Rework exceptions and stacktraces

dio/lib/src/adapters/browser_adapter.dart

@@ -110,7 +110,6 @@ class BrowserHttpClientAdapter implements HttpClientAdapter {
               requestOptions: options,
               timeout: connectionTimeout,
             ),
-            StackTrace.current,
           );
         },
       );
@@ -224,7 +223,7 @@ class BrowserHttpClientAdapter implements HttpClientAdapter {
           completer.completeError(
             DioException.requestCancelled(
               requestOptions: options,
-              reason: 'The XMLHttpRequest was aborted.',
+              cause: 'The XMLHttpRequest was aborted.',
             ),
           );
         }

dio/lib/src/adapters/io_adapter.dart

@@ -107,13 +107,13 @@ class IOHttpClientAdapter implements HttpClientAdapter {
           timeout: options.connectTimeout ??
               httpClient.connectionTimeout ??
               Duration.zero,
-          error: e,
+          cause: e,
         );
       }
       throw DioException.connectionError(
         requestOptions: options,
         reason: e.message,
-        error: e,
+        cause: e,
       );
     }
 
@@ -169,7 +169,7 @@ class IOHttpClientAdapter implements HttpClientAdapter {
         throw DioException(
           requestOptions: options,
           type: DioExceptionType.badCertificate,
-          error: responseStream.certificate,
+          cause: responseStream.certificate,
           message: 'The certificate of the response is not approved.',
         );
       }

dio/lib/src/cancel_token.dart

@@ -37,8 +37,8 @@ class CancelToken {
   void cancel([Object? reason]) {
     _cancelError = DioException.requestCancelled(
       requestOptions: requestOptions ?? RequestOptions(),
-      reason: reason,
-      stackTrace: StackTrace.current,
+      cause: reason,
+      causeStackTrace: StackTrace.current,
     );
     if (!_completer.isCompleted) {
       _completer.complete(_cancelError);

dio/lib/src/dio/dio_for_native.dart

@@ -147,7 +147,7 @@ class DioForNative with DioMixin implements Dio {
             }
           } finally {
             completer.completeError(
-              DioMixin.assureDioException(e, response.requestOptions),
+              assureDioException(e, response.requestOptions),
             );
           }
         });
@@ -160,7 +160,7 @@ class DioForNative with DioMixin implements Dio {
           completer.complete(response);
         } catch (e) {
           completer.completeError(
-            DioMixin.assureDioException(e, response.requestOptions),
+            assureDioException(e, response.requestOptions),
           );
         }
       },
@@ -169,7 +169,7 @@ class DioForNative with DioMixin implements Dio {
           await closeAndDelete();
         } finally {
           completer.completeError(
-            DioMixin.assureDioException(e, response.requestOptions),
+            assureDioException(e, response.requestOptions),
           );
         }
       },
@@ -190,10 +190,10 @@ class DioForNative with DioMixin implements Dio {
             throw DioException.receiveTimeout(
               timeout: timeout,
               requestOptions: response.requestOptions,
-              error: e,
+              cause: e,
             );
           } else {
-            throw e;
+            throw assureDioException(e, response.requestOptions);
           }
         },
       );

dio/lib/src/dio_exception.dart

@@ -27,7 +27,7 @@ enum DioExceptionType {
   connectionError,
 
   /// Default error type, Some other [Error]. In this case, you can use the
-  /// [DioException.error] if it is not null.
+  /// [DioException.cause] if it is not null.
   unknown,
 }
 
@@ -62,14 +62,10 @@ class DioException implements Exception {
     required this.requestOptions,
     this.response,
     this.type = DioExceptionType.unknown,
-    this.error,
-    StackTrace? stackTrace,
+    this.cause,
+    StackTrace? causeStackTrace,
     this.message,
-  }) : stackTrace = identical(stackTrace, StackTrace.empty)
-            ? requestOptions.sourceStackTrace ?? StackTrace.current
-            : stackTrace ??
-                requestOptions.sourceStackTrace ??
-                StackTrace.current;
+  }) : _causeStackTrace = causeStackTrace;
 
   factory DioException.badResponse({
     required int statusCode,
@@ -82,21 +78,21 @@ class DioException implements Exception {
             'invalid status code of $statusCode.',
         requestOptions: requestOptions,
         response: response,
-        error: null,
+        cause: null,
       );
 
   factory DioException.connectionTimeout({
     required Duration timeout,
     required RequestOptions requestOptions,
-    Object? error,
+    Object? cause,
   }) =>
       DioException(
         type: DioExceptionType.connectionTimeout,
         message: 'The request connection took '
             'longer than $timeout. It was aborted.',
         requestOptions: requestOptions,
         response: null,
-        error: error,
+        cause: cause,
       );
 
   factory DioException.sendTimeout({
@@ -109,48 +105,48 @@ class DioException implements Exception {
             'longer than $timeout to send data. It was aborted.',
         requestOptions: requestOptions,
         response: null,
-        error: null,
+        cause: null,
       );
 
   factory DioException.receiveTimeout({
     required Duration timeout,
     required RequestOptions requestOptions,
-    Object? error,
+    Object? cause,
   }) =>
       DioException(
         type: DioExceptionType.receiveTimeout,
         message: 'The request took '
             'longer than $timeout to receive data. It was aborted.',
         requestOptions: requestOptions,
         response: null,
-        error: error,
+        cause: cause,
       );
 
   factory DioException.requestCancelled({
     required RequestOptions requestOptions,
-    required Object? reason,
-    StackTrace? stackTrace,
+    required Object? cause,
+    StackTrace? causeStackTrace,
   }) =>
       DioException(
         type: DioExceptionType.cancel,
         message: 'The request was cancelled.',
         requestOptions: requestOptions,
         response: null,
-        error: reason,
-        stackTrace: stackTrace,
+        cause: cause,
+        causeStackTrace: causeStackTrace,
       );
 
   factory DioException.connectionError({
     required RequestOptions requestOptions,
     required String reason,
-    Object? error,
+    Object? cause,
   }) =>
       DioException(
         type: DioExceptionType.connectionError,
         message: 'The connection errored: $reason',
         requestOptions: requestOptions,
         response: null,
-        error: error,
+        cause: cause,
       );
 
   /// The request info for the request that throws exception.
@@ -164,11 +160,14 @@ class DioException implements Exception {
 
   /// The original error/exception object;
   /// It's usually not null when `type` is [DioExceptionType.unknown].
-  final Object? error;
+  final Object? cause;
 
   /// The stacktrace of the original error/exception object;
   /// It's usually not null when `type` is [DioExceptionType.unknown].
-  final StackTrace stackTrace;
+  final StackTrace? _causeStackTrace;
+
+  StackTrace? get causeStackTrace =>
+      _causeStackTrace ?? (cause is Error ? (cause as Error).stackTrace : null);
 
   /// The error message that throws a [DioException].
   final String? message;
@@ -178,25 +177,25 @@ class DioException implements Exception {
     RequestOptions? requestOptions,
     Response? response,
     DioExceptionType? type,
-    Object? error,
-    StackTrace? stackTrace,
+    Object? cause,
+    StackTrace? causeStackTrace,
     String? message,
   }) {
     return DioException(
       requestOptions: requestOptions ?? this.requestOptions,
       response: response ?? this.response,
       type: type ?? this.type,
-      error: error ?? this.error,
-      stackTrace: stackTrace ?? this.stackTrace,
+      cause: cause ?? this.cause,
+      causeStackTrace: causeStackTrace ?? this.causeStackTrace,
       message: message ?? this.message,
     );
   }
 
   @override
   String toString() {
     String msg = 'DioException [${type.toPrettyDescription()}]: $message';
-    if (error != null) {
-      msg += '\nError: $error';
+    if (cause != null) {
+      msg += '\nError: $cause';
     }
     return msg;
   }