From 3b638714a052bd35a788f17c4a4b876151854fca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rub=C3=A9n=20Norte?= <rubennorte@meta.com>
Date: Fri, 13 Dec 2024 07:40:05 -0800
Subject: [PATCH] Lazy load Fabric renderer in Fantom (#48261)

Summary:

Changelog: [internal]

This avoids initializing the renderer if the caller doesn't invoke any of the methods that use it.

Differential Revision: D67199972
---
 packages/react-native-fantom/src/index.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/packages/react-native-fantom/src/index.js b/packages/react-native-fantom/src/index.js
index 0c3b79f7dbcd3b..fcd2bf1a3da0df 100644
--- a/packages/react-native-fantom/src/index.js
+++ b/packages/react-native-fantom/src/index.js
@@ -15,7 +15,6 @@ import type {
 import type {MixedElement} from 'react';
 
 import getFantomRenderedOutput from './getFantomRenderedOutput';
-import ReactFabric from 'react-native/Libraries/Renderer/shims/ReactFabric';
 
 let globalSurfaceIdCounter = 1;
 
@@ -23,6 +22,15 @@ const nativeRuntimeScheduler = global.nativeRuntimeScheduler;
 const schedulerPriorityImmediate =
   nativeRuntimeScheduler.unstable_ImmediatePriority;
 
+let ReactFabric = null;
+function getReactFabric() {
+  if (ReactFabric == null) {
+    ReactFabric =
+      require('react-native/Libraries/Renderer/shims/ReactFabric').default;
+  }
+  return ReactFabric;
+}
+
 class Root {
   #surfaceId: number;
   #hasRendered: boolean = false;
@@ -38,7 +46,7 @@ class Root {
       this.#hasRendered = true;
     }
 
-    ReactFabric.render(element, this.#surfaceId, () => {}, true);
+    getReactFabric().render(element, this.#surfaceId, () => {}, true);
   }
 
   getMountingLogs(): Array<string> {