From 85af1ce3319f81aa243536cf909cae59683efd75 Mon Sep 17 00:00:00 2001
From: conico974 <nicodorseuil@yahoo.fr>
Date: Mon, 26 Aug 2024 19:13:08 +0200
Subject: [PATCH] Fix node crashing when used without stream (#498)

* fix for null return

* update version

* fix body already consumed for redirect

* update version

* Create strange-pugs-sort.md
---
 .changeset/strange-pugs-sort.md               |  5 ++++
 packages/open-next/src/core/requestHandler.ts | 11 ++++-----
 packages/open-next/src/core/routing/util.ts   |  4 +++-
 packages/open-next/src/wrappers/aws-lambda.ts | 23 ++++++++++++++++++-
 4 files changed, 35 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/strange-pugs-sort.md

diff --git a/.changeset/strange-pugs-sort.md b/.changeset/strange-pugs-sort.md
new file mode 100644
index 00000000..a9dc1c85
--- /dev/null
+++ b/.changeset/strange-pugs-sort.md
@@ -0,0 +1,5 @@
+---
+"open-next": patch
+---
+
+Fix node crashing when used without stream
diff --git a/packages/open-next/src/core/requestHandler.ts b/packages/open-next/src/core/requestHandler.ts
index 0e83cc0e..5a5342e6 100644
--- a/packages/open-next/src/core/requestHandler.ts
+++ b/packages/open-next/src/core/requestHandler.ts
@@ -7,7 +7,6 @@ import {
 } from "http/index.js";
 import { InternalEvent, InternalResult } from "types/open-next";
 import { DetachedPromiseRunner } from "utils/promise";
-import { fromReadableStream } from "utils/stream";
 
 import { debug, error, warn } from "../adapters/logger";
 import { convertRes, createServerResponse, proxyRequest } from "./routing/util";
@@ -73,12 +72,12 @@ export async function openNextHandler(
       );
       res.statusCode = preprocessResult.statusCode;
       res.flushHeaders();
-      const body = await fromReadableStream(
-        preprocessResult.body,
-        preprocessResult.isBase64Encoded,
-      );
-      res.write(body);
+      const [bodyToConsume, bodyToReturn] = preprocessResult.body.tee();
+      for await (const chunk of bodyToConsume) {
+        res.write(chunk);
+      }
       res.end();
+      preprocessResult.body = bodyToReturn;
     }
     return preprocessResult;
   } else {
diff --git a/packages/open-next/src/core/routing/util.ts b/packages/open-next/src/core/routing/util.ts
index bae3d413..c7b25dd4 100644
--- a/packages/open-next/src/core/routing/util.ts
+++ b/packages/open-next/src/core/routing/util.ts
@@ -81,7 +81,9 @@ export function convertRes(res: OpenNextNodeResponse): InternalResult {
       ? headers["content-type"][0]
       : headers["content-type"],
   );
-  const body = Readable.toWeb(res);
+  // We cannot convert the OpenNextNodeResponse to a ReadableStream directly
+  // You can look in the `aws-lambda.ts` file for some context
+  const body = Readable.toWeb(Readable.from(res.getBody()));
   return {
     type: "core",
     statusCode,
diff --git a/packages/open-next/src/wrappers/aws-lambda.ts b/packages/open-next/src/wrappers/aws-lambda.ts
index 3477e9ff..e4fa8afc 100644
--- a/packages/open-next/src/wrappers/aws-lambda.ts
+++ b/packages/open-next/src/wrappers/aws-lambda.ts
@@ -1,3 +1,5 @@
+import { Writable } from "node:stream";
+
 import type {
   APIGatewayProxyEvent,
   APIGatewayProxyEventV2,
@@ -6,6 +8,7 @@ import type {
   CloudFrontRequestEvent,
   CloudFrontRequestResult,
 } from "aws-lambda";
+import { StreamCreator } from "http/openNextResponse";
 import type { WrapperHandler } from "types/open-next";
 
 import { WarmerEvent, WarmerResponse } from "../adapters/warmer-function";
@@ -40,7 +43,25 @@ const handler: WrapperHandler =
 
     const internalEvent = await converter.convertFrom(event);
 
-    const response = await handler(internalEvent);
+    //TODO: create a simple reproduction and open an issue in the node repo
+    //This is a workaround, there is an issue in node that causes node to crash silently if the OpenNextNodeResponse stream is not consumed
+    //This does not happen everytime, it's probably caused by suspended component in ssr (either via <Suspense> or loading.tsx)
+    //Everyone that wish to create their own wrapper without a StreamCreator should implement this workaround
+    //This is not necessary if the underlying handler does not use OpenNextNodeResponse (At the moment, OpenNextNodeResponse is used by the node runtime servers and the image server)
+    const fakeStream: StreamCreator = {
+      writeHeaders: () => {
+        return new Writable({
+          write: (_chunk, _encoding, callback) => {
+            callback();
+          },
+        });
+      },
+      onFinish: () => {
+        // Do nothing
+      },
+    };
+
+    const response = await handler(internalEvent, fakeStream);
 
     return converter.convertTo(response, event);
   };