[PLAT-7702] Fix currentAppState when called before UIApplicationMain

Bugsnag.xcodeproj/project.pbxproj

@@ -659,6 +659,8 @@
 		01847DAD26441A5E00ADA4C7 /* BSGInternalErrorReporterTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 01847DAB26441A5E00ADA4C7 /* BSGInternalErrorReporterTests.m */; };
 		01847DAE26441A5E00ADA4C7 /* BSGInternalErrorReporterTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 01847DAB26441A5E00ADA4C7 /* BSGInternalErrorReporterTests.m */; };
 		0187D464255BD7B800C503D9 /* BugsnagApiClientTest.m in Sources */ = {isa = PBXBuildFile; fileRef = CB9103632502320A00E9D1E2 /* BugsnagApiClientTest.m */; };
+		01935AE2275E68E9007498B3 /* UIApplicationStub.m in Sources */ = {isa = PBXBuildFile; fileRef = 01935AE1275E68E9007498B3 /* UIApplicationStub.m */; };
+		01935AE3275E68E9007498B3 /* UIApplicationStub.m in Sources */ = {isa = PBXBuildFile; fileRef = 01935AE1275E68E9007498B3 /* UIApplicationStub.m */; };
 		019480D42625F3EB00E833ED /* BSGAppKitTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 019480D32625F3EB00E833ED /* BSGAppKitTests.m */; };
 		01A2C542271EB9B400A27B23 /* BSG_Symbolicate.c in Sources */ = {isa = PBXBuildFile; fileRef = 01A2C540271EB9B300A27B23 /* BSG_Symbolicate.c */; };
 		01A2C543271EB9B400A27B23 /* BSG_Symbolicate.c in Sources */ = {isa = PBXBuildFile; fileRef = 01A2C540271EB9B300A27B23 /* BSG_Symbolicate.c */; };
@@ -1336,6 +1338,8 @@
 		01847D942644140F00ADA4C7 /* BSGInternalErrorReporter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = BSGInternalErrorReporter.h; sourceTree = "<group>"; };
 		01847D952644140F00ADA4C7 /* BSGInternalErrorReporter.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = BSGInternalErrorReporter.m; sourceTree = "<group>"; };
 		01847DAB26441A5E00ADA4C7 /* BSGInternalErrorReporterTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = BSGInternalErrorReporterTests.m; sourceTree = "<group>"; };
+		01935AE0275E68E9007498B3 /* UIApplicationStub.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = UIApplicationStub.h; sourceTree = "<group>"; };
+		01935AE1275E68E9007498B3 /* UIApplicationStub.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = UIApplicationStub.m; sourceTree = "<group>"; };
 		01937CF9257A7B4C00F2DE31 /* Bugsnag+Private.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "Bugsnag+Private.h"; sourceTree = "<group>"; };
 		01937D11257A814D00F2DE31 /* BugsnagMetadata+Private.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "BugsnagMetadata+Private.h"; sourceTree = "<group>"; };
 		01937D2E257A83A900F2DE31 /* BugsnagApp+Private.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "BugsnagApp+Private.h"; sourceTree = "<group>"; };
@@ -1795,6 +1799,8 @@
 				004E35392487B375007FBAE4 /* Tests-Bridging-Header.h */,
 				CBA22499251E429C00B87416 /* TestSupport.h */,
 				CBA2249A251E429C00B87416 /* TestSupport.m */,
+				01935AE0275E68E9007498B3 /* UIApplicationStub.h */,
+				01935AE1275E68E9007498B3 /* UIApplicationStub.m */,
 				013D9CCF26C5262F0077F0AD /* UISceneStub.h */,
 				013D9CD026C5262F0077F0AD /* UISceneStub.m */,
 				01E8765C256684E700F4B70A /* URLSessionMock.h */,
@@ -2780,6 +2786,7 @@
 				008967782486D43700DC48C2 /* BSG_KSMachHeadersTests.m in Sources */,
 				0089673F2486D43700DC48C2 /* BugsnagAppTest.m in Sources */,
 				0089675A2486D43700DC48C2 /* BugsnagEnabledBreadcrumbTest.m in Sources */,
+				01935AE2275E68E9007498B3 /* UIApplicationStub.m in Sources */,
 				008967422486D43700DC48C2 /* BugsnagSessionTrackerStopTest.m in Sources */,
 				E701FAAF2490EFE8008D842F /* ConfigurationApiValidationTest.m in Sources */,
 				008967452486D43700DC48C2 /* BugsnagTests.m in Sources */,
@@ -3138,6 +3145,7 @@
 				01847DAE26441A5E00ADA4C7 /* BSGInternalErrorReporterTests.m in Sources */,
 				004E35372487AFF2007FBAE4 /* BugsnagHandledStateTest.m in Sources */,
 				016875C8258D003200DFFF69 /* NSUserDefaultsStub.m in Sources */,
+				01935AE3275E68E9007498B3 /* UIApplicationStub.m in Sources */,
 				01C17AE92542ED7F00C102C9 /* KSCrashReportWriterTests.m in Sources */,
 				00896A422486DBDD00DC48C2 /* BSGConfigurationBuilderTests.m in Sources */,
 				008967682486D43700DC48C2 /* BugsnagNotifierTest.m in Sources */,

Bugsnag/KSCrash/Source/KSCrash/Recording/BSG_KSSystemInfo.m

@@ -453,31 +453,40 @@ + (BOOL)isRunningInAppExtension {
 }
 
 #if BSG_PLATFORM_IOS || BSG_PLATFORM_TVOS
+
 + (UIApplicationState)currentAppState {
     // Only checked outside of app extensions since sharedApplication is
     // unavailable to extension UIKit APIs
     if ([self isRunningInAppExtension]) {
         return UIApplicationStateActive;
     }
 
-    UIApplicationState(^getState)(void) = ^() {
+    UIApplication * (^ getSharedApplication)(void) = ^() {
         // Calling this API indirectly to avoid a compile-time check that
         // [UIApplication sharedApplication] is not called from app extensions
         // (which is handled above)
-        UIApplication *app = [UIAPPLICATION performSelector:@selector(sharedApplication)];
-        return [app applicationState];
+        return [UIAPPLICATION performSelector:@selector(sharedApplication)];
     };
 
+    __block UIApplication *application = nil;
     if ([[NSThread currentThread] isMainThread]) {
-        return getState();
+        application = getSharedApplication();
     } else {
         // [UIApplication sharedApplication] is a main thread-only API
-        __block UIApplicationState state;
         dispatch_sync(dispatch_get_main_queue(), ^{
-            state = getState();
+            application = getSharedApplication();
         });
-        return state;
     }
+
+    // There will be no UIApplication if UIApplicationMain() has not yet been
+    // called. This happens if started from a SwiftUI app's init() function or
+    // UIKit app's main() function. Returning UIApplicationStateActive (0) would
+    // be higly misleading, so we must check for this condition.
+    if (!application) {
+        return UIApplicationStateBackground;
+    }
+
+    return application.applicationState;
 }
 
 + (BOOL)isInForeground:(UIApplicationState)state {
@@ -494,6 +503,7 @@ + (BOOL)isInForeground:(UIApplicationState)state {
     return state == UIApplicationStateInactive
         || state == UIApplicationStateActive;
 }
+
 #endif
 
 @end

CHANGELOG.md

@@ -1,6 +1,14 @@
 Changelog
 =========
 
+## TBD
+
+### Bug fixes
+
+* Fix `UIApplicationState` detection when started from a SwiftUI app's `init()` function.
+  This fixes false positive OOMs on iOS 15 for apps that have been prewarmed without transitioning to the foreground.
+  [#1248](https://github.com/bugsnag/bugsnag-cocoa/pull/1248)
+
 ## 6.15.0 (2021-12-01)
 
 ### Enhancements

Tests/BugsnagTests/BugsnagConfigurationTests.m

@@ -103,6 +103,7 @@ - (void)testAddOnSessionBlock {
     // Call onSession blocks
     BugsnagClient *client = [[BugsnagClient alloc] initWithConfiguration:config];
     [client start];
+    [client resumeSession];
     [self waitForExpectationsWithTimeout:5.0 handler:nil];
 }
 
@@ -183,6 +184,7 @@ - (void)testAddOnSessionBlockThenRemove {
     // Call onSession blocks
     BugsnagClient *client = [[BugsnagClient alloc] initWithConfiguration:config];
     [client start];
+    [client resumeSession];
     [self waitForExpectations:@[expectation1] timeout:1.0];
 
     // Check it's called on new session start

Tests/BugsnagTests/UIApplicationStub.h

@@ -0,0 +1,26 @@
+//
+//  UIApplicationStub.h
+//  Bugsnag
+//
+//  Created by Nick Dowell on 06/12/2021.
+//  Copyright © 2021 Bugsnag Inc. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+#import <XCTest/XCTest.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface UIApplicationStub : NSObject
+
+@property (nonatomic) UIApplicationState applicationState;
+
+@end
+
+@interface XCTestCase (UIApplicationStub)
+
+- (void)setUpUIApplicationStub;
+
+@end
+
+NS_ASSUME_NONNULL_END

Tests/BugsnagTests/UIApplicationStub.m

@@ -0,0 +1,38 @@
+//
+//  UIApplicationStub.m
+//  Bugsnag
+//
+//  Created by Nick Dowell on 06/12/2021.
+//  Copyright © 2021 Bugsnag Inc. All rights reserved.
+//
+
+#import "UIApplicationStub.h"
+
+#import <objc/runtime.h>
+
+
+@implementation UIApplicationStub
+
+- (BOOL)isKindOfClass:(Class)aClass {
+    return aClass == [UIApplication class] || [super isKindOfClass:aClass];
+}
+
+@end
+
+
+@implementation XCTestCase (UIApplicationStub)
+
+- (void)setUpUIApplicationStub {
+    Method method = class_getClassMethod([UIApplication class], @selector(sharedApplication));
+    NSParameterAssert(method != NULL);
+
+    void *originalImplementation = method_setImplementation(method, imp_implementationWithBlock(^(){
+        return [[UIApplicationStub alloc] init];
+    }));
+
+    [self addTeardownBlock:^{
+        method_setImplementation(method, originalImplementation);
+    }];
+}
+
+@end

Tests/KSCrashTests/KSCrashState_Tests.m

@@ -30,13 +30,28 @@
 #import "BSG_KSCrashState.h"
 #import "BSG_KSCrashC.h"
 
+#if TARGET_OS_TV
+#import "UIApplicationStub.h"
+#endif
+
 
 @interface bsg_kscrashstate_Tests : FileBasedTestCase
 @end
 
 
 @implementation bsg_kscrashstate_Tests
 
+#if TARGET_OS_TV // Not needed on iOS because there the tests are injected into a host app
+
+- (void)setUp
+{
+    [self setUpUIApplicationStub]; // These tests assume applicationState == .active
+
+    [super setUp];
+}
+
+#endif
+
 - (void) testInitRelaunch
 {
     BSG_KSCrash_State context = {0};

Tests/KSCrashTests/KSSystemInfo_Tests.m

@@ -31,6 +31,10 @@
 #import "BSG_KSSystemInfo.h"
 #import "BSG_KSSystemInfoC.h"
 
+#if TARGET_OS_TV
+#import "UIApplicationStub.h"
+#endif
+
 
 @interface KSSystemInfo_Tests : XCTestCase @end
 
@@ -61,7 +65,9 @@ - (void) testCopyProcessName
 
 #if BSG_PLATFORM_TVOS || BSG_PLATFORM_IOS
 - (void)testCurrentAppState {
-    // Should default to active as tests aren't in an app bundle
+#if TARGET_OS_TV
+    [self setUpUIApplicationStub];
+#endif
     XCTAssertEqual(UIApplicationStateActive, [BSG_KSSystemInfo currentAppState]);
 }