From 071c61d89b3c6662c2c8e771e265ee377119e844 Mon Sep 17 00:00:00 2001
From: Hashim1999164 <64767361+Hashim1999164@users.noreply.github.com>
Date: Wed, 19 Aug 2026 02:51:25 +0500
Subject: [PATCH] Ignore file watcher change events that omit a changes
 payload.

---
 .../metro/src/DeltaBundler/DeltaCalculator.js |  6 +++++-
 .../__tests__/DeltaCalculator-test.js         | 21 +++++++++++++++++++
 .../metro/src/node-haste/DependencyGraph.js   |  6 +++++-
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/packages/metro/src/DeltaBundler/DeltaCalculator.js b/packages/metro/src/DeltaBundler/DeltaCalculator.js
index 3088cae280..86dd81b806 100644
--- a/packages/metro/src/DeltaBundler/DeltaCalculator.js
+++ b/packages/metro/src/DeltaBundler/DeltaCalculator.js
@@ -199,7 +199,11 @@ export default class DeltaCalculator<T> extends EventEmitter {
     return false;
   }
 
-  _handleMultipleFileChanges = (changeEvent: ChangeEvent) => {
+  _handleMultipleFileChanges = (changeEvent: ?ChangeEvent) => {
+    // Some third party watchers emit a bare 'change' with no payload.
+    if (changeEvent == null || changeEvent.changes == null) {
+      return;
+    }
     const {changes, logger, rootDir} = changeEvent;
 
     // Process added files: deleted+added = modified, otherwise added
diff --git a/packages/metro/src/DeltaBundler/__tests__/DeltaCalculator-test.js b/packages/metro/src/DeltaBundler/__tests__/DeltaCalculator-test.js
index 917c05f956..05d45aeaa1 100644
--- a/packages/metro/src/DeltaBundler/__tests__/DeltaCalculator-test.js
+++ b/packages/metro/src/DeltaBundler/__tests__/DeltaCalculator-test.js
@@ -420,6 +420,27 @@ describe.each(['posix', 'win32'])('DeltaCalculator (%s)', osPlatform => {
     });
   });
 
+  test('should ignore change events that omit the changes payload', async () => {
+    await deltaCalculator.getDelta({reset: false, shallow: false});
+
+    expect(() => {
+      fileWatcher.emit('change');
+      fileWatcher.emit('change', {});
+    }).not.toThrow();
+
+    const result = await deltaCalculator.getDelta({
+      reset: false,
+      shallow: false,
+    });
+
+    expect(result).toEqual({
+      added: new Map(),
+      modified: new Map(),
+      deleted: new Set(),
+      reset: false,
+    });
+  });
+
   test('should emit an event when there is a relevant file change', done => {
     deltaCalculator
       .getDelta({reset: false, shallow: false})
diff --git a/packages/metro/src/node-haste/DependencyGraph.js b/packages/metro/src/node-haste/DependencyGraph.js
index d645af4aad..ae58113d4e 100644
--- a/packages/metro/src/node-haste/DependencyGraph.js
+++ b/packages/metro/src/node-haste/DependencyGraph.js
@@ -151,7 +151,11 @@ export default class DependencyGraph extends EventEmitter {
     await this._initializedPromise;
   }
 
-  _onHasteChange({changes, rootDir}: ChangeEvent) {
+  _onHasteChange(changeEvent: ?ChangeEvent) {
+    if (changeEvent == null || changeEvent.changes == null) {
+      return;
+    }
+    const {changes, rootDir} = changeEvent;
     this._resolutionCache = new Map();
     [
       ...changes.addedFiles,