docs: add UPGRADE.md

UPGRADE.md

@@ -0,0 +1,35 @@
+## From 3.x to 4.x
+
+```javascript
+// 3.x
+const awsServerlessExpress = require('aws-serverless-express')
+const app = require('./app')
+
+const binaryMimeTypes = [
+  'image/*'
+]
+const server = awsServerlessExpress.createServer(app, null, binaryMimeTypes)
+
+exports.handler = (event, context) => { awsServerlessExpress.proxy(server, event, context) }
+```
+
+```javascript
+// 4.x
+const serverlessExpress = require('@vendia/serverless-express')
+const app = require('./app')
+
+exports.handler = serverlessExpress({ app }).handler
+```
+
+In v4.x, `binaryMimeTypes` isn't required as the `isBase64Encoded` Lambda response value is automatically determined based on the `content-encoding` and `content-type` headers returned by your application. If you need additional control over this, you can specify `binarySettings`:
+
+```javascript
+serverlessExpress({
+  app,
+  binarySettings: {
+    isBinary: ({ headers }) => true,
+    contentTypes: [],
+    contentEncodings: []
+  }
+})
+```

src/configure.d.ts

@@ -11,7 +11,7 @@ interface ConfigureParams {
 
 interface BinarySettings {
   isBinary?: Function | boolean,
-  contentTypes: string[]
+  contentTypes?: string[]
 }
 
 interface ConfigureResult {

src/proxy.d.ts

@@ -3,12 +3,12 @@ import { RequestListener } from "http"
 interface ProxyParams {
   app: RequestListener,
   binaryMimeTypes?: string[],
-  binarySettings: BinarySettings
+  binarySettings?: BinarySettings
 }
 
 interface BinarySettings {
   isBinary?: Function | boolean,
-  contentTypes: string[]
+  contentTypes?: string[]
 }
 
 declare function proxy(proxyParams: ProxyParams): Promise<any>