cpp-useful-iterators/test/unkeyed_iterator_test.cxx

#include "iterator/unkeyed_iterator.h"

#include <map>
#include <vector>

#include "xcode_gtest_helper.h"

#include "iterator/end_aware_iterator.h"

using iterator::end_aware_iterator;
using iterator::unkeyed_iterator;

using testing::Ne;

TEST(UnkeyedIteratorTest, IteratorOnlyReturnsValues) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  std::vector<int> const expected{2, 3};
  std::vector<int> const result{unkeyed_iterator{map.begin()},
                                unkeyed_iterator{map.end()}};
  EXPECT_THAT(result, expected);
}

TEST(UnkeyedIteratorTest, CanModifyIteratedCollectionValues) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  unkeyed_iterator uit{map.begin()};
  *uit = 4;
  EXPECT_THAT(map[1], 4);
}

TEST(UnkeyedIteratorTest, PreIncrementAdvancesIterator) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  unkeyed_iterator it(map.begin());
  EXPECT_THAT(*it, 2);
  EXPECT_THAT(*++it, 3);
  EXPECT_THAT(*it, 3);
}

TEST(UnkeyedIteratorTest, PostIncrementReturnsCopyOfPrev) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  unkeyed_iterator it(map.begin());
  EXPECT_THAT(*it, 2);
  EXPECT_THAT(*it++, 2);
  EXPECT_THAT(*it, 3);
}

TEST(UnkeyedIteratorTest, PreDecrementAdvancesIterator) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  unkeyed_iterator it(++map.begin());
  EXPECT_THAT(*it, 3);
  EXPECT_THAT(*--it, 2);
  EXPECT_THAT(*it, 2);
}

TEST(UnkeyedIteratorTest, PostDecrementReturnsCopyOfPrev) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  unkeyed_iterator it(++map.begin());
  EXPECT_THAT(*it, 3);
  EXPECT_THAT(*it--, 3);
  EXPECT_THAT(*it, 2);
}

TEST(UnkeyedIteratorTest, EqualityIsPassthrough) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  EXPECT_THAT(++unkeyed_iterator(map.begin()), unkeyed_iterator(++map.begin()));
  EXPECT_THAT(unkeyed_iterator(map.begin()),
              Ne(unkeyed_iterator(++map.begin())));
}

TEST(UnkeyedIteratorTest, PropagatesAtEnd) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  unkeyed_iterator end(end_aware_iterator(map.end(), map.end()));
  EXPECT_EQ(end, iterator::sentinel);
}

TEST(UnkeyedIteratorTest, CanPointToObject) {
  std::map<int, int> map{{1, 2}, {2, 3}};
  EXPECT_THAT(unkeyed_iterator(map.begin()).operator->(),
              &(map.begin()->second));
}