cpp-lazy-stream/test/stream_test.cxx

//
//  stream_td.hpp
//  stream
//
//  Created by Sam Jaffe on 1/28/17.
//

#include "xcode_gtest_helper.h"

#include <map>
#include <string>
#include <vector>

#include "stream/streams.hpp"

using ::testing::ElementsAre;
using ::testing::ElementsAreArray;
using ::testing::Eq;

namespace views = stream::views;
namespace ranges = stream::ranges;

TEST(StreamTest, CanBuildFromSingleElement) {
  int value = 11;
  auto even = [](int i) { return i % 2 == 0; };
  auto s = views::single(value) | views::filter(even);

  EXPECT_THAT(ranges::size(s), 0);
}

TEST(StreamTest, CanBuildFromIterators) {
  std::vector<int> input{1, 2, 3, 4, 5};
  std::vector<int> expected{5, 7};
  auto fmap = [](int i) { return 2 * i + 1; };
  auto out = ranges::subrange(input.begin() + 1, input.begin() + 3) |
             views::transform(fmap) | ranges::to_vector();

  EXPECT_THAT(out, Eq(expected));
}

TEST(StreamTest, CanDereferenceElements) {
  int val = 5;
  std::vector<int *> input{&val};
  auto data = input | views::deref() | ranges::to_vector();

  EXPECT_THAT(data.front(), Eq(val));
}

TEST(StreamTest, CanForEachConsume) {
  int hits = 0;
  std::vector<int> input{1, 2, 3, 4, 5};
  ranges::for_each(views::all(input), [&hits](int) { ++hits; });

  EXPECT_THAT(hits, Eq(5));
}

//
// TEST(StreamTest, CastStreamToParentType) {
//  struct base {
//    char cat[4] = "cat";
//  };
//  struct test : base {
//    test(int v) : val(v) {}
//    int val;
//  };
//  std::vector<test> input{{1}, {3}, {2}};
//
//  auto addressof_void = [](auto const & p) { return (void *)&p; };
//
//  auto strm = stream::of(input).cast<base>();
//  auto first = stream::of(input).map(addressof_void).collect();
//  auto second = strm.map(addressof_void).collect();
//
//  EXPECT_THAT(first, second);
//}