gecko-dev/xpcom/tests/gtest/TestObserverArray.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
// vim:cindent:ts=4:et:sw=4:
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsTObserverArray.h"
#include "gtest/gtest.h"

using namespace mozilla;

typedef nsTObserverArray<int> IntArray;

#define DO_TEST(_type, _exp, _code)                                   \
  do {                                                                \
    ++testNum;                                                        \
    count = 0;                                                        \
    IntArray::_type iter(arr);                                        \
    while (iter.HasMore() && count != ArrayLength(_exp)) {            \
      _code                                                           \
      int next = iter.GetNext();                                      \
      int expected = _exp[count++];                                   \
      ASSERT_EQ(next, expected) << "During test " << testNum << " at position " << count - 1;  \
    }                                                                 \
    ASSERT_FALSE(iter.HasMore()) << "During test " << testNum << ", iterator ran over"; \
    ASSERT_EQ(count, ArrayLength(_exp)) << "During test " << testNum << ", iterator finished too early"; \
  } while (0)

TEST(ObserverArray, Tests)
{
  IntArray arr;
  arr.AppendElement(3);
  arr.AppendElement(4);

  size_t count;
  int testNum = 0;

  // Basic sanity
  static int test1Expected[] = { 3, 4 };
  DO_TEST(ForwardIterator, test1Expected, { /* nothing */ });

  // Appends
  static int test2Expected[] = { 3, 4, 2 };
  DO_TEST(ForwardIterator, test2Expected,
          if (count == 1) arr.AppendElement(2);
          );
  DO_TEST(ForwardIterator, test2Expected, { /* nothing */ });

  DO_TEST(EndLimitedIterator, test2Expected,
          if (count == 1) arr.AppendElement(5);
          );

  static int test5Expected[] = { 3, 4, 2, 5 };
  DO_TEST(ForwardIterator, test5Expected, { /* nothing */ });

  // Removals
  DO_TEST(ForwardIterator, test5Expected,
          if (count == 1) arr.RemoveElementAt(0);
          );

  static int test7Expected[] = { 4, 2, 5 };
  DO_TEST(ForwardIterator, test7Expected, { /* nothing */ });

  static int test8Expected[] = { 4, 5 };
  DO_TEST(ForwardIterator, test8Expected,
          if (count == 1) arr.RemoveElementAt(1);
          );
  DO_TEST(ForwardIterator, test8Expected, { /* nothing */ });

  arr.AppendElement(2);
  arr.AppendElementUnlessExists(6);
  static int test10Expected[] = { 4, 5, 2, 6 };
  DO_TEST(ForwardIterator, test10Expected, { /* nothing */ });

  arr.AppendElementUnlessExists(5);
  DO_TEST(ForwardIterator, test10Expected, { /* nothing */ });

  static int test12Expected[] = { 4, 5, 6 };
  DO_TEST(ForwardIterator, test12Expected,
          if (count == 1) arr.RemoveElementAt(2);
          );
  DO_TEST(ForwardIterator, test12Expected, { /* nothing */ });

  // Removals + Appends
  static int test14Expected[] = { 4, 6, 7 };
  DO_TEST(ForwardIterator, test14Expected,
          if (count == 1) {
            arr.RemoveElementAt(1);
            arr.AppendElement(7);
          }
          );
  DO_TEST(ForwardIterator, test14Expected, { /* nothing */ });

  arr.AppendElement(2);
  static int test16Expected[] = { 4, 6, 7, 2 };
  DO_TEST(ForwardIterator, test16Expected, { /* nothing */ });

  static int test17Expected[] = { 4, 7, 2 };
  DO_TEST(EndLimitedIterator, test17Expected,
          if (count == 1) {
            arr.RemoveElementAt(1);
            arr.AppendElement(8);
          }
          );

  static int test18Expected[] = { 4, 7, 2, 8 };
  DO_TEST(ForwardIterator, test18Expected, { /* nothing */ });

  // Prepends
  arr.PrependElementUnlessExists(3);
  static int test19Expected[] = { 3, 4, 7, 2, 8 };
  DO_TEST(ForwardIterator, test19Expected, { /* nothing */ });

  arr.PrependElementUnlessExists(7);
  DO_TEST(ForwardIterator, test19Expected, { /* nothing */ });

  DO_TEST(ForwardIterator, test19Expected,
          if (count == 1) {
            arr.PrependElementUnlessExists(9);
          }
          );

  static int test22Expected[] = { 9, 3, 4, 7, 2, 8 };
  DO_TEST(ForwardIterator, test22Expected, { });

  // BackwardIterator
  static int test23Expected[] = { 8, 2, 7, 4, 3, 9 };
  DO_TEST(BackwardIterator, test23Expected, );

  // Removals
  static int test24Expected[] = { 8, 2, 7, 4, 9 };
  DO_TEST(BackwardIterator, test24Expected,
          if (count == 1) arr.RemoveElementAt(1);
          );

  // Appends
  DO_TEST(BackwardIterator, test24Expected,
          if (count == 1) arr.AppendElement(1);
          );

  static int test26Expected[] = { 1, 8, 2, 7, 4, 9 };
  DO_TEST(BackwardIterator, test26Expected, );

  // Prepends
  static int test27Expected[] = { 1, 8, 2, 7, 4, 9, 3 };
  DO_TEST(BackwardIterator, test27Expected,
          if (count == 1) arr.PrependElementUnlessExists(3);
          );

  // Removal using Iterator
  DO_TEST(BackwardIterator, test27Expected,
          // when this code runs, |GetNext()| has only been called once, so
          // this actually removes the very first element
          if (count == 1) iter.Remove();
          );

  static int test28Expected[] = { 8, 2, 7, 4, 9, 3 };
  DO_TEST(BackwardIterator, test28Expected, );

  /**
   * Note: _code is executed before the call to GetNext(), it can therefore not
   * test the case of prepending when the BackwardIterator already returned the
   * first element.
   * In that case BackwardIterator does not traverse the newly prepended Element
   */

}