cpp-useful-iterators/test/recursive_iterator_vector_test.cxx

#include "iterator/recursive_iterator.h"

#include <vector>

#include <iterator/forwards.h>

#include "ranges.h"
#include "xcode_gtest_helper.h"

using iterator::bounded;
using iterator::RecursiveIterator;

using testing::ElementsAreArray;
using testing::IsEmpty;

TEST(RecursiveIterator_VecVec, PreIncrementAdvancesIterator) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec);
  EXPECT_THAT(*rit, 1);
  EXPECT_THAT(*++rit, 2);
  EXPECT_THAT(*rit, 2);
}

TEST(RecursiveIterator_VecVec, PostIncrementReturnsCopyOfPrev) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec);
  EXPECT_THAT(*rit, 1);
  EXPECT_THAT(*rit++, 1);
  EXPECT_THAT(*rit, 2);
}

TEST(RecursiveIterator_VecVec, IterDistanceIsSumOfInnerContainerSizes) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec);

  EXPECT_THAT(ranges::distance(rit, iterator::sentinel), 5);
}

TEST(RecursiveIterator_VecVec, FlattensVectorDataLikeJoinIterator) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};

  std::vector<int> const expected{1, 2, 3, 4, 5};
  EXPECT_THAT(vec | views::recursive | ranges::to<std::vector>(),
              ElementsAreArray(expected));
}

TEST(RecursiveIterator_VecVec, CanMutatePointedToData) {
  std::vector<std::vector<std::vector<int>>> vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec);
  *rit = 6;
  EXPECT_THAT(vec[0][0][0], 6);
}

TEST(RecursiveIterator_Vec_Bounded, PreIncrementAdvancesIterator) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec, bounded<2>{});
  EXPECT_THAT(*rit, vec[0][0]);
  EXPECT_THAT(*++rit, vec[1][0]);
  EXPECT_THAT(*rit, vec[1][0]);
}

TEST(RecursiveIterator_Vec_Bounded, PostIncrementReturnsCopyOfPrev) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec, bounded<2>{});
  EXPECT_THAT(*rit, vec[0][0]);
  EXPECT_THAT(*rit++, vec[0][0]);
  EXPECT_THAT(*rit, vec[1][0]);
}

TEST(RecursiveIterator_Vec_Bounded, IterDistanceSumOnNLayersSize) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec, bounded<2>{});

  EXPECT_THAT(ranges::distance(rit, iterator::sentinel), 3);
}

TEST(RecursiveIterator_Vec_Bounded, ElementsAreUnwrappedAsATuple) {
  std::vector<std::vector<std::vector<int>>> const vec{{{1, 2}}, {{3}, {4, 5}}};

  std::vector<std::vector<int>> const expected{{1, 2}, {3}, {4, 5}};
  EXPECT_THAT(vec | views::recursive_n<2> | ranges::to<std::vector>(),
              ElementsAreArray(expected));
}

TEST(RecursiveIterator_Vec_Bounded, CanMutatePointedToData) {
  std::vector<std::vector<std::vector<int>>> vec{{{1, 2}}, {{3}, {4, 5}}};
  auto rit = RecursiveIterator(vec, bounded<2>{});
  rit->clear();
  EXPECT_THAT(vec[0][0], IsEmpty());
}