[NTP Snippets] Refactor home-grown container API

components/ntp_snippets/inner_iterator_unittest.cc

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <memory>
-#include <vector>
-
-#include "components/ntp_snippets/inner_iterator.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace {
-
-int ii[] = {0, 1, 2, 3, 4};
-
-class InnerIteratorTest : public testing::Test {
- protected:
-  using ListType = std::vector<int*>;
-
-  void SetUp() override {
-    ints_.push_back(&ii[0]);
-    ints_.push_back(&ii[1]);
-    ints_.push_back(&ii[2]);
-    ints_.push_back(&ii[3]);
-    ints_.push_back(&ii[4]);
-  }
-
-  ListType ints_;
-};
-
-TEST_F(InnerIteratorTest, Create) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.begin());
-  EXPECT_EQ(0, *x);
-}
-TEST_F(InnerIteratorTest, PreIncrement) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.begin());
-  EXPECT_EQ(1, *(++x));
-  EXPECT_EQ(1, *x);
-}
-TEST_F(InnerIteratorTest, PostIncrement) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.begin());
-  EXPECT_EQ(0, *(x++));
-  EXPECT_EQ(1, *x);
-}
-TEST_F(InnerIteratorTest, Add) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.begin());
-  EXPECT_EQ(2, *(x + 2));
-  EXPECT_EQ(0, *x);
-}
-TEST_F(InnerIteratorTest, Sub) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.end());
-  EXPECT_EQ(2, *(x - 3));
-  EXPECT_EQ(4, *(--x));
-}
-TEST_F(InnerIteratorTest, PreDecrement) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.end());
-  EXPECT_EQ(4, *(--x));
-  EXPECT_EQ(4, *x);
-}
-TEST_F(InnerIteratorTest, PostDecrement) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.end());
-  EXPECT_EQ(4, *(--x));
-  EXPECT_EQ(4, *(x--));
-  EXPECT_EQ(3, *x);
-}
-TEST_F(InnerIteratorTest, Equality) {
-  ntp_snippets::InnerIterator<ListType::iterator, int> x(ints_.begin());
-  ntp_snippets::InnerIterator<ListType::iterator, int> y(ints_.end());
-  x += 2;
-  y -= 3;
-  EXPECT_EQ(x, y);
-}
-
-}  // namespace