unittest: refactor ahead of matcher changes

test/test_utils.dart

+// Copyright (c) 2012, 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 unittest.test_utils;
+
+import 'dart:collection';
+
+import 'package:unittest/unittest.dart';
+
+void shouldFail(value, Matcher matcher, expected) {
+  var failed = false;
+  try {
+    expect(value, matcher);
+  } on TestFailure catch (err) {
+    failed = true;
+
+    var _errorString = err.message;
+
+    if (expected is String) {
+      expect(_errorString, equalsIgnoringWhitespace(expected));
+    } else {
+      expect(_errorString.replaceAll('\n', ''), expected);
+    }
+  }
+
+  expect(failed, isTrue, reason: 'Expected to fail.');
+}
+
+void shouldPass(value, Matcher matcher) {
+  expect(value, matcher);
+}
+
+class Widget {
+  int price;
+}
+
+class HasPrice extends CustomMatcher {
+  HasPrice(matcher) : super("Widget with a price that is", "price", matcher);
+  featureValueOf(actual) => actual.price;
+}
+
+class SimpleIterable extends IterableBase<int> {
+  final int count;
+
+  SimpleIterable(this.count);
+
+  bool contains(int val) => count < val ? false : true;
+
+  bool any(bool f(element)) {
+    for (var i = 0; i <= count; i++) {
+      if (f(i)) return true;
+    }
+    return false;
+  }
+
+  String toString() => "<[$count]>";
+
+  Iterator get iterator {
+    return new _SimpleIterator(count);
+  }
+}
+
+class _SimpleIterator implements Iterator<int> {
+  int _count;
+  int _current;
+
+  _SimpleIterator(this._count);
+
+  bool moveNext() {
+    if (_count > 0) {
+      _current = _count;
+      _count--;
+      return true;
+    }
+    _current = null;
+    return false;
+  }
+
+  int get current => _current;
+}