Reland improvements to causal async stack traces

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;
 
 const String _TESTEE_ENV_KEY = 'SERVICE_TEST_TESTEE';
 const Map<String, String> _TESTEE_SPAWN_ENV = const {
   _TESTEE_ENV_KEY: 'true'
@@ skipping 253 matching lines @@
             List<VMTest> vmTests,
             List<IsolateTest> isolateTests,
             bool pause_on_start: false,
             bool pause_on_exit: false,
             bool verbose_vm: false,
             bool pause_on_unhandled_exceptions: false,
             bool testeeControlsServer: false,
             bool useAuthToken: false}) {
     var process = new _ServiceTesteeLauncher();
     bool testsDone = false;
-    process.launch(pause_on_start, pause_on_exit,
+    runZoned(() {
+      process.launch(pause_on_start, pause_on_exit,
                    pause_on_unhandled_exceptions,
                    testeeControlsServer,
                    useAuthToken, extraArgs).then((Uri serverAddress) async {
-      if (mainArgs.contains("--gdb")) {
-        var pid = process.process.pid;
-        var wait = new Duration(seconds: 10);
-        print("Testee has pid $pid, waiting $wait before continuing");
-        sleep(wait);
-      }
-      setupAddresses(serverAddress);
-      var name = Platform.script.pathSegments.last;
-      Chain.capture(() async {
+        if (mainArgs.contains("--gdb")) {
+          var pid = process.process.pid;
+          var wait = new Duration(seconds: 10);
+          print("Testee has pid $pid, waiting $wait before continuing");
+          sleep(wait);
+        }
+        setupAddresses(serverAddress);
+        var name = Platform.script.pathSegments.last;
         var vm =
             new WebSocketVM(new WebSocketVMTarget(serviceWebsocketAddress));
         print('Loading VM...');
         await vm.load();
         print('Done loading VM');
 
         // Run vm tests.
         if (vmTests != null) {
           var testIndex = 1;
           var totalTests = vmTests.length;
@@ skipping 14 matching lines @@
             vm.verbose = verbose_vm;
             print('Running $name [$testIndex/$totalTests]');
             testIndex++;
             await test(isolate);
           }
         }
 
         print('All service tests completed successfully.');
         testsDone = true;
         await process.requestExit();
-      }, onError: (error, stackTrace) {
-        if (testsDone) {
-          print('Ignoring late exception during process exit:\n'
-                '$error\n#stackTrace');
-        } else {
-          process.requestExit();
-          print('Unexpected exception in service tests: $error\n$stackTrace');
-          throw error;
-        }
       });
+    }, onError: (error, stackTrace) async {
+      print('onERROR FIRED!');
+      if (testsDone) {
+        print('Ignoring late exception during process exit:\n'
+              '$error\n#stackTrace');
+      } else {
+        await process.requestExit();
+        print('Unexpected exception in service tests: $error\n$stackTrace');
+        throw error;
+      }
     });
   }
 
-
-
   Future<Isolate> getFirstIsolate(WebSocketVM vm) async {
     if (vm.isolates.isNotEmpty) {
       var isolate = await vm.isolates.first.load();
       if (isolate is Isolate) {
         return isolate;
       }
     }
 
     Completer completer = new Completer();
     vm.getEventStream(VM.kIsolateStream).then((stream) {
@@ skipping 124 matching lines @@
     new _ServiceTesterRunner().run(
         mainArgs: mainArgs,
         extraArgs: extraArgs,
         vmTests: tests,
         pause_on_start: pause_on_start,
         pause_on_exit: pause_on_exit,
         verbose_vm: verbose_vm,
         pause_on_unhandled_exceptions: pause_on_unhandled_exceptions);
   }
 }