Move package:testing to SDK.

pkg/testing/lib/src/zone_helper.dart

+// Copyright (c) 2016, 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.md file.
+
+/// Helper functions for running code in a Zone.
+library testing.zone_helper;
+
+import 'dart:async' show
+    Completer,
+    Future,
+    ZoneSpecification,
+    runZoned;
+
+import 'dart:isolate' show
+    Capability,
+    Isolate,
+    ReceivePort;
+
+import 'log.dart' show
+    logUncaughtError;
+
+Future runGuarded(
+    Future f(),
+    {void printLineOnStdout(line),
+     void handleLateError(error, StackTrace stackTrace)}) {
+
+  var printWrapper;
+  if (printLineOnStdout != null) {
+    printWrapper = (_1, _2, _3, String line) {
+      printLineOnStdout(line);
+    };
+  }
+
+  Completer completer = new Completer();
+
+  handleUncaughtError(error, StackTrace stackTrace) {
+    logUncaughtError(error, stackTrace);
+    if (!completer.isCompleted) {
+      completer.completeError(error, stackTrace);
+    } else if (handleLateError != null) {
+      handleLateError(error, stackTrace);
+    } else {
+      // Delegate to parent.
+      throw error;
+    }
+  }
+
+  ZoneSpecification specification = new ZoneSpecification(print: printWrapper);
+
+  ReceivePort errorPort = new ReceivePort();
+  Future errorFuture = errorPort.listen((List errors) {
+    Isolate.current.removeErrorListener(errorPort.sendPort);
+    errorPort.close();
+    var error = errors[0];
+    var stackTrace = errors[1];
+    if (stackTrace != null) {
+      stackTrace = new StackTrace.fromString(stackTrace);
+    }
+    handleUncaughtError(error, stackTrace);
+  }).asFuture();
+
+  Isolate.current.addErrorListener(errorPort.sendPort);
+  return acknowledgeControlMessages(Isolate.current).then((_) {
+    runZoned(
+        () => new Future(f).then(completer.complete),
+        zoneSpecification: specification,
+        onError: handleUncaughtError);
+
+    return completer.future.whenComplete(() {
+      errorPort.close();
+      Isolate.current.removeErrorListener(errorPort.sendPort);
+      return acknowledgeControlMessages(Isolate.current)
+          .then((_) => errorFuture);
+    });
+  });
+}
+
+/// Ping [isolate] to ensure control messages have been delivered.  Control
+/// messages are things like [Isolate.addErrorListener] and
+/// [Isolate.addOnExitListener].
+Future acknowledgeControlMessages(Isolate isolate, {Capability resume}) {
+  ReceivePort ping = new ReceivePort();
+  Isolate.current.ping(ping.sendPort);
+  if (resume == null) {
+    return ping.first;
+  } else {
+    return ping.first.then((_) => isolate.resume(resume));
+  }
+}