test/test_list.cpp

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 */

#include "cx/linked_list.h"
#include "cx/utils.h"
#include "util_allocator.h"

#include <gtest/gtest.h>
#include <array>
#include <vector>
#include <unordered_set>
#include <algorithm>

static int cmp_int_impl(
        int const *l,
        int const *r
) {
    int left = *l, right = *r;
    return left == right ? 0 : (left < right ? -1 : 1);
}

#define cmp_int ((CxListComparator) cmp_int_impl)

struct node {
    node *next = nullptr;
    node *prev = nullptr;
    int data = 0;
};

const ptrdiff_t loc_prev = offsetof(struct node, prev);
const ptrdiff_t loc_next = offsetof(struct node, next);
const ptrdiff_t loc_data = offsetof(struct node, data);

struct node_test_data {
    node *begin;

    explicit node_test_data(node *begin) : begin(begin) {}
    node_test_data(node_test_data&) = delete;
    node_test_data(node_test_data&&) = default;

    ~node_test_data() {
        auto n = begin;
        while (n != nullptr) {
            auto next = n->next;
            delete n;
            n = next;
        }
    }
};

static node_test_data create_nodes_test_data(size_t len) {
    if (len == 0) return node_test_data{nullptr};
    auto begin = new node;
    auto prev = begin;
    for (size_t i = 1; i < len; i++) {
        auto n = new node;
        cx_linked_list_link(prev, n, loc_prev, loc_next);
        prev = n;
    }
    return node_test_data{begin};
}

template<typename InputIter>
static node_test_data create_nodes_test_data(InputIter begin, InputIter end) {
    if (begin == end) return node_test_data{nullptr};
    node *first = new node;
    first->data = *begin;
    node *prev = first;
    begin++;
    for (; begin != end; begin++) {
        auto n = new node;
        n->data = *begin;
        cx_linked_list_link(prev, n, loc_prev, loc_next);
        prev = n;
    }
    return node_test_data{first};
}

static node_test_data create_nodes_test_data(std::initializer_list<int> data) {
    return create_nodes_test_data(data.begin(), data.end());
}

template<size_t N>
struct int_test_data {
    std::array<int, N> data;

    int_test_data() {
        cx_for_n (i, N) data[i] = ::rand(); // NOLINT(cert-msc50-cpp)
    }
};

TEST(LinkedList_LowLevel, link_unlink) {
    node a, b, c;

    cx_linked_list_link(&a, &b, loc_prev, loc_next);
    EXPECT_EQ(a.prev, nullptr);
    EXPECT_EQ(a.next, &b);
    EXPECT_EQ(b.prev, &a);
    EXPECT_EQ(b.next, nullptr);

    cx_linked_list_unlink(&a, &b, loc_prev, loc_next);
    EXPECT_EQ(a.prev, nullptr);
    EXPECT_EQ(a.next, nullptr);
    EXPECT_EQ(b.prev, nullptr);
    EXPECT_EQ(b.next, nullptr);

    cx_linked_list_link(&b, &c, loc_prev, loc_next);
    cx_linked_list_link(&a, &b, loc_prev, loc_next);
    cx_linked_list_unlink(&b, &c, loc_prev, loc_next);
    EXPECT_EQ(a.prev, nullptr);
    EXPECT_EQ(a.next, &b);
    EXPECT_EQ(b.prev, &a);
    EXPECT_EQ(b.next, nullptr);
    EXPECT_EQ(c.prev, nullptr);
    EXPECT_EQ(c.next, nullptr);
}

TEST(LinkedList_LowLevel, cx_linked_list_at) {
    node a, b, c, d;
    cx_linked_list_link(&a, &b, loc_prev, loc_next);
    cx_linked_list_link(&b, &c, loc_prev, loc_next);
    cx_linked_list_link(&c, &d, loc_prev, loc_next);

    EXPECT_EQ(cx_linked_list_at(&a, 0, loc_next, 0), &a);
    EXPECT_EQ(cx_linked_list_at(&a, 0, loc_next, 1), &b);
    EXPECT_EQ(cx_linked_list_at(&a, 0, loc_next, 2), &c);
    EXPECT_EQ(cx_linked_list_at(&a, 0, loc_next, 3), &d);
    EXPECT_EQ(cx_linked_list_at(&a, 0, loc_next, 4), nullptr);

    EXPECT_EQ(cx_linked_list_at(&b, 1, loc_prev, 0), &a);
    EXPECT_EQ(cx_linked_list_at(&b, 1, loc_next, 1), &b);
    EXPECT_EQ(cx_linked_list_at(&b, 1, loc_next, 2), &c);
    EXPECT_EQ(cx_linked_list_at(&b, 1, loc_next, 3), &d);
    EXPECT_EQ(cx_linked_list_at(&b, 1, loc_next, 4), nullptr);

    EXPECT_EQ(cx_linked_list_at(&d, 3, loc_prev, 0), &a);
    EXPECT_EQ(cx_linked_list_at(&d, 3, loc_prev, 1), &b);
}

TEST(LinkedList_LowLevel, cx_linked_list_find) {
    auto testdata = create_nodes_test_data({2, 4, 6, 8});
    auto list = testdata.begin;
    int s;

    s = 2;
    EXPECT_EQ(cx_linked_list_find(list, loc_next, loc_data, false, cmp_int, &s), 0);
    s = 4;
    EXPECT_EQ(cx_linked_list_find(list, loc_next, loc_data, false, cmp_int, &s), 1);
    s = 6;
    EXPECT_EQ(cx_linked_list_find(list, loc_next, loc_data, false, cmp_int, &s), 2);
    s = 8;
    EXPECT_EQ(cx_linked_list_find(list, loc_next, loc_data, false, cmp_int, &s), 3);
    s = 10;
    EXPECT_EQ(cx_linked_list_find(list, loc_next, loc_data, false, cmp_int, &s), 4);
    s = -2;
    EXPECT_EQ(cx_linked_list_find(list, loc_next, loc_data, false, cmp_int, &s), 4);
}

TEST(LinkedList_LowLevel, cx_linked_list_compare) {
    auto ta = create_nodes_test_data({2, 4, 6, 8});
    auto tb = create_nodes_test_data({2, 4, 6});
    auto tc = create_nodes_test_data({2, 4, 6, 9});
    auto la = ta.begin, lb = tb.begin, lc = tc.begin;

    EXPECT_GT(cx_linked_list_compare(la, lb, loc_next, loc_data, false, cmp_int), 0);
    EXPECT_LT(cx_linked_list_compare(lb, la, loc_next, loc_data, false, cmp_int), 0);
    EXPECT_GT(cx_linked_list_compare(lc, la, loc_next, loc_data, false, cmp_int), 0);
    EXPECT_LT(cx_linked_list_compare(la, lc, loc_next, loc_data, false, cmp_int), 0);
    EXPECT_EQ(cx_linked_list_compare(la, la, loc_next, loc_data, false, cmp_int), 0);
}

TEST(LinkedList_LowLevel, cx_linked_list_add) {
    // test with begin, end / prev, next
    {
        node nodes[4];
        void *begin = nullptr, *end = nullptr;

        cx_linked_list_add(&begin, &end, loc_prev, loc_next, &nodes[0]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[0]);
        EXPECT_EQ(nodes[0].prev, nullptr);
        EXPECT_EQ(nodes[0].next, nullptr);

        cx_linked_list_add(&begin, &end, loc_prev, loc_next, &nodes[1]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[1]);
        EXPECT_EQ(nodes[0].next, &nodes[1]);
        EXPECT_EQ(nodes[1].prev, &nodes[0]);
    }

    // test with begin only / prev, next
    {
        node nodes[4];
        void *begin = nullptr;

        cx_linked_list_add(&begin, nullptr, loc_prev, loc_next, &nodes[0]);
        EXPECT_EQ(begin, &nodes[0]);
        cx_linked_list_add(&begin, nullptr, loc_prev, loc_next, &nodes[1]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(nodes[0].next, &nodes[1]);
        EXPECT_EQ(nodes[1].prev, &nodes[0]);

        cx_linked_list_add(&begin, nullptr, loc_prev, loc_next, &nodes[2]);
        EXPECT_EQ(nodes[1].next, &nodes[2]);
        EXPECT_EQ(nodes[2].prev, &nodes[1]);
    }

    // test with end only / prev, next
    {
        node nodes[4];
        void *end = nullptr;

        cx_linked_list_add(nullptr, &end, loc_prev, loc_next, &nodes[0]);
        EXPECT_EQ(end, &nodes[0]);
        cx_linked_list_add(nullptr, &end, loc_prev, loc_next, &nodes[1]);
        EXPECT_EQ(end, &nodes[1]);
        EXPECT_EQ(nodes[0].next, &nodes[1]);
        EXPECT_EQ(nodes[1].prev, &nodes[0]);

        cx_linked_list_add(nullptr, &end, loc_prev, loc_next, &nodes[2]);
        EXPECT_EQ(end, &nodes[2]);
        EXPECT_EQ(nodes[1].next, &nodes[2]);
        EXPECT_EQ(nodes[2].prev, &nodes[1]);
    }

    // test with begin, end / next
    {
        node nodes[4];
        void *begin = nullptr, *end = nullptr;

        cx_linked_list_add(&begin, &end, -1, loc_next, &nodes[0]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[0]);
        cx_linked_list_add(&begin, &end, -1, loc_next, &nodes[1]);
        EXPECT_EQ(end, &nodes[1]);
        EXPECT_EQ(nodes[0].next, &nodes[1]);
        EXPECT_EQ(nodes[1].prev, nullptr);
    }
}

TEST(LinkedList_LowLevel, cx_linked_list_prepend) {
    // test with begin, end / prev, next
    {
        node nodes[4];
        void *begin = nullptr, *end = nullptr;

        cx_linked_list_prepend(&begin, &end, loc_prev, loc_next, &nodes[0]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[0]);
        EXPECT_EQ(nodes[0].prev, nullptr);
        EXPECT_EQ(nodes[0].next, nullptr);

        cx_linked_list_prepend(&begin, &end, loc_prev, loc_next, &nodes[1]);
        EXPECT_EQ(begin, &nodes[1]);
        EXPECT_EQ(end, &nodes[0]);
        EXPECT_EQ(nodes[1].next, &nodes[0]);
        EXPECT_EQ(nodes[0].prev, &nodes[1]);
    }

    // test with begin only / prev, next
    {
        node nodes[4];
        void *begin = nullptr;

        cx_linked_list_prepend(&begin, nullptr, loc_prev, loc_next, &nodes[0]);
        EXPECT_EQ(begin, &nodes[0]);
        cx_linked_list_prepend(&begin, nullptr, loc_prev, loc_next, &nodes[1]);
        EXPECT_EQ(begin, &nodes[1]);
        EXPECT_EQ(nodes[1].next, &nodes[0]);
        EXPECT_EQ(nodes[0].prev, &nodes[1]);

        cx_linked_list_prepend(&begin, nullptr, loc_prev, loc_next, &nodes[2]);
        EXPECT_EQ(begin, &nodes[2]);
        EXPECT_EQ(nodes[2].next, &nodes[1]);
        EXPECT_EQ(nodes[1].prev, &nodes[2]);
    }

    // test with end only / prev, next
    {
        node nodes[4];
        void *end = nullptr;

        cx_linked_list_prepend(nullptr, &end, loc_prev, loc_next, &nodes[0]);
        EXPECT_EQ(end, &nodes[0]);
        cx_linked_list_prepend(nullptr, &end, loc_prev, loc_next, &nodes[1]);
        EXPECT_EQ(end, &nodes[0]);
        EXPECT_EQ(nodes[1].next, &nodes[0]);
        EXPECT_EQ(nodes[0].prev, &nodes[1]);

        cx_linked_list_prepend(nullptr, &end, loc_prev, loc_next, &nodes[2]);
        EXPECT_EQ(end, &nodes[0]);
        EXPECT_EQ(nodes[2].next, &nodes[1]);
        EXPECT_EQ(nodes[1].prev, &nodes[2]);
    }

    // test with begin, end / next
    {
        node nodes[4];
        void *begin = nullptr, *end = nullptr;

        cx_linked_list_prepend(&begin, &end, -1, loc_next, &nodes[0]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[0]);
        cx_linked_list_prepend(&begin, &end, -1, loc_next, &nodes[1]);
        cx_linked_list_prepend(&begin, &end, -1, loc_next, &nodes[2]);
        EXPECT_EQ(begin, &nodes[2]);
        EXPECT_EQ(end, &nodes[0]);
        EXPECT_EQ(nodes[1].next, &nodes[0]);
        EXPECT_EQ(nodes[2].next, &nodes[1]);
        EXPECT_EQ(nodes[1].prev, nullptr);
        EXPECT_EQ(nodes[0].prev, nullptr);
    }
}

TEST(LinkedList_LowLevel, cx_linked_list_insert) {
    // insert mid list
    {
        node nodes[4];
        void *begin = &nodes[0], *end = &nodes[2];

        cx_linked_list_link(&nodes[0], &nodes[1], loc_prev, loc_next);
        cx_linked_list_link(&nodes[1], &nodes[2], loc_prev, loc_next);

        cx_linked_list_insert(&begin, &end, loc_prev, loc_next, &nodes[1], &nodes[3]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[2]);
        EXPECT_EQ(nodes[1].next, &nodes[3]);
        EXPECT_EQ(nodes[2].prev, &nodes[3]);
        EXPECT_EQ(nodes[3].prev, &nodes[1]);
        EXPECT_EQ(nodes[3].next, &nodes[2]);
    }

    // insert end
    {
        node nodes[4];
        void *begin = &nodes[0], *end = &nodes[2];

        cx_linked_list_link(&nodes[0], &nodes[1], loc_prev, loc_next);
        cx_linked_list_link(&nodes[1], &nodes[2], loc_prev, loc_next);

        cx_linked_list_insert(&begin, &end, loc_prev, loc_next, &nodes[2], &nodes[3]);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[3]);
        EXPECT_EQ(nodes[2].next, &nodes[3]);
        EXPECT_EQ(nodes[3].prev, &nodes[2]);
        EXPECT_EQ(nodes[3].next, nullptr);
    }

    // insert begin
    {
        node nodes[4];
        void *begin = &nodes[0], *end = &nodes[2];

        cx_linked_list_link(&nodes[0], &nodes[1], loc_prev, loc_next);
        cx_linked_list_link(&nodes[1], &nodes[2], loc_prev, loc_next);

        cx_linked_list_insert(&begin, &end, loc_prev, loc_next, nullptr, &nodes[3]);
        EXPECT_EQ(begin, &nodes[3]);
        EXPECT_EQ(end, &nodes[2]);
        EXPECT_EQ(nodes[0].prev, &nodes[3]);
        EXPECT_EQ(nodes[3].prev, nullptr);
        EXPECT_EQ(nodes[3].next, &nodes[0]);
    }
}

TEST(LinkedList_LowLevel, cx_linked_list_insert_chain) {
    // insert mid list
    {
        node nodes[5];
        void *begin = &nodes[0], *end = &nodes[2];

        cx_linked_list_link(&nodes[0], &nodes[1], loc_prev, loc_next);
        cx_linked_list_link(&nodes[1], &nodes[2], loc_prev, loc_next);
        cx_linked_list_link(&nodes[3], &nodes[4], loc_prev, loc_next);

        cx_linked_list_insert_chain(&begin, &end, loc_prev, loc_next, &nodes[1], &nodes[3], nullptr);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[2]);
        EXPECT_EQ(nodes[1].next, &nodes[3]);
        EXPECT_EQ(nodes[2].prev, &nodes[4]);
        EXPECT_EQ(nodes[3].prev, &nodes[1]);
        EXPECT_EQ(nodes[4].next, &nodes[2]);
    }

    // insert end
    {
        node nodes[5];
        void *begin = &nodes[0], *end = &nodes[2];

        cx_linked_list_link(&nodes[0], &nodes[1], loc_prev, loc_next);
        cx_linked_list_link(&nodes[1], &nodes[2], loc_prev, loc_next);
        cx_linked_list_link(&nodes[3], &nodes[4], loc_prev, loc_next);

        cx_linked_list_insert_chain(&begin, &end, loc_prev, loc_next, &nodes[2], &nodes[3], nullptr);
        EXPECT_EQ(begin, &nodes[0]);
        EXPECT_EQ(end, &nodes[4]);
        EXPECT_EQ(nodes[2].next, &nodes[3]);
        EXPECT_EQ(nodes[3].prev, &nodes[2]);
        EXPECT_EQ(nodes[4].next, nullptr);
    }

    // insert begin
    {
        node nodes[5];
        void *begin = &nodes[0], *end = &nodes[2];

        cx_linked_list_link(&nodes[0], &nodes[1], loc_prev, loc_next);
        cx_linked_list_link(&nodes[1], &nodes[2], loc_prev, loc_next);
        cx_linked_list_link(&nodes[3], &nodes[4], loc_prev, loc_next);

        cx_linked_list_insert_chain(&begin, &end, loc_prev, loc_next, nullptr, &nodes[3], nullptr);
        EXPECT_EQ(begin, &nodes[3]);
        EXPECT_EQ(end, &nodes[2]);
        EXPECT_EQ(nodes[0].prev, &nodes[4]);
        EXPECT_EQ(nodes[3].prev, nullptr);
        EXPECT_EQ(nodes[4].next, &nodes[0]);
    }
}

TEST(LinkedList_LowLevel, cx_linked_list_first) {
    auto testdata = create_nodes_test_data(3);
    auto begin = testdata.begin;
    EXPECT_EQ(cx_linked_list_first(begin, loc_prev), begin);
    EXPECT_EQ(cx_linked_list_first(begin->next, loc_prev), begin);
    EXPECT_EQ(cx_linked_list_first(begin->next->next, loc_prev), begin);
}

TEST(LinkedList_LowLevel, cx_linked_list_last) {
    auto testdata = create_nodes_test_data(3);
    auto begin = testdata.begin;
    auto end = begin->next->next;
    EXPECT_EQ(cx_linked_list_last(begin, loc_next), end);
    EXPECT_EQ(cx_linked_list_last(begin->next, loc_next), end);
    EXPECT_EQ(cx_linked_list_last(begin->next->next, loc_next), end);
}

TEST(LinkedList_LowLevel, cx_linked_list_prev) {
    auto testdata = create_nodes_test_data(3);
    auto begin = testdata.begin;
    EXPECT_EQ(cx_linked_list_prev(begin, loc_next, begin), nullptr);
    EXPECT_EQ(cx_linked_list_prev(begin, loc_next, begin->next), begin);
    EXPECT_EQ(cx_linked_list_prev(begin, loc_next, begin->next->next), begin->next);
}

TEST(LinkedList_LowLevel, cx_linked_list_remove) {
    auto testdata = create_nodes_test_data({2, 4, 6});
    auto begin = reinterpret_cast<void *>(testdata.begin);
    auto first = testdata.begin;
    auto second = first->next;
    auto third = second->next;
    auto end = reinterpret_cast<void *>(third);

    cx_linked_list_remove(&begin, &end, loc_prev, loc_next, second);
    EXPECT_EQ(begin, first);
    EXPECT_EQ(end, third);
    EXPECT_EQ(first->prev, nullptr);
    EXPECT_EQ(first->next, third);
    EXPECT_EQ(third->prev, first);
    EXPECT_EQ(third->next, nullptr);

    cx_linked_list_remove(&begin, &end, loc_prev, loc_next, third);
    EXPECT_EQ(begin, first);
    EXPECT_EQ(end, first);
    EXPECT_EQ(first->prev, nullptr);
    EXPECT_EQ(first->next, nullptr);

    cx_linked_list_remove(&begin, &end, loc_prev, loc_next, first);
    EXPECT_EQ(begin, nullptr);
    EXPECT_EQ(end, nullptr);
}

TEST(LinkedList_LowLevel, cx_linked_list_size) {
    EXPECT_EQ(cx_linked_list_size(nullptr, loc_next), 0);

    {
        auto testdata = create_nodes_test_data(5);
        EXPECT_EQ(cx_linked_list_size(testdata.begin, loc_next), 5);
    }

    {
        auto testdata = create_nodes_test_data(13);
        EXPECT_EQ(cx_linked_list_size(testdata.begin, loc_next), 13);
    }
}

TEST(LinkedList_LowLevel, cx_linked_list_sort) {
    int_test_data<1000> testdata;
    std::array<int, 1000> sorted{};
    std::partial_sort_copy(testdata.data.begin(), testdata.data.end(), sorted.begin(), sorted.end());

    auto scrambled = create_nodes_test_data(testdata.data.begin(), testdata.data.end());
    void *begin = scrambled.begin;
    void *end = cx_linked_list_last(begin, loc_next);

    cx_linked_list_sort(&begin, &end, loc_prev, loc_next, loc_data,
                        false, cmp_int);

    node *check = reinterpret_cast<node *>(begin);
    node *check_last = nullptr;
    cx_for_n (i, sorted.size()) {
        EXPECT_EQ(check->data, sorted[i]);
        EXPECT_EQ(check->prev, check_last);
        if (i < sorted.size() - 1) {
            ASSERT_NE(check->next, nullptr);
        }
        check_last = check;
        check = check->next;
    }
    EXPECT_EQ(check, nullptr);
    EXPECT_EQ(end, check_last);
}

TEST(LinkedList_LowLevel, cx_linked_list_reverse) {
    auto testdata = create_nodes_test_data({2, 4, 6, 8});
    auto expected = create_nodes_test_data({8, 6, 4, 2});

    auto begin = reinterpret_cast<void *>(testdata.begin);
    auto end = cx_linked_list_last(begin, loc_next);
    auto orig_begin = begin, orig_end = end;

    cx_linked_list_reverse(&begin, &end, loc_prev, loc_next);
    EXPECT_EQ(end, orig_begin);
    EXPECT_EQ(begin, orig_end);
    EXPECT_EQ(cx_linked_list_compare(begin, expected.begin, loc_next, loc_data, 0, cmp_int), 0);
}

class HighLevelTest : public ::testing::Test {
    mutable std::unordered_set<CxList *> lists;
protected:
    CxTestingAllocator testingAllocator;

    void TearDown() override {
        for (auto &&l: lists) cxListDestroy(l);
        EXPECT_TRUE(testingAllocator.verify());
    }

    static constexpr size_t testdata_len = 250;
    int_test_data<testdata_len> testdata;

    auto autofree(CxList *list) const -> CxList * {
        lists.insert(list);
        return list;
    }

    auto linkedListFromTestData() const -> CxList * {
        return autofree(
                cxLinkedListFromArray(
                        &testingAllocator,
                        cmp_int,
                        sizeof(int),
                        testdata_len,
                        testdata.data.data()
                )
        );
    }

    auto pointerLinkedListFromTestData() const -> CxList * {
        auto list = autofree(cxPointerLinkedListCreate(&testingAllocator, cmp_int));
        cx_for_n(i, testdata_len) cxListAdd(list, &testdata.data[i]);
        return list;
    }

    void verifyCreate(CxList *list) const {
        EXPECT_EQ(list->size, 0);
        EXPECT_EQ(list->capacity, (size_t) -1);
        EXPECT_EQ(list->allocator, &testingAllocator);
        EXPECT_EQ(list->cmpfunc, cmp_int);
    }

    void verifyAdd(CxList *list, bool write_through) {
        auto len = testdata_len;
        cx_for_n (i, len) EXPECT_EQ(cxListAdd(list, &testdata.data[i]), 0);
        EXPECT_EQ(list->size, len);
        EXPECT_GE(list->capacity, list->size);
        cx_for_n (i, len) EXPECT_EQ(*(int *) cxListAt(list, i), testdata.data[i]);
        cx_for_n (i, len) ++testdata.data[i];
        if (write_through) {
            cx_for_n (i, len) EXPECT_EQ(*(int *) cxListAt(list, i), testdata.data[i]);
        } else {
            cx_for_n (i, len) EXPECT_EQ(*(int *) cxListAt(list, i), testdata.data[i] - 1);
        }
    }

    static void verifyInsert(CxList *list) {
        int a = 5, b = 47, c = 13, d = 42;

        EXPECT_NE(cxListInsert(list, 1, &a), 0);
        EXPECT_EQ(list->size, 0);
        EXPECT_EQ(cxListInsert(list, 0, &a), 0);
        EXPECT_EQ(list->size, 1);
        EXPECT_EQ(cxListInsert(list, 0, &b), 0);
        EXPECT_EQ(list->size, 2);
        EXPECT_EQ(cxListInsert(list, 1, &c), 0);
        EXPECT_EQ(list->size, 3);
        EXPECT_EQ(cxListInsert(list, 3, &d), 0);

        EXPECT_EQ(list->size, 4);
        EXPECT_GE(list->capacity, list->size);

        EXPECT_EQ(*(int *) cxListAt(list, 0), 47);
        EXPECT_EQ(*(int *) cxListAt(list, 1), 13);
        EXPECT_EQ(*(int *) cxListAt(list, 2), 5);
        EXPECT_EQ(*(int *) cxListAt(list, 3), 42);
    }

    void verifyRemove(CxList *list) const {
        EXPECT_EQ(cxListRemove(list, 2), 0);
        EXPECT_EQ(cxListRemove(list, 4), 0);
        EXPECT_EQ(list->size, testdata_len - 2);
        EXPECT_GE(list->capacity, list->size);
        EXPECT_EQ(*(int *) cxListAt(list, 0), testdata.data[0]);
        EXPECT_EQ(*(int *) cxListAt(list, 1), testdata.data[1]);
        EXPECT_EQ(*(int *) cxListAt(list, 2), testdata.data[3]);
        EXPECT_EQ(*(int *) cxListAt(list, 3), testdata.data[4]);
        EXPECT_EQ(*(int *) cxListAt(list, 4), testdata.data[6]);

        EXPECT_EQ(cxListRemove(list, 0), 0);
        EXPECT_EQ(list->size, testdata_len - 3);
        EXPECT_GE(list->capacity, list->size);
        EXPECT_EQ(*(int *) cxListAt(list, 0), testdata.data[1]);
        EXPECT_EQ(*(int *) cxListAt(list, 1), testdata.data[3]);

        EXPECT_NE(cxListRemove(list, testdata_len), 0);
    }

    void verifyAt(CxList *list) const {
        auto len = testdata_len;
        EXPECT_EQ(list->size, len);
        cx_for_n (i, list->size) EXPECT_EQ(*(int *) cxListAt(list, i), testdata.data[i]);
        EXPECT_EQ(cxListAt(list, list->size), nullptr);
    }

    void verifyFind(CxList *list) const {
        cx_for_n (attempt, 25) {
            size_t exp = rand() % testdata_len; // NOLINT(cert-msc50-cpp)
            int val = testdata.data[exp];
            // randomly picked number could occur earlier in list - find first position
            cx_for_n (i, exp) {
                if (testdata.data[i] == val) {
                    exp = i;
                    break;
                }
            }
            EXPECT_EQ(cxListFind(list, &val), exp);
        }
    }

    void verifySort(CxList *list) const {
        std::array<int, testdata_len> expected{};
        std::partial_sort_copy(testdata.data.begin(), testdata.data.end(), expected.begin(), expected.end());
        cxListSort(list);
        cx_for_n (i, testdata_len) ASSERT_EQ(*(int *) cxListAt(list, i), expected[i]);
    }

    void verifyIterator(CxList *list) const {
        int i = 0;
        CxIterator iter = cxListBegin(list);
        cx_foreach(int*, x, iter) {
            ASSERT_EQ(iter.index, (size_t) (i + 1) / 2);
            ASSERT_EQ(*x, testdata.data[i]);
            if (i % 2 == 1) iter.remove = true;
            i++;
        }
        auto len = testdata_len;
        EXPECT_EQ(i, len);
        ASSERT_EQ(list->size, len / 2);
        cx_for_n(j, len / 2) ASSERT_EQ(*(int *) cxListAt(list, j), testdata.data[j * 2]);
    }

    static void verifyInsertViaIterator(CxList *list) {
        int newdata[] = {10, 20, 30, 40, 50};

        CxIterator iter = cxListIterator(list, 2);
        EXPECT_TRUE(cxIteratorValid(&iter));
        EXPECT_EQ(iter.index, 2);
        EXPECT_EQ(*(int *) cxIteratorCurrent(&iter), 2);
        cxListInsertAfter(&iter, &newdata[0]);
        EXPECT_TRUE(cxIteratorValid(&iter));
        EXPECT_EQ(iter.index, 2);
        EXPECT_EQ(*(int *) cxIteratorCurrent(&iter), 2);
        cxListInsertBefore(&iter, &newdata[1]);
        EXPECT_TRUE(cxIteratorValid(&iter));
        EXPECT_EQ(iter.index, 3);
        EXPECT_EQ(*(int *) cxIteratorCurrent(&iter), 2);

        iter = cxListBegin(list);
        cxListInsertBefore(&iter, &newdata[2]);
        EXPECT_TRUE(cxIteratorValid(&iter));
        EXPECT_EQ(iter.index, 1);
        EXPECT_EQ(*(int *) cxIteratorCurrent(&iter), 0);
        iter = cxListIterator(list, list->size);
        cxListInsertBefore(&iter, &newdata[3]);
        EXPECT_FALSE(cxIteratorValid(&iter));
        EXPECT_EQ(iter.index, 9);
        iter = cxListIterator(list, list->size);
        cxListInsertAfter(&iter, &newdata[4]);
        EXPECT_FALSE(cxIteratorValid(&iter));
        EXPECT_EQ(iter.index, 10);

        int expdata[] = {30, 0, 1, 20, 2, 10, 3, 4, 40, 50};
        cx_for_n (j, 10) EXPECT_EQ(*(int *) cxListAt(list, j), expdata[j]);
    }
};

class LinkedList : public HighLevelTest {
};

class PointerLinkedList : public HighLevelTest {
};

TEST_F(LinkedList, cxLinkedListCreate) {
    CxList *list = autofree(cxLinkedListCreate(&testingAllocator, cmp_int, sizeof(int)));
    EXPECT_EQ(list->itemsize, sizeof(int));
    verifyCreate(list);
}

TEST_F(PointerLinkedList, cxPointerLinkedListCreate) {
    CxList *list = autofree(cxPointerLinkedListCreate(&testingAllocator, cmp_int));
    EXPECT_EQ(list->itemsize, sizeof(void *));
    verifyCreate(list);
}

TEST_F(LinkedList, cxLinkedListFromArray) {
    CxList *expected = autofree(cxLinkedListCreate(&testingAllocator, cmp_int, sizeof(int)));
    cx_for_n (i, testdata_len) cxListAdd(expected, &testdata.data[i]);
    CxList *list = autofree(cxLinkedListFromArray(&testingAllocator, cmp_int, sizeof(int),
                                                  testdata_len, testdata.data.data()));
    EXPECT_EQ(cxListCompare(list, expected), 0);
}

TEST_F(LinkedList, cxListAdd) {
    CxList *list = autofree(cxLinkedListCreate(&testingAllocator, cmp_int, sizeof(int)));
    verifyAdd(list, false);
}

TEST_F(PointerLinkedList, cxListAdd) {
    CxList *list = autofree(cxPointerLinkedListCreate(&testingAllocator, cmp_int));
    verifyAdd(list, true);
}

TEST_F(LinkedList, cxListInsert) {
    verifyInsert(autofree(cxLinkedListCreate(&testingAllocator, cmp_int, sizeof(int))));
}

TEST_F(PointerLinkedList, cxListInsert) {
    verifyInsert(autofree(cxPointerLinkedListCreate(&testingAllocator, cmp_int)));
}

TEST_F(LinkedList, cxListRemove) {
    verifyRemove(linkedListFromTestData());
}

TEST_F(PointerLinkedList, cxListRemove) {
    verifyRemove(pointerLinkedListFromTestData());
}

TEST_F(LinkedList, cxListAt) {
    verifyAt(linkedListFromTestData());
}

TEST_F(PointerLinkedList, cxListAt) {
    verifyAt(pointerLinkedListFromTestData());
}

TEST_F(LinkedList, cxListFind) {
    verifyFind(linkedListFromTestData());
}

TEST_F(PointerLinkedList, cxListFind) {
    verifyFind(pointerLinkedListFromTestData());
}

TEST_F(LinkedList, cxListSort) {
    verifySort(linkedListFromTestData());
}

TEST_F(PointerLinkedList, cxListSort) {
    verifySort(pointerLinkedListFromTestData());
}

TEST_F(LinkedList, Iterator) {
    verifyIterator(linkedListFromTestData());
}

TEST_F(PointerLinkedList, Iterator) {
    verifyIterator(pointerLinkedListFromTestData());
}

TEST_F(LinkedList, InsertViaIterator) {
    int fivenums[] = {0, 1, 2, 3, 4, 5};
    CxList *list = autofree(cxLinkedListFromArray(&testingAllocator, cmp_int, sizeof(int), 5, fivenums));
    verifyInsertViaIterator(list);
}

TEST_F(PointerLinkedList, InsertViaIterator) {
    int fivenums[] = {0, 1, 2, 3, 4, 5};
    CxList *list = autofree(cxPointerLinkedListCreate(&testingAllocator, cmp_int));
    cx_for_n (i, 5) cxListAdd(list, &fivenums[i]);
    verifyInsertViaIterator(list);
}