fix: Crash in Client when reading integrations

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Fixes
+
+- Crash in Client when reading integrations (#2398)
+
 ## 7.31.1
 
 ### Fixes

Sources/Sentry/SentryClient.m

@@ -641,7 +641,13 @@ - (void)setSdk:(SentryEvent *)event
     id integrations = event.extra[@"__sentry_sdk_integrations"];
     if (!integrations) {
         integrations = [NSMutableArray new];
-        for (NSString *integration in SentrySDK.currentHub.installedIntegrationNames) {
+
+        // The SDK can send an event before it installs all integrations, which add to this list. To
+        // avoid an exception while iterating over a list while items get added to it, we copy it.
+        // With that approach, we might not have the complete integration list. To fix this, the SDK
+        // would need to ask all integrations first if they should be installed before actually
+        // installing them, which would be quite a bit a of a refactoring.
+        for (NSString *integration in SentrySDK.currentHub.installedIntegrationNames.copy) {
             // Every integration starts with "Sentry" and ends with "Integration". To keep the
             // payload of the event small we remove both.
             NSString *withoutSentry = [integration stringByReplacingOccurrencesOfString:@"Sentry"

Tests/SentryTests/SentryClientTests.swift

@@ -1264,6 +1264,29 @@ class SentryClientTest: XCTestCase {
         XCTAssertEqual(item, fixture.transportAdapter.sendEventWithTraceStateInvocations.first?.additionalEnvelopeItems.first)
     }
 
+    @available(iOS 13.0, tvOS 13.0, OSX 10.15, * )
+    func testConcurrentlyAddingInstalledIntegrations_WhileSendingEvents() async {
+        let sut = fixture.getSut()
+
+        let hub = SentryHub(client: sut, andScope: nil)
+        SentrySDK.setCurrentHub(hub)
+
+        // Run this in a loop to ensure that add while iterating over the integrations
+        // Running it once doesn't guaranty failure
+        for _ in 0..<100 {
+            let install = Task {
+                for i in 0..<10_000 {
+                    hub.installedIntegrationNames.add("Integration\(i)")
+                }
+            }
+
+            sut.capture(event: fixture.event)
+            install.cancel()
+            await install.value
+            hub.installedIntegrationNames.removeAllObjects()
+        }
+    }
+
     private func givenEventWithDebugMeta() -> Event {
         let event = Event(level: SentryLevel.fatal)
         let debugMeta = DebugMeta()