Implements matchers WhenSorted() and WhenSortedBy(); pulls in gtest r595.

include/gmock/gmock-matchers.h

@@ -1970,6 +1970,85 @@ class ContainerEqMatcher {
   GTEST_DISALLOW_ASSIGN_(ContainerEqMatcher);
 };
 
+// A comparator functor that uses the < operator to compare two values.
+struct LessComparator {
+  template <typename T, typename U>
+  bool operator()(const T& lhs, const U& rhs) const { return lhs < rhs; }
+};
+
+// Implements WhenSortedBy(comparator, container_matcher).
+template <typename Comparator, typename ContainerMatcher>
+class WhenSortedByMatcher {
+ public:
+  WhenSortedByMatcher(const Comparator& comparator,
+                      const ContainerMatcher& matcher)
+      : comparator_(comparator), matcher_(matcher) {}
+
+  template <typename LhsContainer>
+  operator Matcher<LhsContainer>() const {
+    return MakeMatcher(new Impl<LhsContainer>(comparator_, matcher_));
+  }
+
+  template <typename LhsContainer>
+  class Impl : public MatcherInterface<LhsContainer> {
+   public:
+    typedef internal::StlContainerView<
+         GTEST_REMOVE_REFERENCE_AND_CONST_(LhsContainer)> LhsView;
+    typedef typename LhsView::type LhsStlContainer;
+    typedef typename LhsView::const_reference LhsStlContainerReference;
+    typedef typename LhsStlContainer::value_type LhsValue;
+
+    Impl(const Comparator& comparator, const ContainerMatcher& matcher)
+        : comparator_(comparator), matcher_(matcher) {}
+
+    virtual void DescribeTo(::std::ostream* os) const {
+      *os << "(when sorted) ";
+      matcher_.DescribeTo(os);
+    }
+
+    virtual void DescribeNegationTo(::std::ostream* os) const {
+      *os << "(when sorted) ";
+      matcher_.DescribeNegationTo(os);
+    }
+
+    virtual bool MatchAndExplain(LhsContainer lhs,
+                                 MatchResultListener* listener) const {
+      LhsStlContainerReference lhs_stl_container = LhsView::ConstReference(lhs);
+      std::vector<LhsValue> sorted_container(lhs_stl_container.begin(),
+                                             lhs_stl_container.end());
+      std::sort(sorted_container.begin(), sorted_container.end(), comparator_);
+
+      if (!listener->IsInterested()) {
+        // If the listener is not interested, we do not need to
+        // construct the inner explanation.
+        return matcher_.Matches(sorted_container);
+      }
+
+      *listener << "which is ";
+      UniversalPrint(sorted_container, listener->stream());
+      *listener << " when sorted";
+
+      StringMatchResultListener inner_listener;
+      const bool match = matcher_.MatchAndExplain(sorted_container,
+                                                  &inner_listener);
+      PrintIfNotEmpty(inner_listener.str(), listener->stream());
+      return match;
+    }
+
+   private:
+    const Comparator comparator_;
+    const Matcher<const std::vector<LhsValue>&> matcher_;
+
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(Impl);
+  };
+
+ private:
+  const Comparator comparator_;
+  const ContainerMatcher matcher_;
+
+  GTEST_DISALLOW_ASSIGN_(WhenSortedByMatcher);
+};
+
 // Implements Pointwise(tuple_matcher, rhs_container).  tuple_matcher
 // must be able to be safely cast to Matcher<tuple<const T1&, const
 // T2&> >, where T1 and T2 are the types of elements in the LHS
@@ -2930,6 +3009,26 @@ inline PolymorphicMatcher<internal::ContainerEqMatcher<  // NOLINT
       internal::ContainerEqMatcher<RawContainer>(rhs));
 }
 
+// Returns a matcher that matches a container that, when sorted using
+// the given comparator, matches container_matcher.
+template <typename Comparator, typename ContainerMatcher>
+inline internal::WhenSortedByMatcher<Comparator, ContainerMatcher>
+WhenSortedBy(const Comparator& comparator,
+             const ContainerMatcher& container_matcher) {
+  return internal::WhenSortedByMatcher<Comparator, ContainerMatcher>(
+      comparator, container_matcher);
+}
+
+// Returns a matcher that matches a container that, when sorted using
+// the < operator, matches container_matcher.
+template <typename ContainerMatcher>
+inline internal::WhenSortedByMatcher<internal::LessComparator, ContainerMatcher>
+WhenSorted(const ContainerMatcher& container_matcher) {
+  return
+      internal::WhenSortedByMatcher<internal::LessComparator, ContainerMatcher>(
+          internal::LessComparator(), container_matcher);
+}
+
 // Matches an STL-style container or a native array that contains the
 // same number of elements as in rhs, where its i-th element and rhs's
 // i-th element (as a pair) satisfy the given pair matcher, for all i.

test/gmock-matchers_test.cc

@@ -57,6 +57,8 @@ GTEST_API_ string JoinAsTuple(const Strings& fields);
 
 namespace gmock_matchers_test {
 
+using std::greater;
+using std::less;
 using std::list;
 using std::make_pair;
 using std::map;
@@ -118,6 +120,8 @@ using testing::StrNe;
 using testing::Truly;
 using testing::TypedEq;
 using testing::Value;
+using testing::WhenSorted;
+using testing::WhenSortedBy;
 using testing::_;
 using testing::internal::DummyMatchResultListener;
 using testing::internal::ExplainMatchFailureTupleTo;
@@ -3725,6 +3729,83 @@ TEST(ContainerEqExtraTest, CopiesNativeArrayParameter) {
   EXPECT_THAT(a1, m);
 }
 
+TEST(WhenSortedByTest, WorksForEmptyContainer) {
+  const vector<int> numbers;
+  EXPECT_THAT(numbers, WhenSortedBy(less<int>(), ElementsAre()));
+  EXPECT_THAT(numbers, Not(WhenSortedBy(less<int>(), ElementsAre(1))));
+}
+
+TEST(WhenSortedByTest, WorksForNonEmptyContainer) {
+  vector<unsigned> numbers;
+  numbers.push_back(3);
+  numbers.push_back(1);
+  numbers.push_back(2);
+  numbers.push_back(2);
+  EXPECT_THAT(numbers, WhenSortedBy(greater<unsigned>(),
+                                    ElementsAre(3, 2, 2, 1)));
+  EXPECT_THAT(numbers, Not(WhenSortedBy(greater<unsigned>(),
+                                        ElementsAre(1, 2, 2, 3))));
+}
+
+TEST(WhenSortedByTest, WorksForNonVectorContainer) {
+  list<string> words;
+  words.push_back("say");
+  words.push_back("hello");
+  words.push_back("world");
+  EXPECT_THAT(words, WhenSortedBy(less<string>(),
+                                  ElementsAre("hello", "say", "world")));
+  EXPECT_THAT(words, Not(WhenSortedBy(less<string>(),
+                                      ElementsAre("say", "hello", "world"))));
+}
+
+TEST(WhenSortedByTest, WorksForNativeArray) {
+  const int numbers[] = { 1, 3, 2, 4 };
+  const int sorted_numbers[] = { 1, 2, 3, 4 };
+  EXPECT_THAT(numbers, WhenSortedBy(less<int>(), ElementsAre(1, 2, 3, 4)));
+  EXPECT_THAT(numbers, WhenSortedBy(less<int>(),
+                                    ElementsAreArray(sorted_numbers)));
+  EXPECT_THAT(numbers, Not(WhenSortedBy(less<int>(), ElementsAre(1, 3, 2, 4))));
+}
+
+TEST(WhenSortedByTest, CanDescribeSelf) {
+  const Matcher<vector<int> > m = WhenSortedBy(less<int>(), ElementsAre(1, 2));
+  EXPECT_EQ("(when sorted) has 2 elements where\n"
+            "element #0 is equal to 1,\n"
+            "element #1 is equal to 2",
+            Describe(m));
+  EXPECT_EQ("(when sorted) doesn't have 2 elements, or\n"
+            "element #0 isn't equal to 1, or\n"
+            "element #1 isn't equal to 2",
+            DescribeNegation(m));
+}
+
+TEST(WhenSortedByTest, ExplainsMatchResult) {
+  const int a[] = { 2, 1 };
+  EXPECT_EQ("which is { 1, 2 } when sorted, whose element #0 doesn't match",
+            Explain(WhenSortedBy(less<int>(), ElementsAre(2, 3)), a));
+  EXPECT_EQ("which is { 1, 2 } when sorted",
+            Explain(WhenSortedBy(less<int>(), ElementsAre(1, 2)), a));
+}
+
+// WhenSorted() is a simple wrapper on WhenSortedBy().  Hence we don't
+// need to test it as exhaustively as we test the latter.
+
+TEST(WhenSortedTest, WorksForEmptyContainer) {
+  const vector<int> numbers;
+  EXPECT_THAT(numbers, WhenSorted(ElementsAre()));
+  EXPECT_THAT(numbers, Not(WhenSorted(ElementsAre(1))));
+}
+
+TEST(WhenSortedTest, WorksForNonEmptyContainer) {
+  list<string> words;
+  words.push_back("3");
+  words.push_back("1");
+  words.push_back("2");
+  words.push_back("2");
+  EXPECT_THAT(words, WhenSorted(ElementsAre("1", "2", "2", "3")));
+  EXPECT_THAT(words, Not(WhenSorted(ElementsAre("3", "1", "2", "2"))));
+}
+
 // Tests IsReadableTypeName().
 
 TEST(IsReadableTypeNameTest, ReturnsTrueForShortNames) {