Fix service test websocket error edge case

runtime/observatory/tests/service/test_helper.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test_helper;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'package:observatory/service_io.dart';
 import 'package:stack_trace/stack_trace.dart';
 import 'service_test_common.dart';
 
 /// Will be set to the http address of the VM's service protocol before
 /// any tests are invoked.
 String serviceHttpAddress;
 String serviceWebsocketAddress;
 
-bool _isWebSocketDisconnect(e) {
-  return e is NetworkRpcException;
-}
-
-
 const String _TESTEE_ENV_KEY = 'SERVICE_TEST_TESTEE';
 const Map<String, String> _TESTEE_SPAWN_ENV = const {
   _TESTEE_ENV_KEY: 'true'
 };
 bool _isTestee() {
   return Platform.environment.containsKey(_TESTEE_ENV_KEY);
 }
 
 const String _SKY_SHELL_ENV_KEY = 'SERVICE_TEST_SKY_SHELL';
 bool _shouldLaunchSkyShell() {
@@ skipping 262 matching lines @@
         var isolate = await vm.isolates.first.load();
         var testIndex = 1;
         var totalTests = isolateTests.length;
         for (var test in isolateTests) {
           vm.verbose = verbose_vm;
           print('Running $name [$testIndex/$totalTests]');
           testIndex++;
           await test(isolate);
         }
       }
-    }, onError: (e, st) {
-        if (!_isWebSocketDisconnect(e)) {
-          print('Unexpected exception in service tests: $e $st');
-          throw e;
-        }
+    }, onError: (error, stackTrace) {
+      print('Unexpected exception in service tests: $error\n$stackTrace');
     });
   }
 }
 
 void suppressWarning() {
   new _FlutterDeviceServiceTesterRunner();
 }
 
 class _ServiceTesterRunner {
   void run({List<String> mainArgs,
@@ skipping 44 matching lines @@
           var totalTests = isolateTests.length;
           for (var test in isolateTests) {
             vm.verbose = verbose_vm;
             print('Running $name [$testIndex/$totalTests]');
             testIndex++;
             await test(isolate);
           }
         }
 
         await process.requestExit();
-      }, onError: (e, st) {
+      }, onError: (error, stackTrace) {
         process.requestExit();
-        // TODO: remove this workaround.
-        // This is necessary due to non awaited operations.
-        // E.G. object.dart (398~402)
-        // When an exception is thrown inside a test (directly or via await) the
-        // stacktrace is non-null and shows where the exception has been thrown.
-        // If vice versa the exception is due to an error in a non-awaited
-        // Future the stacktrace is null.
-        if (st != null || !_isWebSocketDisconnect(e)) {
-          print('Unexpected exception in service tests: $e $st');
-          throw e;
-        }
+        print('Unexpected exception in service tests: $error\n$stackTrace');
+        throw error;
       });
     });
   }
 }
 
 /// Runs [tests] in sequence, each of which should take an [Isolate] and
 /// return a [Future]. Code for setting up state can run before and/or
 /// concurrently with the tests. Uses [mainArgs] to determine whether
 /// to run tests or testee in this invokation of the script.
 Future runIsolateTests(List<String> mainArgs,
@@ skipping 88 matching lines @@
         mainArgs: mainArgs,
         vmTests: tests,
         pause_on_start: pause_on_start,
         pause_on_exit: pause_on_exit,
         trace_service: trace_service,
         trace_compiler: trace_compiler,
         verbose_vm: verbose_vm,
         pause_on_unhandled_exceptions: pause_on_unhandled_exceptions);
   }
 }