Feature: Improve Dio exception reports (#718)

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 * [Dio] Ref: Replace FailedRequestAdapter with FailedRequestInterceptor (#728)
 * Fix: Add missing return values - dart analyzer (#742)
+* Feature: Add `DioEventProcessor` which improves DioError crash reports (#718)
 * Fix: Do not report duplicated packages and integrations (#760)
 
 # 6.3.0

dart/lib/src/http_client/failed_request_client.dart

@@ -217,22 +217,3 @@ extension _ListX on List<SentryStatusCode> {
     return any((element) => element.isInRange(statusCode));
   }
 }
-
-extension _MaxRequestBodySizeX on MaxRequestBodySize {
-  bool shouldAddBody(int contentLength) {
-    if (this == MaxRequestBodySize.never) {
-      return false;
-    }
-    if (this == MaxRequestBodySize.always) {
-      return true;
-    }
-    if (this == MaxRequestBodySize.medium && contentLength <= 10000) {
-      return true;
-    }
-
-    if (this == MaxRequestBodySize.small && contentLength <= 4000) {
-      return true;
-    }
-    return false;
-  }
-}

dart/lib/src/protocol/max_request_body_size.dart

@@ -15,3 +15,22 @@ enum MaxRequestBodySize {
   /// make sense of it
   always,
 }
+
+extension MaxRequestBodySizeX on MaxRequestBodySize {
+  bool shouldAddBody(int contentLength) {
+    if (this == MaxRequestBodySize.never) {
+      return false;
+    }
+    if (this == MaxRequestBodySize.always) {
+      return true;
+    }
+    if (this == MaxRequestBodySize.medium && contentLength <= 10000) {
+      return true;
+    }
+
+    if (this == MaxRequestBodySize.small && contentLength <= 4000) {
+      return true;
+    }
+    return false;
+  }
+}

dio/lib/sentry_dio.dart

@@ -1,3 +1,7 @@
 library sentry_dio;
 
 export 'src/sentry_dio_extension.dart';
+
+// Export the processor in case people want to use it standalone.
+// Normally one doesn't need to use it directly.
+export 'src/dio_event_processor.dart';

dio/lib/src/dio_event_processor.dart

@@ -0,0 +1,137 @@
+import 'dart:async';
+
+import 'package:dio/dio.dart';
+import 'package:sentry/sentry.dart';
+// ignore: implementation_imports
+import 'package:sentry/src/sentry_exception_factory.dart';
+
+/// This is an [EventProcessor], which improves crash reports of [DioError]s.
+/// It adds information about [DioError.response] if present and also about
+/// the inner exceptions.
+class DioEventProcessor implements EventProcessor {
+  /// This is an [EventProcessor], which improves crash reports of [DioError]s.
+  DioEventProcessor(this._options, this._maxRequestBodySize);
+
+  final SentryOptions _options;
+  final MaxRequestBodySize _maxRequestBodySize;
+
+  SentryExceptionFactory get _sentryExceptionFactory =>
+      // ignore: invalid_use_of_internal_member
+      _options.exceptionFactory;
+
+  @override
+  FutureOr<SentryEvent?> apply(SentryEvent event, {dynamic hint}) {
+    final dynamic dioError = event.throwable;
+    if (dioError is! DioError) {
+      return event;
+    }
+
+    // Don't override just parts of the original request.
+    // Keep the original one or if there's none create one.
+    event = event.copyWith(request: event.request ?? _requestFrom(dioError));
+
+    final innerDioStackTrace = dioError.stackTrace;
+    final innerDioErrorException = dioError.error as Object?;
+
+    // If the inner errors stacktrace is null,
+    // there's nothing to create chained exception
+    if (innerDioStackTrace == null) {
+      return event;
+    }
+
+    try {
+      final innerException = _sentryExceptionFactory.getSentryException(
+        innerDioErrorException ?? 'DioError inner stacktrace',
+        stackTrace: innerDioStackTrace,
+      );
+
+      final exceptions = _removeDioErrorStackTraceFromValue(
+        List<SentryException>.from(event.exceptions ?? <SentryException>[]),
+        dioError,
+      );
+
+      return event.copyWith(
+        exceptions: [
+          innerException,
+          ...exceptions,
+        ],
+      );
+    } catch (e, stackTrace) {
+      _options.logger(
+        SentryLevel.debug,
+        'Could not convert DioError to SentryException',
+        exception: e,
+        stackTrace: stackTrace,
+      );
+    }
+    return event;
+  }
+
+  /// Remove the StackTrace from [dioError] so the message on Sentry looks
+  /// much better.
+  List<SentryException> _removeDioErrorStackTraceFromValue(
+    List<SentryException> exceptions,
+    DioError dioError,
+  ) {
+    var dioSentryException = exceptions
+        .where((element) => element.type == dioError.runtimeType.toString())
+        .first;
+
+    final exceptionIndex = exceptions.indexOf(dioSentryException);
+    exceptions.remove(dioSentryException);
+
+    // Remove error and stacktrace, so that the DioError value doesn't
+    // include the chained exception.
+    dioError.stackTrace = null;
+    dioError.error = null;
+
+    dioSentryException = dioSentryException.copyWith(
+      value: dioError.toString(),
+    );
+
+    exceptions.insert(exceptionIndex, dioSentryException);
+
+    return exceptions;
+  }
+
+  SentryRequest? _requestFrom(DioError dioError) {
+    final options = dioError.requestOptions;
+    // As far as I can tell there's no way to get the uri without the query part
+    // so we replace it with an empty string.
+    final urlWithoutQuery = options.uri.replace(query: '').toString();
+
+    final query = options.uri.query.isEmpty ? null : options.uri.query;
+
+    final headers = options.headers
+        .map((key, dynamic value) => MapEntry(key, value?.toString() ?? ''));
+
+    return SentryRequest(
+      method: options.method,
+      headers: _options.sendDefaultPii ? headers : null,
+      url: urlWithoutQuery,
+      queryString: query,
+      cookies: _options.sendDefaultPii
+          ? options.headers['Cookie']?.toString()
+          : null,
+      data: _getRequestData(dioError.response?.data),
+    );
+  }
+
+  /// Returns the request data, if possible according to the users settings.
+  /// Type checks are based on DIOs [ResponseType].
+  Object? _getRequestData(dynamic data) {
+    if (!_options.sendDefaultPii) {
+      return null;
+    }
+    if (data is String) {
+      if (_maxRequestBodySize.shouldAddBody(data.codeUnits.length)) {
+        return data;
+      }
+    } else if (data is List<int>) {
+      if (_maxRequestBodySize.shouldAddBody(data.length)) {
+        return data;
+      }
+    }
+    return null;
+  }
+}

dio/lib/src/sentry_dio_extension.dart

@@ -1,6 +1,7 @@
 import 'package:dio/dio.dart';
 import 'package:meta/meta.dart';
 import 'package:sentry/sentry.dart';
+import 'dio_event_processor.dart';
 import 'failed_request_interceptor.dart';
 import 'sentry_transformer.dart';
 import 'sentry_dio_client_adapter.dart';
@@ -16,10 +17,20 @@ extension SentryDioExtension on Dio {
     bool recordBreadcrumbs = true,
     bool networkTracing = true,
     MaxRequestBodySize maxRequestBodySize = MaxRequestBodySize.never,
-    List<SentryStatusCode> failedRequestStatusCodes = const [],
     bool captureFailedRequests = false,
-    bool sendDefaultPii = false,
+    Hub? hub,
   }) {
+    hub = hub ?? HubAdapter();
+
+    // ignore: invalid_use_of_internal_member
+    final options = hub.options;
+
+    // Add DioEventProcessor when it's not already present
+    if (options.eventProcessors.whereType<DioEventProcessor>().isEmpty) {
+      options.sdk.addIntegration('sentry_dio');
+      options.addEventProcessor(DioEventProcessor(options, maxRequestBodySize));
+    }
+
     if (captureFailedRequests) {
       // Add FailedRequestInterceptor at index 0, so it's the first interceptor.
       // This ensures that it is called and not skipped by any previous interceptor.
@@ -31,9 +42,13 @@ extension SentryDioExtension on Dio {
       client: httpClientAdapter,
       recordBreadcrumbs: recordBreadcrumbs,
       networkTracing: networkTracing,
+      hub: hub,
     );
 
     // intercept transformations
-    transformer = SentryTransformer(transformer: transformer);
+    transformer = SentryTransformer(
+      transformer: transformer,
+      hub: hub,
+    );
   }
 }