cpp-useful-iterators/test/join_iterator_test.cxx

#include "iterator/join_iterator.hpp"

#include <vector>

#include <gmock/gmock.h>

using join_iterator = iterator::joining_iterator<std::vector<std::vector<int>>::iterator>;

TEST(JoinIteratorTest, FirstDereferencedElemIsTheFirstInTheChain) {
  std::vector<std::vector<int>> mv{{1,2,3},{4,5,6}};
  EXPECT_THAT(*join_iterator(make_end_aware_iterator(mv)), mv[0][0]);
}

TEST(JoinIteratorTest, EmptyConstructorEqualsEnd) {
  std::vector<std::vector<int>> mv{{1,2,3},{4,5,6}};
  join_iterator it({ mv.end(), mv.end() }, { mv.back().end(), mv.back().end() } );
  EXPECT_THAT(it, join_iterator());
}

TEST(JoinIteratorTest, MovesFromListToListWhenReachingEnd) {
  std::vector<std::vector<int>> mv{{1,2,3},{4,5,6}};
  join_iterator it(make_end_aware_iterator(mv), { mv[0].end(), mv[0].end() });
  EXPECT_THAT(*++it, mv[1][0]);
}

TEST(JoinIteratorTest, IncrementEndIsNoOp) {
  std::vector<std::vector<int>> mv{{1,2,3},{4,5,6}};
  join_iterator it( { mv.end(), mv.end() }, { mv.back().end(), mv.back().end() });
  join_iterator const cp = it;
  ++it;
  EXPECT_THAT(it, cp);
}