From 2024c886cc8cade8ccdf5012f1aac31d43516aae Mon Sep 17 00:00:00 2001
From: Josh Larson <josh.larson@shopify.com>
Date: Thu, 26 May 2022 10:48:44 -0500
Subject: [PATCH 1/2] Explicitly set highWaterMark to 0 for ReadableStreams

This is because not all streaming implementations respect the
default behavior of settings highWaterMark to 0 for byte streams.
Being explicit guarantees the intended behavior across runtimes.
---
 .../src/server/ReactDOMFizzServerBrowser.js   | 20 +++++++++++------
 .../src/ReactFlightDOMServerBrowser.js        | 22 ++++++++++++-------
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js b/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js
index 1ae511ede561..b83e63236b30 100644
--- a/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js
+++ b/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js
@@ -53,15 +53,21 @@ function renderToReadableStream(
     });
 
     function onShellReady() {
-      const stream: ReactDOMServerReadableStream = (new ReadableStream({
-        type: 'bytes',
-        pull(controller) {
-          startFlowing(request, controller);
+      const stream: ReactDOMServerReadableStream = (new ReadableStream(
+        {
+          type: 'bytes',
+          pull(controller) {
+            startFlowing(request, controller);
+          },
+          cancel(reason) {
+            abort(request);
+          },
         },
-        cancel(reason) {
-          abort(request);
+        {
+          highWaterMark: 0,
+          size: () => 1,
         },
-      }): any);
+      ): any);
       // TODO: Move to sub-classing ReadableStream.
       stream.allReady = allReady;
       resolve(stream);
diff --git a/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js b/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js
index aeee2d24806d..78f1e9ce84d7 100644
--- a/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js
+++ b/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js
@@ -33,16 +33,22 @@ function renderToReadableStream(
     options ? options.onError : undefined,
     context,
   );
-  const stream = new ReadableStream({
-    type: 'bytes',
-    start(controller) {
-      startWork(request);
+  const stream = new ReadableStream(
+    {
+      type: 'bytes',
+      start(controller) {
+        startWork(request);
+      },
+      pull(controller) {
+        startFlowing(request, controller);
+      },
+      cancel(reason) {},
     },
-    pull(controller) {
-      startFlowing(request, controller);
+    {
+      highWaterMark: 0,
+      size: () => 1,
     },
-    cancel(reason) {},
-  });
+  );
   return stream;
 }
 

From fff3966ad4142f7d8d1535e6733de4c392af8507 Mon Sep 17 00:00:00 2001
From: Josh Larson <josh.larson@shopify.com>
Date: Tue, 31 May 2022 14:36:03 -0500
Subject: [PATCH 2/2] Remove size methods and add FlowFixMe instead

---
 packages/react-dom/src/server/ReactDOMFizzServerBrowser.js  | 6 ++----
 .../src/ReactFlightDOMServerBrowser.js                      | 6 ++----
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js b/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js
index b83e63236b30..530139715e84 100644
--- a/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js
+++ b/packages/react-dom/src/server/ReactDOMFizzServerBrowser.js
@@ -63,10 +63,8 @@ function renderToReadableStream(
             abort(request);
           },
         },
-        {
-          highWaterMark: 0,
-          size: () => 1,
-        },
+        // $FlowFixMe size() methods are not allowed on byte streams.
+        {highWaterMark: 0},
       ): any);
       // TODO: Move to sub-classing ReadableStream.
       stream.allReady = allReady;
diff --git a/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js b/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js
index 78f1e9ce84d7..a00eb8c44106 100644
--- a/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js
+++ b/packages/react-server-dom-webpack/src/ReactFlightDOMServerBrowser.js
@@ -44,10 +44,8 @@ function renderToReadableStream(
       },
       cancel(reason) {},
     },
-    {
-      highWaterMark: 0,
-      size: () => 1,
-    },
+    // $FlowFixMe size() methods are not allowed on byte streams.
+    {highWaterMark: 0},
   );
   return stream;
 }