From 8e8186ad188b2ba9af8eafd77c66b423c3512c8d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kry=C5=A1tof=20Wold=C5=99ich?=
 <31292499+krystofwoldrich@users.noreply.github.com>
Date: Mon, 26 Feb 2024 13:07:15 +0100
Subject: [PATCH] fix(symbolication): Ignore dev server JSON responses (#3611)

---
 CHANGELOG.md                             |  1 +
 src/js/integrations/debugsymbolicator.ts | 12 +++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a9d0b312fd..9696bf73be 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 ### Fixes
 
 - Option `enabled: false` ensures no events are sent ([#3606](https://github.com/getsentry/sentry-react-native/pull/3606))
+- Ignore JSON response when retrieving source context from local Expo Dev Server ([#3611](https://github.com/getsentry/sentry-react-native/pull/3611))
 
 ### Dependencies
 
diff --git a/src/js/integrations/debugsymbolicator.ts b/src/js/integrations/debugsymbolicator.ts
index 4ab109f4fe..1174c79053 100644
--- a/src/js/integrations/debugsymbolicator.ts
+++ b/src/js/integrations/debugsymbolicator.ts
@@ -219,7 +219,17 @@ export class DebugSymbolicator implements Integration {
           if (xhr.status !== 200) {
             resolve(null);
           }
-          resolve(xhr.responseText);
+          const response = xhr.responseText;
+          if (
+            typeof response !== 'string' ||
+            // Expo Dev Server responses with status 200 and config JSON
+            // when web support not enabled and requested file not found
+            response.startsWith('{')
+          ) {
+            resolve(null);
+          }
+
+          resolve(response);
         }
       };
       xhr.onerror = (): void => {