types: declare global awslambda stream APIs

src/@types/awslambda/index.d.ts

@@ -0,0 +1,17 @@
+import type { APIGatewayProxyEventV2, Context, Handler } from 'aws-lambda'
+
+declare global {
+  namespace awslambda {
+    export namespace HttpResponseStream {
+      function from(writable: NodeJS.WritableStream, metadata: any): NodeJS.WritableStream
+    }
+
+    export type ResponseStream = NodeJS.WritableStream & {
+      setContentType: (type: string) => void
+    }
+
+    export type StreamifyHandler = (event: APIGatewayProxyEventV2, responseStream: ResponseStream, context: Context) => Promise<any>
+
+    export function streamifyResponse(handler: StreamifyHandler): Handler<APIGatewayProxyEventV2>
+  }
+}