) {

examples/basic-starter/lambda.js

@@ -10,7 +10,8 @@ const binaryMimeTypes = [
 ]
 const ase = awsServerlessExpress.configure({
   app,
-  binaryMimeTypes
+  binaryMimeTypes,
+  respondWithErrors: true
   // loggerConfig: {
   //   level: 'debug'
   // }

package.json

@@ -117,7 +117,7 @@
   "scripts": {
     "test": "jest",
     "test:watch": "jest --watch",
-    "coverage": "jest --coverage",
+    "test:coverage": "jest --coverage",
     "cz": "git-cz",
     "release": "semantic-release",
     "release-local": "node -r dotenv/config node_modules/semantic-release/bin/semantic-release --no-ci --dry-run",

src/index.js

@@ -74,7 +74,8 @@ function proxy ({
   resolutionMode = 'CONTEXT_SUCCEED',
   eventSource = getEventSourceBasedOnEvent({ event }),
   eventFns = getEventFnsBasedOnEventSource({ eventSource }),
-  logger
+  logger,
+  respondWithErrors
 }) {
   logger.debug('Calling proxy', { event, context, resolutionMode, eventSource })
   setCurrentLambdaInvoke({ event, context })
@@ -99,7 +100,8 @@ function proxy ({
         resolver,
         eventSource,
         eventFns,
-        logger
+        logger,
+        respondWithErrors
       })
     } else {
       logger.debug('Server isn\'t listening... Starting server. This is likely a cold-start. If you see this message on every request, you may be calling `awsServerlessExpress.createServer` on every call inside the handler function. If this is the case, consider moving it outside of the handler function for imrpoved performance.')
@@ -113,7 +115,8 @@ function proxy ({
             resolver,
             eventSource,
             eventFns,
-            logger
+            logger,
+            respondWithErrors
           })
         })
     }
@@ -141,6 +144,7 @@ function configure ({
   resolutionMode: configureResolutionMode = 'CONTEXT_SUCCEED',
   eventSource: configureEventSource,
   eventFns: configureEventFns,
+  respondWithErrors: configureRespondWithErrors = false,
   loggerConfig: configureLoggerConfig = {},
   logger: configureLogger = createLogger({
     ...DEFAULT_LOGGER_CONFIG,
@@ -164,7 +168,8 @@ function configure ({
     callback,
     eventSource = configureEventSource,
     eventFns = configureEventFns,
-    logger = configureLogger
+    logger = configureLogger,
+    respondWithErrors = configureRespondWithErrors
   } = {}) => (proxy({
     server,
     event,
@@ -173,7 +178,8 @@ function configure ({
     callback,
     eventSource,
     eventFns,
-    logger
+    logger,
+    respondWithErrors
   })),
   handler: configureHandler = (event, context, callback) => configureProxy({
     event,

src/transport.js

@@ -46,9 +46,9 @@ function forwardResponse ({
     })
 }
 
-function forwardConnectionErrorResponseToApiGateway ({ error, resolver, logger }) {
+function forwardConnectionErrorResponseToApiGateway ({ error, resolver, logger, respondWithErrors }) {
   logger.error('aws-serverless-express connection error: ', error)
-  const body = logger.level === 'debug' ? error.message : ''
+  const body = respondWithErrors ? error.stack : ''
   const errorResponse = {
     statusCode: 502, // "DNS resolution, TCP level errors, or actual HTTP parse errors" - https://nodejs.org/api/http.html#http_http_request_options_callback
     body,
@@ -58,9 +58,10 @@ function forwardConnectionErrorResponseToApiGateway ({ error, resolver, logger }
   resolver.succeed({ response: errorResponse })
 }
 
-function forwardLibraryErrorResponseToApiGateway ({ error, resolver, logger }) {
+function forwardLibraryErrorResponseToApiGateway ({ error, resolver, logger, respondWithErrors }) {
   logger.error('aws-serverless-express error: ', error)
-  const body = logger.level === 'debug' ? error.message : ''
+
+  const body = respondWithErrors ? error.stack : ''
   const errorResponse = {
     statusCode: 500,
     body,
@@ -77,7 +78,8 @@ function forwardRequestToNodeServer ({
   resolver,
   eventSource,
   eventFns = getEventFnsBasedOnEventSource({ eventSource }),
-  logger
+  logger,
+  respondWithErrors
 }) {
   logger.debug('Forwarding request to application...')
   try {
@@ -104,14 +106,16 @@ function forwardRequestToNodeServer ({
       .on('error', (error) => forwardConnectionErrorResponseToApiGateway({
         error,
         resolver,
-        logger
+        logger,
+        respondWithErrors
       }))
       .end()
   } catch (error) {
     forwardLibraryErrorResponseToApiGateway({
       error,
       resolver,
-      logger
+      logger,
+      respondWithErrors
     })
   }
 }