Add a way to extract stacktraces from custom exception types (getsentry#1335)

Author: kuhnroyal

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Features
+
+- Exception StackTrace Extractor ([#1335](https://github.com/getsentry/sentry-dart/pull/1335))
+
 ### Dependencies
 
 - Bump Cocoa SDK from v8.0.0 to v8.3.1 ([#1331](https://github.com/getsentry/sentry-dart/pull/1331))

dart/lib/sentry.dart

@@ -35,6 +35,7 @@ export 'src/type_check_hint.dart';
 // exception extraction
 export 'src/exception_cause_extractor.dart';
 export 'src/exception_cause.dart';
+export 'src/exception_stacktrace_extractor.dart';
 // Isolates
 export 'src/sentry_isolate_extension.dart';
 export 'src/sentry_isolate.dart';

dart/lib/src/exception_stacktrace_extractor.dart

@@ -0,0 +1,35 @@
+import 'protocol.dart';
+import 'sentry_options.dart';
+
+/// Sentry handles [Error.stackTrace] by default. For other cases
+/// extend this abstract class and return a custom [StackTrace] of your
+/// exceptions.
+///
+/// Implementing an extractor and providing it through
+/// [SentryOptions.addExceptionStackTraceExtractor] will enable the framework to
+/// extract the inner stacktrace and add it to [SentryException] when no other
+/// stacktrace was provided while capturing the event.
+///
+/// For an example on how to use the API refer to dio/DioStackTraceExtractor or the
+/// code below:
+///
+/// ```dart
+/// class ExceptionWithInner {
+///   ExceptionWithInner(this.innerException, this.innerStackTrace);
+///   Object innerException;
+///   dynamic innerStackTrace;
+/// }
+///
+/// class ExceptionWithInnerStackTraceExtractor extends ExceptionStackTraceExtractor<ExceptionWithInner>  {
+///   @override
+///   dynamic cause(ExceptionWithInner error) {
+///     return error.innerStackTrace;
+///   }
+/// }
+///
+/// options.addExceptionStackTraceExtractor(ExceptionWithInnerStackTraceExtractor());
+/// ```
+abstract class ExceptionStackTraceExtractor<T> {
+  dynamic stackTrace(T error);
+  Type get exceptionType => T;
+}

dart/lib/src/sentry_exception_factory.dart

@@ -30,6 +30,10 @@ class SentryExceptionFactory {
     if (throwable is Error) {
       stackTrace ??= throwable.stackTrace;
     }
+    stackTrace ??= _options
+        .exceptionStackTraceExtractor(throwable.runtimeType)
+        ?.stackTrace(throwable);
+
     // throwable.stackTrace is null if its an exception that was never thrown
     // hence we check again if stackTrace is null and if not, read the current stack trace
     // but only if attachStacktrace is enabled

dart/lib/src/sentry_options.dart

@@ -331,16 +331,28 @@ class SentryOptions {
   /// The default is 3 seconds.
   Duration? idleTimeout = Duration(seconds: 3);
 
-  final _extractorsByType = <Type, ExceptionCauseExtractor>{};
+  final _causeExtractorsByType = <Type, ExceptionCauseExtractor>{};
+
+  final _stackTraceExtractorsByType = <Type, ExceptionStackTraceExtractor>{};
 
   /// Returns a previously added [ExceptionCauseExtractor] by type
   ExceptionCauseExtractor? exceptionCauseExtractor(Type type) {
-    return _extractorsByType[type];
+    return _causeExtractorsByType[type];
   }
 
   /// Adds [ExceptionCauseExtractor] in order to extract inner exceptions
   void addExceptionCauseExtractor(ExceptionCauseExtractor extractor) {
-    _extractorsByType[extractor.exceptionType] = extractor;
+    _causeExtractorsByType[extractor.exceptionType] = extractor;
+  }
+
+  /// Returns a previously added [ExceptionStackTraceExtractor] by type
+  ExceptionStackTraceExtractor? exceptionStackTraceExtractor(Type type) {
+    return _stackTraceExtractorsByType[type];
+  }
+
+  /// Adds [ExceptionStackTraceExtractor] in order to extract inner exceptions
+  void addExceptionStackTraceExtractor(ExceptionStackTraceExtractor extractor) {
+    _stackTraceExtractorsByType[extractor.exceptionType] = extractor;
   }
 
   /// Changed SDK behaviour when set to true:

dart/test/sentry_client_test.dart

@@ -291,6 +291,32 @@ void main() {
       expect(capturedEvent.exceptions?[1].stackTrace!.frames.first.colNo, 9);
     });
 
+    test('should capture custom stacktrace', () async {
+      fixture.options.addExceptionStackTraceExtractor(
+        ExceptionWithStackTraceExtractor(),
+      );
+
+      final stackTrace = StackTrace.fromString('''
+#0      baz (file:///pathto/test.dart:50:3)
+<asynchronous suspension>
+#1      bar (file:///pathto/test.dart:46:9)
+      ''');
+
+      exception = ExceptionWithStackTrace(stackTrace);
+
+      final client = fixture.getSut(attachStacktrace: true);
+      await client.captureException(exception, stackTrace: null);
+
+      final capturedEnvelope = (fixture.transport).envelopes.first;
+      final capturedEvent = await eventFromEnvelope(capturedEnvelope);
+
+      expect(capturedEvent.exceptions?[0].stackTrace, isNotNull);
+      expect(capturedEvent.exceptions?[0].stackTrace!.frames.first.fileName,
+          'test.dart');
+      expect(capturedEvent.exceptions?[0].stackTrace!.frames.first.lineNo, 46);
+      expect(capturedEvent.exceptions?[0].stackTrace!.frames.first.colNo, 9);
+    });
+
     test('should not capture cause stacktrace when attachStacktrace is false',
         () async {
       fixture.options.addExceptionCauseExtractor(
@@ -1638,3 +1664,16 @@ class ExceptionWithCauseExtractor
     return ExceptionCause(error.cause, error.stackTrace);
   }
 }
+
+class ExceptionWithStackTrace {
+  ExceptionWithStackTrace(this.stackTrace);
+  final StackTrace stackTrace;
+}
+
+class ExceptionWithStackTraceExtractor
+    extends ExceptionStackTraceExtractor<ExceptionWithStackTrace> {
+  @override
+  StackTrace? stackTrace(ExceptionWithStackTrace error) {
+    return error.stackTrace;
+  }
+}

dart/test/sentry_exception_factory_test.dart

@@ -73,6 +73,43 @@ void main() {
     expect(sentryException.stackTrace!.frames.first.fileName, 'test.dart');
   });
 
+  test('should extract stackTrace from custom exception', () {
+    fixture.options
+        .addExceptionStackTraceExtractor(CustomExceptionStackTraceExtractor());
+
+    SentryException sentryException;
+    try {
+      throw CustomException(StackTrace.fromString('''
+#0      baz (file:///pathto/test.dart:50:3)
+<asynchronous suspension>
+#1      bar (file:///pathto/test.dart:46:9)
+      '''));
+    } catch (err, _) {
+      sentryException = fixture.getSut().getSentryException(
+            err,
+          );
+    }
+
+    expect(sentryException.type, 'CustomException');
+    expect(sentryException.stackTrace!.frames.first.lineNo, 46);
+    expect(sentryException.stackTrace!.frames.first.colNo, 9);
+    expect(sentryException.stackTrace!.frames.first.fileName, 'test.dart');
+  });
+
+  test('should not fail when stackTrace property does not exist', () {
+    SentryException sentryException;
+    try {
+      throw Object();
+    } catch (err, _) {
+      sentryException = fixture.getSut().getSentryException(
+            err,
+          );
+    }
+
+    expect(sentryException.type, 'Object');
+    expect(sentryException.stackTrace, isNotNull);
+  });
+
   test('getSentryException with not thrown Error and frames', () {
     final sentryException = fixture.getSut().getSentryException(
           CustomError(),
@@ -136,6 +173,20 @@ void main() {
 
 class CustomError extends Error {}
 
+class CustomException implements Exception {
+  final StackTrace stackTrace;
+
+  CustomException(this.stackTrace);
+}
+
+class CustomExceptionStackTraceExtractor
+    extends ExceptionStackTraceExtractor<CustomException> {
+  @override
+  StackTrace? stackTrace(CustomException error) {
+    return error.stackTrace;
+  }
+}
+
 class Fixture {
   final options = SentryOptions(dsn: fakeDsn);
 

dio/lib/src/dio_stacktrace_extractor.dart

@@ -0,0 +1,10 @@
+import 'package:dio/dio.dart';
+import 'package:sentry/sentry.dart';
+
+/// Extracts the inner stacktrace from [DioError]
+class DioStackTraceExtractor extends ExceptionStackTraceExtractor<DioError> {
+  @override
+  StackTrace? stackTrace(DioError error) {
+    return error.stackTrace;
+  }
+}

dio/lib/src/sentry_dio_extension.dart

@@ -2,6 +2,7 @@ import 'package:dio/dio.dart';
 import 'package:sentry/sentry.dart';
 import 'dio_error_extractor.dart';
 import 'dio_event_processor.dart';
+import 'dio_stacktrace_extractor.dart';
 import 'failed_request_interceptor.dart';
 import 'sentry_transformer.dart';
 import 'sentry_dio_client_adapter.dart';
@@ -50,11 +51,16 @@ extension SentryDioExtension on Dio {
     // ignore: invalid_use_of_internal_member
     final options = hub.options;
 
-    // Add to get inner exception & stacktrace
+    // Add to get inner exception
     if (options.exceptionCauseExtractor(DioError) == null) {
       options.addExceptionCauseExtractor(DioErrorExtractor());
     }
 
+    // Add to get inner stacktrace
+    if (options.exceptionStackTraceExtractor(DioError) == null) {
+      options.addExceptionStackTraceExtractor(DioStackTraceExtractor());
+    }
+
     // Add DioEventProcessor when it's not already present
     if (options.eventProcessors.whereType<DioEventProcessor>().isEmpty) {
       options.sdk.addIntegration('sentry_dio');

dio/test/dio_stacktrace_extractor_test.dart

@@ -0,0 +1,49 @@
+import 'package:dio/dio.dart';
+import 'package:sentry_dio/src/dio_stacktrace_extractor.dart';
+import 'package:test/test.dart';
+
+void main() {
+  late Fixture fixture;
+
+  setUp(() {
+    fixture = Fixture();
+  });
+
+  group(DioStackTraceExtractor, () {
+    test('extracts stacktrace', () {
+      final sut = fixture.getSut();
+      final exception = Exception('foo bar');
+      final stacktrace = StackTrace.current;
+
+      final dioError = DioError(
+        error: exception,
+        requestOptions: RequestOptions(path: '/foo/bar'),
+        stackTrace: stacktrace,
+      );
+
+      final result = sut.stackTrace(dioError);
+
+      expect(result, stacktrace);
+    });
+
+    test('extracts nothing with missing stacktrace', () {
+      final sut = fixture.getSut();
+      final exception = Exception('foo bar');
+
+      final dioError = DioError(
+        error: exception,
+        requestOptions: RequestOptions(path: '/foo/bar'),
+      );
+
+      final result = sut.stackTrace(dioError);
+
+      expect(result, isNull);
+    });
+  });
+}
+
+class Fixture {
+  DioStackTraceExtractor getSut() {
+    return DioStackTraceExtractor();
+  }
+}