From 1401ae27db68241507726fd1305f83fe5686b4c2 Mon Sep 17 00:00:00 2001
From: Alexander Pantiukhov <alex@apantiukhov.com>
Date: Thu, 6 Nov 2025 17:36:51 +0100
Subject: [PATCH 1/3] Fix how bundle IDs are getting defined for individual
 bundles

---
 .../core/src/js/tools/sentryMetroSerializer.ts   | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/packages/core/src/js/tools/sentryMetroSerializer.ts b/packages/core/src/js/tools/sentryMetroSerializer.ts
index 8e31f512b9..7e17dc1527 100644
--- a/packages/core/src/js/tools/sentryMetroSerializer.ts
+++ b/packages/core/src/js/tools/sentryMetroSerializer.ts
@@ -74,11 +74,19 @@ export const createSentryMetroSerializer = (customSerializer?: MetroSerializer):
     const { code: bundleCode, map: bundleMapString } = await extractSerializerResult(serializerResult);
 
     // Add debug id comment to the bundle
-    const debugId = determineDebugIdFromBundleSource(bundleCode);
+    let debugId = determineDebugIdFromBundleSource(bundleCode);
     if (!debugId) {
-      throw new Error(
-        'Debug ID was not found in the bundle. Call `options.sentryBundleCallback` if you are using a custom serializer.',
-      );
+      // For lazy-loaded chunks or bundles without the debug ID module,
+      // calculate the debug ID from the bundle content.
+      // This ensures Metro 0.83.2+ code-split bundles get debug IDs.
+      // That needs to be done because when Metro 0.83.2 stopped importing `BabelSourceMapSegment`
+      // from `@babel/generator` and defined it locally, it subtly changed the source map output format.
+      // https://github.com/facebook/metro/blob/main/packages/metro-source-map/src/source-map.js#L47
+      const hash = crypto.createHash('md5');
+      hash.update(bundleCode);
+      debugId = stringToUUID(hash.digest('hex'));
+      // eslint-disable-next-line no-console
+      console.log('info ' + `Bundle Debug ID (calculated): ${debugId}`);
     }
     // Only print debug id for command line builds => not hot reload from dev server
     // eslint-disable-next-line no-console

From ef6c42ef159c8a2e49bd882f19b40baf747dac51 Mon Sep 17 00:00:00 2001
From: Alexander Pantiukhov <alex@apantiukhov.com>
Date: Fri, 7 Nov 2025 09:47:37 +0100
Subject: [PATCH 2/3] Changelog update

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8e4e0ca67..78a2467936 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@
 ### Fixes
 
 - Android SDK not being disabled when `options.enabled` is set to `false`  ([#5334](https://github.com/getsentry/sentry-react-native/pull/5334))
+- Fixes how bundle IDs are getting defined for individual bundles ([#5342](https://github.com/getsentry/sentry-react-native/pull/5342))
 
 ### Dependencies
 

From 31ee206bf06e290ce88a7c69c9237082411ace1a Mon Sep 17 00:00:00 2001
From: Alexander Pantiukhov <alex@apantiukhov.com>
Date: Mon, 10 Nov 2025 15:52:34 +0100
Subject: [PATCH 3/3] Added test

---
 .../test/tools/sentryMetroSerializer.test.ts  | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/packages/core/test/tools/sentryMetroSerializer.test.ts b/packages/core/test/tools/sentryMetroSerializer.test.ts
index e654d59490..071ff2cd46 100644
--- a/packages/core/test/tools/sentryMetroSerializer.test.ts
+++ b/packages/core/test/tools/sentryMetroSerializer.test.ts
@@ -65,6 +65,49 @@ describe('Sentry Metro Serializer', () => {
       expect(debugId).toMatch(/^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$/);
     }
   });
+
+  test('calculates debug id from bundle code when debug id module is not found', async () => {
+    // Create a custom serializer that returns bundle code without the debug ID module
+    const customSerializer: MetroSerializer = async () => {
+      const bundleCodeWithoutDebugId = 'console.log("test bundle");';
+      return {
+        code: bundleCodeWithoutDebugId,
+        map: '{"version":3,"sources":[],"names":[],"mappings":""}',
+      };
+    };
+
+    const serializer = createSentryMetroSerializer(customSerializer);
+    const bundle = await serializer(...mockMinSerializerArgs());
+
+    if (typeof bundle === 'string') {
+      fail('Expected bundle to be an object with a "code" property');
+    }
+
+    // The debug ID should be calculated from the bundle code content
+    // and added as a comment in the bundle code
+    expect(bundle.code).toContain('//# debugId=');
+
+    // Extract the debug ID from the comment
+    const debugIdMatch = bundle.code.match(/\/\/# debugId=([0-9a-fA-F-]+)/);
+    expect(debugIdMatch).toBeTruthy();
+    const debugId = debugIdMatch?.[1];
+
+    // Verify it's a valid UUID format
+    expect(debugId).toMatch(/^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$/);
+
+    // Verify the debug ID is also in the source map
+    const sourceMap = JSON.parse(bundle.map);
+    expect(sourceMap.debug_id).toBe(debugId);
+    expect(sourceMap.debugId).toBe(debugId);
+
+    // The calculated debug ID should be deterministic based on the bundle content
+    // Running the serializer again with the same content should produce the same debug ID
+    const bundle2 = await serializer(...mockMinSerializerArgs());
+    if (typeof bundle2 !== 'string') {
+      const debugIdMatch2 = bundle2.code.match(/\/\/# debugId=([0-9a-fA-F-]+)/);
+      expect(debugIdMatch2?.[1]).toBe(debugId);
+    }
+  });
 });
 
 function mockMinSerializerArgs(options?: {