blob: 7241171181675cc7e836708bfc8510cd928a1775 [file] [log] [blame]
// 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 scheduled_future_matchers;
import 'dart:async';
import 'package:stack_trace/stack_trace.dart';
import '../scheduled_test.dart';
/// Matches a [Future] that completes successfully with a value. Note that this
/// creates an asynchronous expectation. The call to `expect()` that includes
/// this will return immediately and execution will continue. Later, when the
/// future completes, the actual expectation will run.
///
/// To test that a Future completes with an exception, you can use [throws] and
/// [throwsA].
///
/// This differs from the `completes` matcher in `unittest` in that it pipes any
/// errors in the Future to [currentSchedule], rather than reporting them in the
/// [expect]'s error message.
final Matcher completes = const _ScheduledCompletes(null, null);
/// Matches a [Future] that completes succesfully with a value that matches
/// [matcher]. Note that this creates an asynchronous expectation. The call to
/// `expect()` that includes this will return immediately and execution will
/// continue. Later, when the future completes, the actual expectation will run.
///
/// To test that a Future completes with an exception, you can use [throws] and
/// [throwsA].
///
/// [description] is an optional tag that can be used to identify the completion
/// matcher in error messages.
///
/// This differs from the `completion` matcher in `unittest` in that it pipes
/// any errors in the Future to [currentSchedule], rather than reporting them in
/// the [expect]'s error message.
Matcher completion(matcher, [String description]) =>
new _ScheduledCompletes(wrapMatcher(matcher), description);
class _ScheduledCompletes extends Matcher {
final Matcher _matcher;
final String _description;
const _ScheduledCompletes(this._matcher, this._description);
bool matches(item, Map matchState) {
if (item is! Future) return false;
// TODO(nweiz): parse the stack, figure out on what line these were called,
// and include that in their descriptions
var description = _description;
if (description == null) {
if (_matcher == null) {
description = 'expect(..., completes)';
} else {
var matcherDescription = new StringDescription();
_matcher.describe(matcherDescription);
description = 'expect(..., completion($matcherDescription))';
}
}
var outerTrace = new Trace.current();
currentSchedule.wrapFuture(item.then((value) {
if (_matcher == null) return;
// TODO(floitsch): we cannot switch traces anymore.
// If expect throws we might want to be able to switch to the outer trace
// instead.
expect(value, _matcher);
}), description);
return true;
}
Description describe(Description description) {
if (_matcher == null) {
description.add('completes successfully');
} else {
description.add('completes to a value that ').addDescriptionOf(_matcher);
}
return description;
}
}