[PLAT-4646] Implement discardClasses configuration option

Bugsnag/BugsnagErrorReportSink.m

@@ -95,6 +95,13 @@ - (void)sendStoredReports:(NSDictionary <NSString *, NSDictionary *> *)ksCrashRe
         NSDictionary *report = ksCrashReports[fileKey];
         BugsnagEvent *event = [[BugsnagEvent alloc] initWithKSReport:report];
         event.redactedKeys = configuration.redactedKeys;
+
+        NSString *errorClass = event.errors.firstObject.errorClass;
+        if ([configuration shouldDiscardErrorClass:errorClass]) {
+            bsg_log_info(@"Discarding event because errorClass \"%@\" matched configuration.discardClasses", errorClass);
+            [self finishActiveRequest:fileKey completed:YES error:nil block:block];
+            continue;
+        }
 
         if ([event shouldBeSent] && [self runOnSendBlocks:configuration event:event]) {
             storedEvents[fileKey] = event;

Bugsnag/Client/BugsnagClient.m

@@ -964,6 +964,12 @@ - (void)notify:(NSException *)exception
 - (void)notifyInternal:(BugsnagEvent *_Nonnull)event
                  block:(BugsnagOnErrorBlock)block
 {
+    NSString *errorClass = event.errors.firstObject.errorClass;
+    if ([self.configuration shouldDiscardErrorClass:errorClass]) {
+        bsg_log_info(@"Discarding event because errorClass \"%@\" matched configuration.discardClasses", errorClass);
+        return;
+    }
+
     // enhance device information with additional metadata
     NSDictionary *deviceFields = [self.state getMetadataFromSection:BSGKeyDeviceState];
 

Bugsnag/Configuration/BugsnagConfiguration+Private.h

@@ -49,6 +49,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)deletePersistedUserData;
 
+- (BOOL)shouldDiscardErrorClass:(NSString *)errorClass;
+
 - (BOOL)shouldRecordBreadcrumbType:(BSGBreadcrumbType)breadcrumbType;
 
 /// Throws an NSInvalidArgumentException if the API key is empty or missing.

Bugsnag/Configuration/BugsnagConfiguration.m

@@ -82,6 +82,7 @@ - (nonnull id)copyWithZone:(nullable NSZone *)zone {
     [copy setEnabledBreadcrumbTypes:self.enabledBreadcrumbTypes];
     [copy setEnabledErrorTypes:self.enabledErrorTypes];
     [copy setEnabledReleaseStages:self.enabledReleaseStages];
+    copy.discardClasses = self.discardClasses;
     [copy setRedactedKeys:self.redactedKeys];
     [copy setMaxBreadcrumbs:self.maxBreadcrumbs];
     copy->_metadata = [[BugsnagMetadata alloc] initWithDictionary:[[self.metadata toDictionary] mutableCopy]];
@@ -435,6 +436,21 @@ - (void)setMaxBreadcrumbs:(NSUInteger)maxBreadcrumbs {
     }
 }
 
+- (BOOL)shouldDiscardErrorClass:(NSString *)errorClass {
+    for (id obj in self.discardClasses) {
+        if ([obj isKindOfClass:[NSString class]]) {
+            if ([obj isEqualToString:errorClass]) {
+                return YES;
+            }
+        } else if ([obj isKindOfClass:[NSRegularExpression class]]) {
+            if ([obj firstMatchInString:errorClass options:0 range:NSMakeRange(0, errorClass.length)]) {
+                return YES;
+            }
+        }
+    }
+    return NO;
+}
+
 /**
  * Specific types of breadcrumb should be recorded if either enabledBreadcrumbTypes
  * is None, or contains the type.

Bugsnag/Payload/BugsnagEvent+Private.h

@@ -37,7 +37,7 @@ NS_ASSUME_NONNULL_BEGIN
 /// Property overrides.
 @property (readonly, copy) NSDictionary *overrides;
 
-@property NSSet<NSString *> *redactedKeys;
+@property NSSet<id> *redactedKeys;
 
 /// The release stage of the application
 @property (readwrite, copy, nullable) NSString *releaseStage;

Bugsnag/include/Bugsnag/BugsnagConfiguration.h

@@ -149,6 +149,20 @@ typedef BOOL (^BugsnagOnSessionBlock)(BugsnagSession *_Nonnull session);
  */
 @property(readwrite, retain, nullable) NSSet<id> *redactedKeys;
 
+/**
+ * A set of strings and / or NSRegularExpression objects that determine which errors should
+ * be discarded based on their `errorClass`.
+ *
+ * Comparisons are case sensitive.
+ *
+ * OnError / OnSendError blocks will not be called for discarded errors.
+ *
+ * Some examples of errorClass are: Objective-C exception names like "NSRangeException",
+ * signal names like "SIGABRT", mach exception names like "EXC_BREAKPOINT", and Swift
+ * error names like "Fatal error".
+ */
+@property(readwrite, copy, nullable) NSSet<id> *discardClasses;
+
 /**
  *  A general summary of what was occuring in the application
  */

CHANGELOG.md

@@ -1,6 +1,13 @@
 Changelog
 =========
 
+## TBD
+
+### Enhancements
+
+* Errors may now be discarded based on their `errorClass` using the new `discardClasses` configuration option.
+  [#938](https://github.com/bugsnag/bugsnag-cocoa/pull/938)
+
 ## 6.4.0 (2020-12-08)
 
 ### Enhancements

Tests/BugsnagConfigurationTests.m

@@ -850,4 +850,74 @@ - (void)testMetadataMutability {
     XCTAssertTrue([metadata2 isKindOfClass:[NSMutableDictionary class]]);
 }
 
+- (void)testDiscardClasses {
+    XCTAssertNil([[BugsnagConfiguration alloc] initWithApiKey:DUMMY_APIKEY_32CHAR_1].discardClasses, @"discardClasses should be nil be default");
+
+    NSArray<NSString *> *errorClasses = @[@"EXC_BAD_ACCESS",
+                                          @"EXC_BAD_INSTRUCTION",
+                                          @"EXC_BREAKPOINT",
+                                          @"Exception",
+                                          @"Fatal error",
+                                          @"NSError",
+                                          @"NSGenericException",
+                                          @"NSInternalInconsistencyException",
+                                          @"NSMallocException",
+                                          @"NSRangeException",
+                                          @"SIGABRT",
+                                          @"UIViewControllerHierarchyInconsistency",
+                                          @"std::__1::system_error"];
+
+    __block NSArray *discarded, *kept;
+
+    void (^ applyDiscardClasses)(NSSet *) = ^(NSSet *discardClasses){
+        BugsnagConfiguration *configuration = [[BugsnagConfiguration alloc] initWithApiKey:DUMMY_APIKEY_32CHAR_1];
+        configuration.discardClasses = discardClasses;
+        NSPredicate *shouldDiscard = [NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) {
+            return [configuration shouldDiscardErrorClass:evaluatedObject];
+        }];
+        discarded = [errorClasses filteredArrayUsingPredicate:shouldDiscard];
+        kept = [errorClasses filteredArrayUsingPredicate:[NSCompoundPredicate notPredicateWithSubpredicate:shouldDiscard]];
+    };
+
+    applyDiscardClasses(nil);
+    XCTAssertEqualObjects(discarded, @[]);
+    XCTAssertEqualObjects(kept, errorClasses);
+
+    applyDiscardClasses([NSSet setWithObjects:@"nserror", nil]);
+    XCTAssertEqualObjects(discarded, @[]);
+    XCTAssertEqualObjects(kept, errorClasses);
+
+    applyDiscardClasses([NSSet setWithObjects:@"EXC_BAD_ACCESS", @"NSError", nil]);
+    XCTAssertEqualObjects(discarded, (@[@"EXC_BAD_ACCESS", @"NSError"]));
+    XCTAssertEqualObjects(kept, (@[@"EXC_BAD_INSTRUCTION",
+                                   @"EXC_BREAKPOINT",
+                                   @"Exception",
+                                   @"Fatal error",
+                                   @"NSGenericException",
+                                   @"NSInternalInconsistencyException",
+                                   @"NSMallocException",
+                                   @"NSRangeException",
+                                   @"SIGABRT",
+                                   @"UIViewControllerHierarchyInconsistency",
+                                   @"std::__1::system_error"]));
+
+    applyDiscardClasses([NSSet setWithObjects:@"Exception", @"NSError",
+                         [NSRegularExpression regularExpressionWithPattern:@"std::__1::.*" options:0 error:nil], nil]);
+    XCTAssertEqualObjects(discarded, (@[@"Exception", @"NSError", @"std::__1::system_error"]));
+    XCTAssertEqualObjects(kept, (@[@"EXC_BAD_ACCESS",
+                                   @"EXC_BAD_INSTRUCTION",
+                                   @"EXC_BREAKPOINT",
+                                   @"Fatal error",
+                                   @"NSGenericException",
+                                   @"NSInternalInconsistencyException",
+                                   @"NSMallocException",
+                                   @"NSRangeException",
+                                   @"SIGABRT",
+                                   @"UIViewControllerHierarchyInconsistency"]));
+
+    applyDiscardClasses([NSSet setWithObjects:[NSRegularExpression regularExpressionWithPattern:@".*" options:0 error:nil], nil]);
+    XCTAssertEqualObjects(discarded, errorClasses);
+    XCTAssertEqualObjects(kept, (@[]));
+}
+
 @end

features/discard_classes.feature

@@ -0,0 +1,21 @@
+Feature: Configuration discardClasses option
+
+  Background:
+    Given I clear all persistent data
+
+  Scenario: Discard handled exception via regular expression
+    When I run "DiscardClassesHandledExceptionRegexScenario"
+    And I wait to receive a request
+    And the exception "errorClass" equals "NotDiscarded"
+
+  Scenario: Discard unhandled exception
+    When I run "DiscardClassesUnhandledExceptionScenario" and relaunch the app
+    And I configure Bugsnag for "DiscardClassesUnhandledExceptionScenario"
+    And I wait to receive a request
+    And the exception "errorClass" equals "NotDiscarded"
+
+  Scenario: Discard unhandled crash
+    When I run "DiscardClassesUnhandledCrashScenario" and relaunch the app
+    And I configure Bugsnag for "DiscardClassesUnhandledCrashScenario"
+    And I wait to receive a request
+    And the exception "errorClass" equals "NotDiscarded"

features/fixtures/ios-swift-cocoapods/iOSTestApp.xcodeproj/project.pbxproj

@@ -16,6 +16,7 @@
 		00432CC4240912A100826D05 /* EnabledErrorTypesCxxScenario.mm in Sources */ = {isa = PBXBuildFile; fileRef = 00432CC2240912A000826D05 /* EnabledErrorTypesCxxScenario.mm */; };
 		00507A64242BFE5600EF1B87 /* EnabledBreadcrumbTypesIsNilScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 00507A63242BFE5600EF1B87 /* EnabledBreadcrumbTypesIsNilScenario.swift */; };
 		00CEB60D24080C690004793D /* EnabledErrorTypesScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 00CEB60C24080C690004793D /* EnabledErrorTypesScenario.m */; };
+		0163BFA72583B3CF008DC28B /* DiscardClassesScenarios.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0163BFA62583B3CF008DC28B /* DiscardClassesScenarios.swift */; };
 		6526A0D4248A83350002E2C9 /* LoadConfigFromFileAutoScenario.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6526A0D3248A83350002E2C9 /* LoadConfigFromFileAutoScenario.swift */; };
 		8A14F0F62282D4AE00337B05 /* (null) in Sources */ = {isa = PBXBuildFile; };
 		8A32DB8222424E3000EDD92F /* NSExceptionShiftScenario.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A32DB8122424E3000EDD92F /* NSExceptionShiftScenario.m */; };
@@ -159,6 +160,7 @@
 		00A98315240DBB7A0016A57E /* out_of_memory.feature */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; name = out_of_memory.feature; path = ../../../out_of_memory.feature; sourceTree = "<group>"; };
 		00CEB60B24080C690004793D /* EnabledErrorTypesScenario.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = EnabledErrorTypesScenario.h; sourceTree = "<group>"; };
 		00CEB60C24080C690004793D /* EnabledErrorTypesScenario.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = EnabledErrorTypesScenario.m; sourceTree = "<group>"; };
+		0163BFA62583B3CF008DC28B /* DiscardClassesScenarios.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DiscardClassesScenarios.swift; sourceTree = "<group>"; };
 		4994F05E0421A0B037DD2CC5 /* Pods_iOSTestApp.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_iOSTestApp.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		6526A0D3248A83350002E2C9 /* LoadConfigFromFileAutoScenario.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LoadConfigFromFileAutoScenario.swift; sourceTree = "<group>"; };
 		8A32DB8022424E3000EDD92F /* NSExceptionShiftScenario.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = NSExceptionShiftScenario.h; sourceTree = "<group>"; };
@@ -549,6 +551,7 @@
 				F49695A3243EF7B600105DA9 /* OOMs */,
 				F49695AE2445476700105DA9 /* Plugin */,
 				0037410E2473CF2300BE41AA /* AppAndDeviceAttributesScenario.swift */,
+				0163BFA62583B3CF008DC28B /* DiscardClassesScenarios.swift */,
 				8AB1081823301FE600672818 /* ReleaseStageScenarios.swift */,
 				F4295ABA693D273D52AA9F6B /* Scenario.h */,
 				F42954E8B66F3FB7F5333CF7 /* Scenario.m */,
@@ -877,6 +880,7 @@
 				8AB65FCC22DC77CB001200AB /* LoadConfigFromFileScenario.swift in Sources */,
 				E7B79CD4247FD6760039FB88 /* ManualContextOnErrorScenario.swift in Sources */,
 				E7767F13221C21E30006648C /* ResumedSessionScenario.swift in Sources */,
+				0163BFA72583B3CF008DC28B /* DiscardClassesScenarios.swift in Sources */,
 				E700EE69247D73F8008CFFB6 /* UnhandledMachExceptionScenario.m in Sources */,
 				E75040B12478214F005D33BD /* MetadataRedactionRegexScenario.swift in Sources */,
 				E700EE5B247D3224008CFFB6 /* OriginalErrorNSExceptionScenario.swift in Sources */,

features/fixtures/macos/macOSTestApp.xcodeproj/project.pbxproj

@@ -9,6 +9,7 @@
 /* Begin PBXBuildFile section */
 		01452354254AFD7C00D436AA /* Bugsnag.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 01452353254AFD7C00D436AA /* Bugsnag.framework */; };
 		01452355254AFD7C00D436AA /* Bugsnag.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 01452353254AFD7C00D436AA /* Bugsnag.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		0163BF9B2583AF2A008DC28B /* DiscardClassesScenarios.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0163BF9A2583AF2A008DC28B /* DiscardClassesScenarios.swift */; };
 		0176C0AE254AE81B0066E0F3 /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = 0176C0AD254AE81B0066E0F3 /* main.m */; };
 		0176C0B1254AE81B0066E0F3 /* AppDelegate.m in Sources */ = {isa = PBXBuildFile; fileRef = 0176C0B0254AE81B0066E0F3 /* AppDelegate.m */; };
 		0176C0B3254AE81B0066E0F3 /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 0176C0B2254AE81B0066E0F3 /* Images.xcassets */; };
@@ -146,6 +147,7 @@
 /* Begin PBXFileReference section */
 		01452353254AFD7C00D436AA /* Bugsnag.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = Bugsnag.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		01452360254AFEA700D436AA /* macOSTestApp-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "macOSTestApp-Bridging-Header.h"; sourceTree = "<group>"; };
+		0163BF9A2583AF2A008DC28B /* DiscardClassesScenarios.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DiscardClassesScenarios.swift; sourceTree = "<group>"; };
 		0176C0A8254AE81B0066E0F3 /* macOSTestApp.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = macOSTestApp.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		0176C0AC254AE81B0066E0F3 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; usesTabs = 1; };
 		0176C0AD254AE81B0066E0F3 /* main.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = main.m; sourceTree = "<group>"; };
@@ -380,6 +382,7 @@
 				01F47C8F254B1B2F00B184AD /* CxxExceptionScenario.mm */,
 				01F47C43254B1B2D00B184AD /* DisabledSessionTrackingScenario.h */,
 				01F47C88254B1B2F00B184AD /* DisabledSessionTrackingScenario.m */,
+				0163BF9A2583AF2A008DC28B /* DiscardClassesScenarios.swift */,
 				01F47CA8254B1B3000B184AD /* DiscardedBreadcrumbTypeScenario.swift */,
 				01F47CB6254B1B3000B184AD /* DiscardSessionScenario.swift */,
 				01F47C3D254B1B2D00B184AD /* EnabledBreadcrumbTypesIsNilScenario.swift */,
@@ -402,6 +405,8 @@
 				01F47C56254B1B2E00B184AD /* ManualSessionWithUserScenario.m */,
 				01F47C33254B1B2D00B184AD /* ManyConcurrentNotifyScenario.h */,
 				01F47C6E254B1B2E00B184AD /* ManyConcurrentNotifyScenario.m */,
+				CBB7878D2578FB3F0071BDE4 /* MarkUnhandledHandledScenario.h */,
+				CBB7878C2578FB3F0071BDE4 /* MarkUnhandledHandledScenario.m */,
 				01F47CBD254B1B3000B184AD /* MetadataMergeScenario.swift */,
 				01F47C29254B1B2C00B184AD /* MetadataRedactionDefaultScenario.swift */,
 				01F47C80254B1B2F00B184AD /* MetadataRedactionNestedScenario.swift */,
@@ -489,8 +494,6 @@
 				01F47C90254B1B2F00B184AD /* UnhandledInternalNotifyScenario.swift */,
 				01F47C38254B1B2D00B184AD /* UnhandledMachExceptionScenario.h */,
 				01F47C4C254B1B2D00B184AD /* UnhandledMachExceptionScenario.m */,
-				CBB7878D2578FB3F0071BDE4 /* MarkUnhandledHandledScenario.h */,
-				CBB7878C2578FB3F0071BDE4 /* MarkUnhandledHandledScenario.m */,
 				01F47CB7254B1B3000B184AD /* UserDefaultInfoScenario.swift */,
 				01F47CB3254B1B3000B184AD /* UserDisabledScenario.swift */,
 				01F47C75254B1B2E00B184AD /* UserEmailScenario.swift */,
@@ -686,6 +689,7 @@
 				017FBFB8254B09C300809042 /* MainWindowController.m in Sources */,
 				01F47CF0254B1B3100B184AD /* OnSendOverwriteScenario.swift in Sources */,
 				01F47D1B254B1B3100B184AD /* SIGSEGVScenario.m in Sources */,
+				0163BF9B2583AF2A008DC28B /* DiscardClassesScenarios.swift in Sources */,
 				01F47D09254B1B3100B184AD /* BreadcrumbCallbackOverrideScenario.swift in Sources */,
 				0176C0B1254AE81B0066E0F3 /* AppDelegate.m in Sources */,
 				01F47CD7254B1B3100B184AD /* AutoDetectFalseHandledScenario.swift in Sources */,

features/fixtures/shared/scenarios/DiscardClassesScenarios.swift

@@ -0,0 +1,77 @@
+//
+//  DiscardClassesScenarios.swift
+//  macOSTestApp
+//
+//  Created by Nick Dowell on 11/12/2020.
+//  Copyright © 2020 Bugsnag Inc. All rights reserved.
+//
+
+extension NSExceptionName {
+
+    /// An exception name that should not be discarded by the discardClasses values in these scenarios.
+    static let notDiscarded = NSExceptionName("NotDiscarded")
+}
+
+// MARK: -
+
+class DiscardClassesHandledExceptionRegexScenario: Scenario {
+
+    override func startBugsnag() {
+        config.autoTrackSessions = false
+        config.discardClasses = try! [NSRegularExpression(pattern: #"NS\w+Exception"#)]
+        super.startBugsnag()
+    }
+
+    override func run() {
+        Bugsnag.notify(NSException(name: .genericException, reason: "This exception should be discarded")) { _ in
+            fatalError("OnError should not be called for discarded errors")
+        }
+        Bugsnag.notify(NSException(name: .notDiscarded, reason: "This exception should not be discarded"))
+    }
+}
+
+// MARK: -
+
+class DiscardClassesUnhandledExceptionScenario: Scenario {
+
+    override func startBugsnag() {
+        config.autoTrackSessions = false
+        config.discardClasses = [NSExceptionName.rangeException.rawValue]
+        config.addOnSendError {
+            precondition(!$0.unhandled, "OnSendError should not be called for discarded errors (NSRangeException)")
+            return true
+        }
+        super.startBugsnag()
+
+        if Bugsnag.appDidCrashLastLaunch() {
+            Bugsnag.notify(NSException(name: .notDiscarded, reason: "This exception should not be discarded"))
+        }
+    }
+
+    override func run() {
+        NSArray().object(at: 0)
+    }
+}
+
+// MARK: -
+
+class DiscardClassesUnhandledCrashScenario: Scenario {
+
+    override func startBugsnag() {
+        config.autoTrackSessions = false
+        config.discardClasses = ["EXC_BREAKPOINT"]
+        config.addOnSendError {
+            precondition(!$0.unhandled, "OnSendError should not be called for discarded errors (EXC_BREAKPOINT)")
+            return true
+        }
+        super.startBugsnag()
+
+        if Bugsnag.appDidCrashLastLaunch() {
+            Bugsnag.notify(NSException(name: .notDiscarded, reason: "This exception should not be discarded"))
+        }
+    }
+
+    override func run() {
+        triggerExcBreakpoint()
+    }
+}

features/fixtures/shared/scenarios/Scenario.h

@@ -26,5 +26,8 @@ void markErrorHandledCallback(const BSG_KSCrashReportWriter * _Nonnull writer);
 
 - (void)didEnterBackgroundNotification;
 
+- (void)triggerExcBreakpoint;
+
 @property (nonatomic, strong, nullable) NSString *eventMode;
+
 @end

features/fixtures/shared/scenarios/Scenario.m

@@ -55,4 +55,8 @@ - (void)startBugsnag {
 - (void)didEnterBackgroundNotification {
 }
 
+- (void)triggerExcBreakpoint {
+    __builtin_trap();
+}
+
 @end