sdk/tests/lib/async/catch_errors23_test.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.

import 'dart:async';

import 'package:expect/async_helper.dart';
import 'package:expect/expect.dart';

import 'catch_errors.dart';

main() {
  asyncStart();
  Completer done = new Completer();

  var events = [];
  late StreamController controller;
  late Stream stream;
  // Test that errors are not traversing zone boundaries.
  // Note that the first listener of `asBroadcastStream` determines in which
  // zone the subscription lives.
  catchErrors(() {
    catchErrors(() {
          controller = new StreamController();

          // Assign to "global" `stream`.
          stream = controller.stream
              .map((x) {
                events.add("map $x");
                return x + 100;
              })
              .transform(
                new StreamTransformer.fromHandlers(
                  handleError: (e, st, sink) {
                    sink.add("error $e");
                  },
                ),
              )
              .asBroadcastStream();

          // Listen to `stream` in the inner zone.
          stream.listen((x) {
            events.add("stream $x");
          });
        })
        .listen((x) {
          events.add(x);
        })
        .asFuture()
        .then((_) {
          Expect.fail("Unexpected callback");
        });

    // Listen to `stream` in the outer zone.
    stream.listen((x) {
      events.add("stream2 $x");
    });

    // Feed the controller from the outer zone.
    controller.add(1);
    // `addError` does not count as zone-traversal. It should be caught by
    // the inner error handler.
    controller.addError("inner error");
    new Future.error("caught by outer");
    controller.close();
  }).listen(
    (x) {
      events.add("outer: $x");
      if (x == "caught by outer") done.complete(true);
    },
    onDone: () {
      Expect.fail("Unexpected callback");
    },
  );

  done.future.whenComplete(() {
    // Give handlers time to run.
    Timer.run(() {
      Expect.listEquals([
        "map 1",
        "stream 101",
        "stream2 101",
        "stream error inner error",
        "stream2 error inner error",
        "outer: caught by outer",
      ], events);
      asyncEnd();
    });
  });
}