From 96d95a50fc40c1afd8b31800f63c6688484b6f93 Mon Sep 17 00:00:00 2001
From: Ada <dreamyvoid@gmail.com>
Date: Wed, 4 Feb 2026 15:24:14 -0800
Subject: [PATCH] fix: resolve ReadableStream in simulator so LangGraph runs on
 RN
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Add src/polyfills.ts as the first executed module; inject ReadableStream/WritableStream/TransformStream via web-streams-polyfill and ponyfill fallback
- Import polyfills at the top of App.tsx so globals are set before any LangChain/LangGraph code loads
- Add assets/images/icon.png to fix Metro “Asset not found” for icon
---
 App.tsx                |   1 +
 assets/images/icon.png | Bin 0 -> 70 bytes
 src/polyfills.ts       |  15 +++++++++++++++
 3 files changed, 16 insertions(+)
 create mode 100644 assets/images/icon.png
 create mode 100644 src/polyfills.ts

diff --git a/App.tsx b/App.tsx
index cecce47..c17ecbc 100644
--- a/App.tsx
+++ b/App.tsx
@@ -4,6 +4,7 @@
  * Main application component with authentication routing.
  * Shows loading screen while restoring auth state.
  */
+import './src/polyfills';
 
 import React from 'react';
 import { Buffer } from 'buffer';
diff --git a/assets/images/icon.png b/assets/images/icon.png
new file mode 100644
index 0000000000000000000000000000000000000000..f37764b1f7606623616dcdc169cc858273ea2d94
GIT binary patch
literal 70
zcmeAS@N?(olHy`uVBq!ia0vp^j3CUx1|;Q0k92}1TpU9xZYBRYe;|OLfu)tPp=D){
QB2a?C)78&qol`;+0Lr!y6951J

literal 0
HcmV?d00001

diff --git a/src/polyfills.ts b/src/polyfills.ts
new file mode 100644
index 0000000..c9c8fde
--- /dev/null
+++ b/src/polyfills.ts
@@ -0,0 +1,15 @@
+/**
+ * Polyfills that must run before any other app code (including LangChain/LangGraph).
+ * This file is imported as the very first line in App.tsx so that ReadableStream
+ * exists before @langchain/core or @langchain/langgraph are loaded.
+ */
+import 'web-streams-polyfill';
+
+// Ensure globalThis has ReadableStream (main polyfill may not patch in RN/Metro)
+const g = typeof globalThis !== 'undefined' ? globalThis : (typeof global !== 'undefined' ? global : (typeof self !== 'undefined' ? self : {}));
+if (typeof (g as any).ReadableStream === 'undefined') {
+  const ponyfill = require('web-streams-polyfill/dist/ponyfill.js');
+  (g as any).ReadableStream = ponyfill.ReadableStream;
+  (g as any).WritableStream = ponyfill.WritableStream;
+  (g as any).TransformStream = ponyfill.TransformStream;
+}