fix: content type request bug in http serializer (middyjs#335)

* fix: tests not waiting for callbacks

* fix: content-type skip using request headers not response headers

* version bump and handling Cannot read property headers of undefined

lerna.json

@@ -3,5 +3,5 @@
   "packages": [
     "packages/*"
   ],
-  "version": "1.0.0-alpha.31"
+  "version": "1.0.0-alpha.32"
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "middy-monorepo",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "🛵 The stylish Node.js middleware engine for AWS Lambda",
   "engines": {
     "node": ">=6.10"

packages/cache/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/cache",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Cache middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/core/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/core",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "🛵 The stylish Node.js middleware engine for AWS Lambda (core package)",
   "engines": {
     "node": ">=6.10"

packages/do-not-wait-for-empty-event-loop/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/do-not-wait-for-empty-event-loop",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Middleware for the middy framework that allows to easily disable the wait for empty event loop in a Lambda function",
   "engines": {
     "node": ">=6.10"

packages/error-logger/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/error-logger",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Input and output logger middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/function-shield/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/function-shield",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Hardens AWS Lambda execution environment",
   "engines": {
     "node": ">=6.10"

packages/http-content-negotiation/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-content-negotiation",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Http content negotiation middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-cors/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-cors",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "CORS (Cross-Origin Resource Sharing) middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-error-handler/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-error-handler",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Http error handler middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-event-normalizer/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-event-normalizer",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Http event normalizer middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-header-normalizer/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-header-normalizer",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Http header normalizer middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-json-body-parser/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-json-body-parser",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Http JSON body parser middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-partial-response/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-partial-response",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Http partial response middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-response-serializer/__tests__/index.js

@@ -34,7 +34,7 @@ describe('📦  Middleware Http Response Serializer', () => {
       ['CONTENT-TYPE']
     ])(
       '%s skips response serialization',
-      (key) => {
+      (key, done) => {
         const handlerResponse = Object.assign({}, createHttpResponse(), {
           headers: {
             [key]: 'text/plain'
@@ -46,6 +46,7 @@ describe('📦  Middleware Http Response Serializer', () => {
 
         handler({}, {}, (_, response) => {
           expect(response).toEqual(handlerResponse)
+          done()
         })
       })
   })
@@ -57,7 +58,7 @@ describe('📦  Middleware Http Response Serializer', () => {
       ['text/plain, text/x-c', 'Hello World']
     ])(
       '%s returns %s',
-      (accept, result) => {
+      (accept, result, done) => {
         const handler = middy((event, context, cb) => cb(null, createHttpResponse()))
 
         handler.use(httpResponseSerializer(standardConfiguration))
@@ -70,11 +71,12 @@ describe('📦  Middleware Http Response Serializer', () => {
 
         handler(event, {}, (_, response) => {
           expect(response.body).toEqual(result)
+          done()
         })
       })
   })
 
-  test('It should use `event.requiredContentType` instead of accept headers', () => {
+  test('It should use `event.requiredContentType` instead of accept headers', done => {
     const handler = middy((event, context, cb) => {
       event.requiredContentType = 'text/plain'
 
@@ -97,10 +99,11 @@ describe('📦  Middleware Http Response Serializer', () => {
         },
         body: 'Hello World'
       })
+      done()
     })
   })
 
-  test('It should use the default when no accept preferences are given', () => {
+  test('It should use the default when no accept preferences are given', done => {
     const handler = middy((event, context, cb) =>
       cb(null, createHttpResponse())
     )
@@ -115,10 +118,11 @@ describe('📦  Middleware Http Response Serializer', () => {
         },
         body: '{"message":"Hello World"}'
       })
+      done()
     })
   })
 
-  test('It should use `event.preferredContentType` instead of the default', () => {
+  test('It should use `event.preferredContentType` instead of the default', done => {
     const handler = middy((event, context, cb) => {
       event.preferredContentType = 'text/plain'
 
@@ -135,10 +139,11 @@ describe('📦  Middleware Http Response Serializer', () => {
         },
         body: 'Hello World'
       })
+      done()
     })
   })
 
-  test('It should pass-through when no preference or default is found', () => {
+  test('It should pass-through when no preference or default is found', done => {
     const handler = middy((event, context, cb) =>
       cb(null, createHttpResponse())
     )
@@ -152,10 +157,37 @@ describe('📦  Middleware Http Response Serializer', () => {
         statusCode: 200,
         body: 'Hello World'
       })
+      done()
     })
   })
 
-  test('It should replace the response object when the serializer returns an object', () => {
+  test('It should not pass-through when request content-type is set', done => {
+    const handler = middy((event, context, cb) =>
+      cb(null, createHttpResponse())
+    )
+
+    handler.use(httpResponseSerializer(standardConfiguration))
+
+    const event = {
+      headers: {
+        'Content-Type': 'application/xml'
+      }
+    }
+
+    handler(event, {}, (err, response) => {
+      if (err) throw err
+      expect(response).toEqual({
+        statusCode: 200,
+        headers: {
+          'Content-Type': standardConfiguration.default
+        },
+        body: '{"message":"Hello World"}'
+      })
+      done()
+    })
+  })
+
+  test('It should replace the response object when the serializer returns an object', done => {
     const handler = middy((event, context, cb) =>
       cb(null, createHttpResponse())
     )
@@ -182,10 +214,11 @@ describe('📦  Middleware Http Response Serializer', () => {
         body: 'SGVsbG8gV29ybGQ=',
         isBase64Encoded: true
       })
+      done()
     })
   })
 
-  test('It should work with `http-error-handler` middleware', () => {
+  test('It should work with `http-error-handler` middleware', done => {
     const handler = middy((event, context, cb) => {
       throw new createError.UnprocessableEntity()
     })
@@ -202,6 +235,32 @@ describe('📦  Middleware Http Response Serializer', () => {
           'Content-Type': 'application/json'
         }
       })
+      done()
+    })
+  })
+
+  test('It should not crash if the response is undefined', done => {
+    const handler = middy((event, context, cb) =>
+      cb(null, undefined)
+    )
+
+    handler.use(httpResponseSerializer(standardConfiguration))
+
+    const event = {
+      headers: {
+        'Content-Type': 'application/xml'
+      }
+    }
+
+    handler(event, {}, (err, response) => {
+      if (err) throw err
+      expect(response).toEqual({
+        headers: {
+          'Content-Type': standardConfiguration.default
+        },
+        body: '{}'
+      })
+      done()
     })
   })
 })

packages/http-response-serializer/index.js

@@ -10,10 +10,11 @@ const getNormalisedHeaders = (source) => Object
 
 const middleware = (opts, handler, next) => {
   // normalise headers for internal use only
-  const headers = getNormalisedHeaders(handler.event.headers || {})
+  const requestHeaders = getNormalisedHeaders((handler.event && handler.event.headers) || {})
+  const responseHeaders = getNormalisedHeaders((handler.response && handler.response.headers) || {})
 
   // skip serialization when content-type is already set
-  if (headers['content-type']) {
+  if (responseHeaders['content-type']) {
     return next()
   }
 
@@ -24,7 +25,7 @@ const middleware = (opts, handler, next) => {
     types = [].concat(handler.event.requiredContentType)
   } else {
     types = [].concat(
-      (headers['accept'] && Accept.mediaTypes(headers['accept'])) || [],
+      (requestHeaders['accept'] && Accept.mediaTypes(requestHeaders['accept'])) || [],
       handler.event.preferredContentType || [],
       opts.default || []
     )
@@ -41,6 +42,9 @@ const middleware = (opts, handler, next) => {
 
     if (!test) { return false }
 
+    // if the response is null or undefined, normalizes it back to an object
+    handler.response = handler.response || {}
+
     // set header
     handler.response.headers = Object.assign({}, handler.response.headers, { 'Content-Type': type })
 

packages/http-response-serializer/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-response-serializer",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Http response serializer middleware for the middy framework",
   "engines": {
     "node": ">=6.10"

packages/http-security-header/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@middy/http-security-header",
-  "version": "1.0.0-alpha.31",
+  "version": "1.0.0-alpha.32",
   "description": "Applies best practice security headers to responses. It's a simplified port of HelmetJS",
   "engines": {
     "node": ">=6.10"