From 09e85a7c7b571411590707e497b4c56197abc94b Mon Sep 17 00:00:00 2001
From: Anna Kocheshkova <v-annkoc@microsoft.com>
Date: Fri, 7 Aug 2020 11:21:04 +0300
Subject: [PATCH] Fix sending logs from applicationWillTerminate

---
 .../Internals/Channel/MSChannelGroupDefault.m | 31 +++++++++++++++++
 .../Channel/MSChannelGroupDefaultPrivate.h    | 13 ++++++++
 .../MSChannelGroupDefaultTests.m              | 33 +++++++++++++++++++
 CHANGELOG.md                                  |  4 +++
 4 files changed, 81 insertions(+)

diff --git a/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefault.m b/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefault.m
index 1e381d46c3..be68974fdb 100644
--- a/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefault.m
+++ b/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefault.m
@@ -13,6 +13,12 @@
 
 @implementation MSChannelGroupDefault
 
+#if !TARGET_OS_OSX
+
+@synthesize delayedProcessingSemaphore = _delayedProcessingSemaphore;
+
+#endif
+
 #pragma mark - Initialization
 
 - (instancetype)initWithHttpClient:(id<MSHttpClientProtocol>)httpClient installId:(NSUUID *)installId logUrl:(NSString *)logUrl {
@@ -32,6 +38,9 @@ - (instancetype)initWithIngestion:(nullable MSAppCenterIngestion *)ingestion {
     if (ingestion) {
       _ingestion = ingestion;
     }
+#if !TARGET_OS_OSX
+    _delayedProcessingSemaphore = dispatch_semaphore_create(0);
+#endif
   }
   return self;
 }
@@ -177,6 +186,17 @@ - (void)channel:(id<MSChannelProtocol>)channel didResumeWithIdentifyingObject:(i
 
 - (void)setEnabled:(BOOL)isEnabled andDeleteDataOnDisabled:(BOOL)deleteData {
 
+#if !TARGET_OS_OSX
+  if (isEnabled) {
+    [MS_NOTIFICATION_CENTER addObserver:self
+                               selector:@selector(applicationWillTerminate:)
+                                   name:UIApplicationWillTerminateNotification
+                                 object:nil];
+  } else {
+    [MS_NOTIFICATION_CENTER removeObserver:self];
+  }
+#endif
+
   // Propagate to ingestion.
   [self.ingestion setEnabled:isEnabled andDeleteDataOnDisabled:deleteData];
 
@@ -199,6 +219,17 @@ - (void)setEnabled:(BOOL)isEnabled andDeleteDataOnDisabled:(BOOL)deleteData {
    */
 }
 
+#if !TARGET_OS_OSX
+- (void)applicationWillTerminate:(__unused UIApplication *)application {
+
+  // Block logs queue so that it isn't killed before app termination.
+  dispatch_async(self.logsDispatchQueue, ^{
+    dispatch_semaphore_signal(self.delayedProcessingSemaphore);
+  });
+  dispatch_semaphore_wait(self.delayedProcessingSemaphore, dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC));
+}
+#endif
+
 #pragma mark - Pause / Resume
 
 - (void)pauseWithIdentifyingObject:(id<NSObject>)identifyingObject {
diff --git a/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefaultPrivate.h b/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefaultPrivate.h
index befe90615b..f3c1547b4d 100644
--- a/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefaultPrivate.h
+++ b/AppCenter/AppCenter/Internals/Channel/MSChannelGroupDefaultPrivate.h
@@ -18,6 +18,19 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (instancetype)initWithIngestion:(nullable MSAppCenterIngestion *)ingestion;
 
+#if !TARGET_OS_OSX
+/**
+ * Semaphore for blocking logs queue on applicationWillTerminate.
+ */
+@property dispatch_semaphore_t delayedProcessingSemaphore;
+
+/**
+ * Called when applciation is terminating.
+ */
+- (void)applicationWillTerminate:(__unused UIApplication *)application;
+
+#endif
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/AppCenter/AppCenterTests/MSChannelGroupDefaultTests.m b/AppCenter/AppCenterTests/MSChannelGroupDefaultTests.m
index 2ebc787b03..8e7c709bc4 100644
--- a/AppCenter/AppCenterTests/MSChannelGroupDefaultTests.m
+++ b/AppCenter/AppCenterTests/MSChannelGroupDefaultTests.m
@@ -1,6 +1,11 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+#import "TargetConditionals.h"
+#if !TARGET_OS_OSX
+#import <UIKit/UIKit.h>
+#endif
+
 #import "MSAbstractLogInternal.h"
 #import "MSAppCenterIngestion.h"
 #import "MSChannelDelegate.h"
@@ -61,6 +66,34 @@ - (void)tearDown {
   [super tearDown];
 }
 
+#if !TARGET_OS_OSX
+- (void)testAppIsKilled {
+
+  // If
+  [self.sut setEnabled:YES andDeleteDataOnDisabled:YES];
+  id sut = OCMPartialMock(self.sut);
+
+  // When
+  [[NSNotificationCenter defaultCenter] postNotificationName:UIApplicationWillTerminateNotification object:sut];
+
+  // Then
+  OCMVerify([sut applicationWillTerminate:OCMOCK_ANY]);
+  XCTAssertNotNil(self.sut.logsDispatchQueue);
+  
+  // If
+  [self.sut setEnabled:NO andDeleteDataOnDisabled:YES];
+  OCMReject([sut applicationWillTerminate:OCMOCK_ANY]);
+  
+  // When
+  [[NSNotificationCenter defaultCenter] postNotificationName:UIApplicationWillTerminateNotification object:sut];
+  
+  // Then
+  self.sut.logsDispatchQueue = nil;
+  OCMVerifyAll(sut);
+  [sut stopMocking];
+}
+#endif
+
 #pragma mark - Tests
 
 - (void)testNewInstanceWasInitialisedCorrectly {
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1ea91d3b3b..0455282854 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@
 
 * **[Fix]** Fix compatibility with Xcode 12 beta when integrating SDK from sources.
 
+### App Center Analytics
+
+* **[Fix]** Fix sending logs from `applicationWillTerminate`.
+
 ___
 
 ## Version 3.3.2