New expectation functions plus convert old tests to use these.

lib/unittest/collection_matchers.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.
+
+/**
+ * Returns a matcher which matches [Collection]s in which all elements
+ * match the given [matcher].
+ */
+Matcher everyElement(matcher) => new _EveryElement(wrapMatcher(matcher));
+
+class _EveryElement extends _CollectionMatcher {
+  Matcher _matcher;
+
+  _EveryElement(Matcher this._matcher);
+
+  bool matches(item) {
+    return item.every((e) => _matcher.matches(e));
+  }
+
+  Description describe(Description description) =>
+      description.add('every element ').addDescriptionOf(_matcher);
+}
+
+/**
+ * Returns a matcher which matches [Collection]s in which at least one
+ * element matches the given [matcher].
+ */
+Matcher someElement(matcher) => new _SomeElement(wrapMatcher(matcher));
+
+class _SomeElement extends _CollectionMatcher {
+  Matcher _matcher;
+
+  _SomeElement(this._matcher);
+
+  bool matches(item) {
+    return item.some( (e) => _matcher.matches(e) );
+  }
+
+  Description describe(Description description) =>
+      description.add('some element ').addDescriptionOf(_matcher);
+}
+
+/**
+ * Returns a matcher which matches [Iterable]s that have the same
+ * length and the same elements as [expected], and in the same order.
+ */
+Matcher orderedEquals(Iterable expected) => new _OrderedEquals(expected);
+
+class _OrderedEquals extends BaseMatcher {
+  Iterable _expected;
+
+  _OrderedEquals(this._expected);
+
+  String _test(item) {
+    return _compareIterables(_expected, item,
+      (expected, actual, location) => expected == actual? null : location);
+  }
+
+  bool matches(item) => (_test(item) == null);
+
+  Description describe(Description description) =>
+      description.add('equals ').addDescriptionOf(_expected).add(' ordered');
+
+  Description describeMismatch(item, Description mismatchDescription) =>
+      mismatchDescription.add(_test(item));
+}
+
+/**
+ * Returns a matcher which matches [Iterable]s that have the same
+ * length and the same elements as [expected], but not necessarily in
+ * the same order. Note that this is O(n^2) so should only be used on
+ * small objects.
+ */
+Matcher unorderedEquals(Iterable expected) =>
+    new _UnorderedEquals(expected);
+
+class _UnorderedEquals extends BaseMatcher {
+  Iterable _expected;
+
+  _UnorderedEquals(Iterable this._expected);
+
+  String _test(item) {
+    if (item is !Iterable) {
+      return 'not iterable';
+    }
+    // Check the lengths are the same.
+    var expectedLength = 0;
+    if (_expected is Collection) {
+      Collection cast = _expected; // "_expected as Collection"
+      expectedLength = cast.length;
+    } else {
+      for (var element in _expected) {
+        ++expectedLength;
+      }
+    }
+    var actualLength = 0;
+    if (item is Collection) {
+      actualLength = item.length;
+    } else {
+      for (var element in item) {
+        ++actualLength;
+      }
+    }
+    if (expectedLength > actualLength) {
+      return 'has too few elements (${actualLength} < ${expectedLength})';
+    } else if (expectedLength < actualLength) {
+      return 'has too many elements (${actualLength} > ${expectedLength})';
+    }
+    List<bool> matched = new List<bool>(actualLength);
+    var expectedPosition = 0;
+    for (var expectedElement in _expected) {
+      var actualPosition = 0;
+      var gotMatch = false;
+      for (var actualElement in item) {
+        if (!matched[actualPosition]) {
+          if (expectedElement == actualElement) {
+            matched[actualPosition] = gotMatch = true;
+            break;
+          }
+        }
+        ++actualPosition;
+      }
+      if (!gotMatch) {
+        return 'has no match for element ${expectedElement} '
+               'at position ${expectedPosition}';
+      }
+      ++expectedPosition;
+    }
+    return null;
+  }
+
+  bool matches(item) => (_test(item) == null);
+
+  Description describe(Description description) =>
+      description.add('equals ').addDescriptionOf(_expected).add(' unordered');
+
+  Description describeMismatch(item, Description mismatchDescription) =>
+      mismatchDescription.add(_test(item));
+}
+
+/**
+ * Collection matchers match against [Collection]s. We add this intermediate
+ * class to give better mismatch error messages than the base Matcher class.
+ */
+
+/*abstract*/ class _CollectionMatcher extends BaseMatcher {
+  const _CollectionMatcher();
+  Description describeMismatch(item, Description mismatchDescription) {
+    if (item is !Collection) {
+      return mismatchDescription.
+          addDescriptionOf(item).
+          add(' not a collection');
+    } else {
+      return super.describeMismatch(item, mismatchDescription);
+    }
+  }
+}