feat: track network connectivity changes with breadcrumbs

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Features
+
+- Record changes to network connectivity in breadcrumbs (#3232)
+
 ## 8.10.0
 
 ### Features

Sources/Sentry/SentryBreadcrumbTracker.m

@@ -3,8 +3,10 @@
 #import "SentryBreadcrumbDelegate.h"
 #import "SentryClient.h"
 #import "SentryDefines.h"
+#import "SentryDependencyContainer.h"
 #import "SentryHub.h"
 #import "SentryLog.h"
+#import "SentryReachability.h"
 #import "SentrySDK+Private.h"
 #import "SentryScope.h"
 #import "SentrySwift.h"
@@ -45,6 +47,7 @@
     _delegate = delegate;
     [self addEnabledCrumb];
     [self trackApplicationUIKitNotifications];
+    [self trackNetworkConnectivityChanges];
 }
 
 - (void)startSwizzle
@@ -120,6 +123,20 @@
 #endif
 }
 
+- (void)trackNetworkConnectivityChanges
+{
+    [SentryDependencyContainer.sharedInstance.reachability
+           monitorURL:[NSURL URLWithString:@"https://sentry.io"]
+        usingCallback:^(BOOL connected, NSString *_Nonnull typeDescription) {
+            SentryBreadcrumb *crumb =
+                [[SentryBreadcrumb alloc] initWithLevel:kSentryLevelInfo
+                                               category:@"device.connectivity"];
+            crumb.type = @"connectivity";
+            crumb.data = [NSDictionary dictionaryWithObject:typeDescription forKey:@"connectivity"];
+            [self.delegate addBreadcrumb:crumb];
+        }];
+}
+
 - (void)addBreadcrumbWithType:(NSString *)type
                  withCategory:(NSString *)category
                     withLevel:(SentryLevel)level

Sources/Sentry/SentryDependencyContainer.m

@@ -27,6 +27,10 @@
 #    import "SentryFramesTracker.h"
 #endif // SENTRY_HAS_UIKIT
 
+#if !TARGET_OS_WATCH
+#    import "SentryReachability.h"
+#endif // !TARGET_OS_WATCH
+
 @implementation SentryDependencyContainer
 
 static SentryDependencyContainer *instance;
@@ -311,4 +315,18 @@ - (SentryMXManager *)metricKitManager
 
 #endif // SENTRY_HAS_METRIC_KIT
 
+#if !TARGET_OS_WATCH
+- (SentryReachability *)reachability
+{
+    if (_reachability == nil) {
+        @synchronized(sentryDependencyContainerLock) {
+            if (_reachability == nil) {
+                _reachability = [[SentryReachability alloc] init];
+            }
+        }
+    }
+    return _reachability;
+}
+#endif // !TARGET_OS_WATCH
+
 @end

Sources/Sentry/SentryReachability.m

@@ -36,9 +36,9 @@
 static SCNetworkReachabilityFlags sentry_current_reachability_state
     = kSCNetworkReachabilityFlagsUninitialized;
 
-static NSString *const SentryConnectivityCellular = @"cellular";
-static NSString *const SentryConnectivityWiFi = @"wifi";
-static NSString *const SentryConnectivityNone = @"none";
+NSString *const SentryConnectivityCellular = @"cellular";
+NSString *const SentryConnectivityWiFi = @"wifi";
+NSString *const SentryConnectivityNone = @"none";
 
 /**
  * Check whether the connectivity change should be noted or ignored.

Sources/Sentry/include/HybridPublic/SentryDependencyContainer.h

@@ -25,7 +25,11 @@
 @class SentryScreenshot;
 @class SentryUIApplication;
 @class SentryViewHierarchy;
-#endif
+#endif // SENTRY_HAS_UIKIT
+
+#if !TARGET_OS_WATCH
+@class SentryReachability;
+#endif // !TARGET_OS_WATCH
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -62,6 +66,10 @@ SENTRY_NO_INIT
 @property (nonatomic, strong) SentryUIApplication *application;
 #endif
 
+#if !TARGET_OS_WATCH
+@property (nonatomic, strong) SentryReachability *reachability;
+#endif // !TARGET_OS_WATCH
+
 - (SentryANRTracker *)getANRTracker:(NSTimeInterval)timeout;
 
 #if SENTRY_HAS_METRIC_KIT

Sources/Sentry/include/SentryReachability.h

@@ -24,6 +24,7 @@
 // THE SOFTWARE.
 //
 
+#import "SentryDefines.h"
 #import <Foundation/Foundation.h>
 
 #if !TARGET_OS_WATCH
@@ -38,6 +39,10 @@ NSString *SentryConnectivityFlagRepresentation(SCNetworkReachabilityFlags flags)
 
 BOOL SentryConnectivityShouldReportChange(SCNetworkReachabilityFlags flags);
 
+SENTRY_EXTERN NSString *const SentryConnectivityCellular;
+SENTRY_EXTERN NSString *const SentryConnectivityWiFi;
+SENTRY_EXTERN NSString *const SentryConnectivityNone;
+
 /**
  * Function signature to connectivity monitoring callback of @c SentryReachability
  * @param connected @c YES if the monitored URL is reachable

Tests/SentryTests/Integrations/Breadcrumbs/SentryBreadcrumbTrackerTests.swift

@@ -30,6 +30,31 @@ class SentryBreadcrumbTrackerTests: XCTestCase {
         XCTAssertEqual(0, dict?.count)
     }
 
+    func testNetworkConnectivityChangeBreadcrumbs() throws {
+        let testReachability = TestSentryReachability()
+        SentryDependencyContainer.sharedInstance().reachability = testReachability
+        let sut = SentryBreadcrumbTracker(swizzleWrapper: SentrySwizzleWrapper.sharedInstance)
+        sut.start(with: delegate)
+        let states = [SentryConnectivityCellular,
+        SentryConnectivityWiFi,
+        SentryConnectivityNone,
+        SentryConnectivityWiFi,
+        SentryConnectivityCellular,
+        SentryConnectivityWiFi
+        ]
+        states.forEach {
+            testReachability.setReachabilityState(state: $0)
+        }
+        sut.stop()
+        XCTAssertEqual(delegate.addCrumbInvocations.count, states.count + 1) // 1 breadcrumb for the tracker start
+        try states.enumerated().forEach {
+            let crumb = delegate.addCrumbInvocations.invocations[$0.offset + 1]
+            XCTAssertEqual(crumb.type, "connectivity")
+            XCTAssertEqual(crumb.category, "device.connectivity")
+            XCTAssertEqual(try XCTUnwrap(crumb.data?["connectivity"] as? String), $0.element)
+        }
+    }
+
     func testSwizzlingStarted_ViewControllerAppears_AddsUILifeCycleBreadcrumb() {
         let scope = Scope()
         let client = TestClient(options: Options())

Tests/SentryTests/Networking/SentryReachabilityTests.m

@@ -20,20 +20,20 @@ - (void)tearDown
 
 - (void)testConnectivityRepresentations
 {
-    XCTAssertEqualObjects(@"none", SentryConnectivityFlagRepresentation(0));
-    XCTAssertEqualObjects(
-        @"none", SentryConnectivityFlagRepresentation(kSCNetworkReachabilityFlagsIsDirect));
+    XCTAssertEqualObjects(SentryConnectivityNone, SentryConnectivityFlagRepresentation(0));
+    XCTAssertEqualObjects(SentryConnectivityNone,
+        SentryConnectivityFlagRepresentation(kSCNetworkReachabilityFlagsIsDirect));
 #    if SENTRY_HAS_UIKIT
     // kSCNetworkReachabilityFlagsIsWWAN does not exist on macOS
-    XCTAssertEqualObjects(
-        @"none", SentryConnectivityFlagRepresentation(kSCNetworkReachabilityFlagsIsWWAN));
-    XCTAssertEqualObjects(@"cellular",
+    XCTAssertEqualObjects(SentryConnectivityNone,
+        SentryConnectivityFlagRepresentation(kSCNetworkReachabilityFlagsIsWWAN));
+    XCTAssertEqualObjects(SentryConnectivityCellular,
         SentryConnectivityFlagRepresentation(
             kSCNetworkReachabilityFlagsIsWWAN | kSCNetworkReachabilityFlagsReachable));
 #    endif // SENTRY_HAS_UIKIT
-    XCTAssertEqualObjects(
-        @"wifi", SentryConnectivityFlagRepresentation(kSCNetworkReachabilityFlagsReachable));
-    XCTAssertEqualObjects(@"wifi",
+    XCTAssertEqualObjects(SentryConnectivityWiFi,
+        SentryConnectivityFlagRepresentation(kSCNetworkReachabilityFlagsReachable));
+    XCTAssertEqualObjects(SentryConnectivityWiFi,
         SentryConnectivityFlagRepresentation(
             kSCNetworkReachabilityFlagsReachable | kSCNetworkReachabilityFlagsIsDirect));
 }

Tests/SentryTests/Networking/TestSentryReachability.swift

@@ -9,8 +9,12 @@
         self.block = block
     }
 
+    func setReachabilityState(state: String) {
+        block?(state != SentryConnectivityNone, state)
+    }
+
     func triggerNetworkReachable() {
-        block?(true, "wifi")
+        block?(true, SentryConnectivityWiFi)
     }
 
     var stopMonitoringInvocations = Invocations<Void>()