LibTest/async/Stream/handleError_A01_t01.test.dart

// Copyright (c) 2011, 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.

/// @assertion Stream<T> handleError(Function onError, {bool test(error)})
/// Creates a wrapper Stream that intercepts some errors from this stream.
/// If this stream sends an error that matches test, then it is intercepted by
/// the onError function.
/// An asynchronous error e is matched by a test function if test(e) returns
/// true.
/// @description Checks that an error e intercepted by [onError] function
/// if test(e) returns true.
/// @author a.semenov@unipro.ru

library handleError_A01_t01;

import "dart:async";
import "../../../Utils/expect.dart";

void check(
    Stream s, bool test(error), List data, List intercepted, List expected) {
  List actualIntercepted = [];
  List actualErrors = [];
  List actualData = [];
  asyncStart();
  s.handleError((error) => actualIntercepted.add(error), test: test).listen(
      (data) {
    actualData.add(data);
  }, onError: (error) {
    actualErrors.add(error);
  }, onDone: () {
    Expect.listEquals(data, actualData);
    Expect.listEquals(intercepted, actualIntercepted);
    Expect.listEquals(expected, actualErrors);
    asyncEnd();
  });
}

void test(CreateStreamWithErrorsFunction create) {
  check(create([], defaultValue: 42), (x) => true, [], [], []);
  check(create([], isError: (x) => true, defaultValue: 42),
          (x) => true, [], [], []);
  check(create([1, 2, 3, 4, 5], isError: (x) => true, defaultValue: 42),
      (x) => x.isEven, [], [2, 4], [1, 3, 5]);

  check(
      create(["a", 1, "b", 2, "c", 3, "d", 4, "e", 5, "f"],
          isError: (x) => x is int, defaultValue: 42),
      (x) => (x is int && x.isEven), // test function
      ["a", "b", "c", "d", "e", "f"], // expected data
      [2, 4], // intercepted errors
      [1, 3, 5] // passed through errors
      );
}