From 60f0499e7e4bde213294458ea8b9fa3e3a04c170 Mon Sep 17 00:00:00 2001
From: Luca Forstner <luca.forstner@sentry.io>
Date: Thu, 3 Oct 2024 22:08:48 +0000
Subject: [PATCH] fix(browser): Ensure `wrap()` only returns functions (#13838)

---
 packages/browser/src/helpers.ts                     |  8 +++++++-
 .../browser/test/unit/integrations/helpers.test.ts  | 13 +++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/packages/browser/src/helpers.ts b/packages/browser/src/helpers.ts
index 35930167672d..da707cb4e437 100644
--- a/packages/browser/src/helpers.ts
+++ b/packages/browser/src/helpers.ts
@@ -66,7 +66,13 @@ export function wrap(
     // the original wrapper.
     const wrapper = fn.__sentry_wrapped__;
     if (wrapper) {
-      return wrapper;
+      if (typeof wrapper === 'function') {
+        return wrapper;
+      } else {
+        // If we find that the `__sentry_wrapped__` function is not a function at the time of accessing it, it means
+        // that something messed with it. In that case we want to return the originally passed function.
+        return fn;
+      }
     }
 
     // We don't wanna wrap it twice
diff --git a/packages/browser/test/unit/integrations/helpers.test.ts b/packages/browser/test/unit/integrations/helpers.test.ts
index 34420a6d30bc..8311e10ba41f 100644
--- a/packages/browser/test/unit/integrations/helpers.test.ts
+++ b/packages/browser/test/unit/integrations/helpers.test.ts
@@ -174,4 +174,17 @@ describe('internal wrap()', () => {
     expect(wrapped.__sentry_original__).toBe(fn);
     expect(fn.__sentry_wrapped__).toBe(wrapped);
   });
+
+  it('should only return __sentry_wrapped__ when it is a function', () => {
+    const fn = (() => 1337) as WrappedFunction;
+
+    wrap(fn);
+    expect(fn).toHaveProperty('__sentry_wrapped__');
+    fn.__sentry_wrapped__ = 'something that is not a function' as any;
+
+    const wrapped = wrap(fn);
+
+    expect(wrapped).toBe(fn);
+    expect(wrapped).not.toBe('something that is not a function');
+  });
 });