feat: auto-detect binary response and add binarySettings

binaryMimeTypes now deprecated

Author: brett-vendia

examples/basic-starter-api-gateway-v2/src/lambda.js

@@ -2,15 +2,4 @@ require('source-map-support/register')
 const serverlessExpress = require('@vendia/serverless-express')
 const app = require('./app')
 
-// NOTE: If you get ERR_CONTENT_DECODING_FAILED in your browser, this is likely
-// due to a compressed response (e.g. gzip) which has not been handled correctly
-// by serverless-express and/or API Gateway. Add the necessary MIME types to
-// binaryMimeTypes below, then redeploy (`npm run package-deploy`)
-const binaryMimeTypes = [
-  '*/*'
-]
-
-exports.handler = serverlessExpress({
-  app,
-  binaryMimeTypes
-}).handler
+exports.handler = serverlessExpress({ app }).handler

package-lock.json

@@ -137,12 +137,9 @@
     "lint": "eslint src examples",
     "install-example-dependencies": "cd examples && npm install --prefix basic-starter-api-gateway-v1 basic-starter-api-gateway-v1 && cd .."
   },
-  "dependencies": {
-    "type-is": "^1.6.16"
-  },
   "config": {
     "commitizen": {
       "path": "cz-conventional-changelog"
     }
   }
-}
+}

package.json

@@ -5,7 +5,13 @@ import ProxyParams from "./proxy"
 
 interface ConfigureParams {
   app: RequestListener,
-  binaryMimeTypes?: string[]
+  binaryMimeTypes?: string[],
+  binarySettings: BinarySettings
+}
+
+interface BinarySettings {
+  isBinary?: Function | boolean,
+  contentTypes: string[]
 }
 
 interface ConfigureResult {

src/configure.d.ts

@@ -5,7 +5,8 @@ const proxy = require('./proxy')
 function configure ({
   app: configureApp,
   framework: configureFramework = getFramework({ app: configureApp }),
-  binaryMimeTypes: configureBinaryMimeTypes = [],
+  binaryMimeTypes: configureBinaryMimeTypes,
+  binarySettings: configureBinarySettings,
   resolutionMode: configureResolutionMode = 'PROMISE',
   eventSourceName: configureEventSourceName,
   eventSource: configureEventFns,
@@ -20,6 +21,7 @@ function configure ({
     callback,
     eventSourceName = configureEventSourceName,
     binaryMimeTypes = configureBinaryMimeTypes,
+    binarySettings = configureBinarySettings,
     eventSource = configureEventFns,
     log = configureLogger,
     respondWithErrors = configureRespondWithErrors
@@ -32,6 +34,7 @@ function configure ({
     callback,
     eventSourceName,
     binaryMimeTypes,
+    binarySettings,
     eventSource,
     log,
     respondWithErrors

src/configure.js

@@ -0,0 +1,42 @@
+// ATTRIBUTION: https://github.com/dougmoscrop/serverless-http
+
+function isContentEncodingBinary ({ headers, binaryEncodingTypes }) {
+  const contentEncoding = headers['content-encoding']
+
+  if (typeof contentEncoding !== 'string') return false
+
+  return contentEncoding
+    .split(',')
+    .some(value => binaryEncodingTypes.some(binaryEncoding => value.includes(binaryEncoding)))
+}
+
+function getContentType ({ headers }) {
+  const contentTypeHeader = headers['content-type'] || ''
+
+  // only compare mime type; ignore encoding part
+  return contentTypeHeader.split(';')[0]
+}
+
+function isContentTypeBinary ({ headers, binaryContentTypes }) {
+  if (!binaryContentTypes || !Array.isArray(binaryContentTypes)) return false
+
+  const binaryContentTypesRegexes = binaryContentTypes.map(binaryContentType => new RegExp(`^${binaryContentType.replace(/\*/g, '.*')}$`))
+  const contentType = getContentType({ headers })
+
+  if (!contentType) return false
+
+  return binaryContentTypesRegexes.some(binaryContentType => binaryContentType.test(contentType))
+}
+
+module.exports = function isBinary ({ headers, binarySettings }) {
+  if (binarySettings.isBinary === false) {
+    return false
+  }
+
+  if (typeof binarySettings.isBinary === 'function') {
+    return binarySettings.isBinary({ headers })
+  }
+
+  return isContentEncodingBinary({ headers, binaryEncodingTypes: binarySettings.contentEncodings }) ||
+    isContentTypeBinary({ headers, binaryContentTypes: binarySettings.contentTypes })
+}

src/is-binary.js

@@ -2,7 +2,13 @@ import { RequestListener } from "http"
 
 interface ProxyParams {
   app: RequestListener,
-  binaryMimeTypes?: string[]
+  binaryMimeTypes?: string[],
+  binarySettings: BinarySettings
+}
+
+interface BinarySettings {
+  isBinary?: Function | boolean,
+  contentTypes: string[]
 }
 
 declare function proxy(proxyParams: ProxyParams): Promise<any>

src/proxy.d.ts

@@ -5,6 +5,16 @@ const { getFramework } = require('./frameworks')
 const makeResolver = require('./make-resolver')
 const { forwardRequestToNodeServer, respondToEventSourceWithError } = require('./transport')
 
+const DEFAULT_BINARY_ENCODINGS = ['gzip', 'deflate', 'br']
+const DEFAULT_BINARY_CONTENT_TYPES = ['image/*']
+
+function getDefaultBinarySettings (deprecatedBinaryMimeTypes) {
+  return {
+    contentTypes: deprecatedBinaryMimeTypes || DEFAULT_BINARY_CONTENT_TYPES,
+    contentEncodings: DEFAULT_BINARY_ENCODINGS
+  }
+}
+
 function proxy ({
   app,
   framework = getFramework({ app }),
@@ -14,6 +24,7 @@ function proxy ({
   resolutionMode = 'PROMISE',
   eventSourceName = getEventSourceNameBasedOnEvent({ event }),
   binaryMimeTypes,
+  binarySettings = getDefaultBinarySettings(binaryMimeTypes),
   eventSource = getEventSource({ eventSourceName }),
   log,
   respondWithErrors
@@ -23,9 +34,14 @@ function proxy ({
     context,
     resolutionMode,
     eventSourceName,
-    binaryMimeTypes,
+    binarySettings,
     respondWithErrors
   })
+
+  if (binaryMimeTypes) {
+    console.warn('{ binaryMimeTypes: [] } is deprecated. base64 encoding is now automatically determined based on response content-type and content-encoding. If you need to manually set binary content types, instead, use { binarySettings: { contentTypes: [] } }')
+  }
+
   setCurrentInvoke({ event, context })
   return new Promise((resolve, reject) => {
     const promise = {
@@ -47,7 +63,7 @@ function proxy ({
         context,
         resolver,
         eventSourceName,
-        binaryMimeTypes,
+        binarySettings,
         eventSource,
         log
       })

src/proxy.js

@@ -1,4 +1,3 @@
-'use strict'
 // ATTRIBUTION: https://github.com/dougmoscrop/serverless-http
 
 const http = require('http')

src/request.js

@@ -1,4 +1,3 @@
-'use strict'
 // ATTRIBUTION: https://github.com/dougmoscrop/serverless-http
 
 const http = require('http')