From fd89f83db8434e026384a977f19ce0cbc3130d32 Mon Sep 17 00:00:00 2001
From: Sebastian Markbage <sema@fb.com>
Date: Mon, 26 Apr 2021 21:56:42 -0400
Subject: [PATCH] Swap the primary renderer flag in the legacy stream config

This allows the legacy implementation to co-exist with the new
implementation.

But primarily it allows Fiber and the legacy renderToString to co-exist.
---
 .../react-dom/src/server/ReactDOMLegacyServerStreamConfig.js   | 2 ++
 packages/react-dom/src/server/ReactDOMServerFormatConfig.js    | 3 ++-
 packages/react-server/src/ReactServerStreamConfigBrowser.js    | 2 ++
 packages/react-server/src/ReactServerStreamConfigNode.js       | 2 ++
 4 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/packages/react-dom/src/server/ReactDOMLegacyServerStreamConfig.js b/packages/react-dom/src/server/ReactDOMLegacyServerStreamConfig.js
index 4cfe16091bc58..c1d6c1df07ef9 100644
--- a/packages/react-dom/src/server/ReactDOMLegacyServerStreamConfig.js
+++ b/packages/react-dom/src/server/ReactDOMLegacyServerStreamConfig.js
@@ -16,6 +16,8 @@ export type Destination = {
 export type PrecomputedChunk = string;
 export type Chunk = string;
 
+export const isPrimaryStreamConfig = false;
+
 export function scheduleWork(callback: () => void) {
   callback();
 }
diff --git a/packages/react-dom/src/server/ReactDOMServerFormatConfig.js b/packages/react-dom/src/server/ReactDOMServerFormatConfig.js
index 72e984f12824b..3e77b7ce35a8e 100644
--- a/packages/react-dom/src/server/ReactDOMServerFormatConfig.js
+++ b/packages/react-dom/src/server/ReactDOMServerFormatConfig.js
@@ -23,6 +23,7 @@ import {
   writeChunk,
   stringToChunk,
   stringToPrecomputedChunk,
+  isPrimaryStreamConfig,
 } from 'react-server/src/ReactServerStreamConfig';
 
 import {
@@ -50,7 +51,7 @@ import isArray from 'shared/isArray';
 
 // Used to distinguish these contexts from ones used in other renderers.
 // E.g. this can be used to distinguish legacy renderers from this modern one.
-export const isPrimaryRenderer = true;
+export const isPrimaryRenderer = isPrimaryStreamConfig;
 
 // Per response, global state that is not contextual to the rendering subtree.
 export type ResponseState = {
diff --git a/packages/react-server/src/ReactServerStreamConfigBrowser.js b/packages/react-server/src/ReactServerStreamConfigBrowser.js
index 3714be4302765..b669002aff771 100644
--- a/packages/react-server/src/ReactServerStreamConfigBrowser.js
+++ b/packages/react-server/src/ReactServerStreamConfigBrowser.js
@@ -12,6 +12,8 @@ export type Destination = ReadableStreamController;
 export type PrecomputedChunk = Uint8Array;
 export type Chunk = Uint8Array;
 
+export const isPrimaryStreamConfig = true;
+
 export function scheduleWork(callback: () => void) {
   callback();
 }
diff --git a/packages/react-server/src/ReactServerStreamConfigNode.js b/packages/react-server/src/ReactServerStreamConfigNode.js
index 4329554b7f050..c44d5b8ee6566 100644
--- a/packages/react-server/src/ReactServerStreamConfigNode.js
+++ b/packages/react-server/src/ReactServerStreamConfigNode.js
@@ -21,6 +21,8 @@ export type Destination = Writable & MightBeFlushable;
 export type PrecomputedChunk = Uint8Array;
 export type Chunk = string;
 
+export const isPrimaryStreamConfig = true;
+
 export function scheduleWork(callback: () => void) {
   setImmediate(callback);
 }