1 files changed, 206 insertions, 0 deletions
diff --git a/xpcom/tests/gtest/TestTArray.cpp b/xpcom/tests/gtest/TestTArray.cpp
new file mode 100644
index 000000000..10e33664f
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+++ b/xpcom/tests/gtest/TestTArray.cpp
@@ -0,0 +1,206 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "nsTArray.h"
+#include "gtest/gtest.h"
+
+using namespace mozilla;
+
+namespace TestTArray {
+
+struct Copyable
+{
+  Copyable()
+    : mDestructionCounter(nullptr)
+  {
+  }
+
+  ~Copyable()
+  {
+    if (mDestructionCounter) {
+      (*mDestructionCounter)++;
+    }
+  }
+
+  Copyable(const Copyable&) = default;
+  Copyable& operator=(const Copyable&) = default;
+
+  uint32_t* mDestructionCounter;
+};
+
+struct Movable
+{
+  Movable()
+    : mDestructionCounter(nullptr)
+  {
+  }
+
+  ~Movable()
+  {
+    if (mDestructionCounter) {
+      (*mDestructionCounter)++;
+    }
+  }
+
+  Movable(Movable&& aOther)
+    : mDestructionCounter(aOther.mDestructionCounter)
+  {
+    aOther.mDestructionCounter = nullptr;
+  }
+
+  uint32_t* mDestructionCounter;
+};
+
+} // namespace TestTArray
+
+template<>
+struct nsTArray_CopyChooser<TestTArray::Copyable>
+{
+  typedef nsTArray_CopyWithConstructors<TestTArray::Copyable> Type;
+};
+
+template<>
+struct nsTArray_CopyChooser<TestTArray::Movable>
+{
+  typedef nsTArray_CopyWithConstructors<TestTArray::Movable> Type;
+};
+
+namespace TestTArray {
+
+const nsTArray<int>& DummyArray()
+{
+  static nsTArray<int> sArray;
+  if (sArray.IsEmpty()) {
+    const int data[] = {4, 1, 2, 8};
+    sArray.AppendElements(data, ArrayLength(data));
+  }
+  return sArray;
+}
+
+// This returns an invalid nsTArray with a huge length in order to test that
+// fallible operations actually fail.
+#ifdef DEBUG
+const nsTArray<int>& FakeHugeArray()
+{
+  static nsTArray<int> sArray;
+  if (sArray.IsEmpty()) {
+    sArray.AppendElement();
+    ((nsTArrayHeader*)sArray.DebugGetHeader())->mLength = UINT32_MAX;
+  }
+  return sArray;
+}
+#endif
+
+TEST(TArray, AppendElementsRvalue)
+{
+  nsTArray<int> array;
+
+  nsTArray<int> temp(DummyArray());
+  array.AppendElements(Move(temp));
+  ASSERT_EQ(DummyArray(), array);
+  ASSERT_TRUE(temp.IsEmpty());
+
+  temp = DummyArray();
+  array.AppendElements(Move(temp));
+  nsTArray<int> expected;
+  expected.AppendElements(DummyArray());
+  expected.AppendElements(DummyArray());
+  ASSERT_EQ(expected, array);
+  ASSERT_TRUE(temp.IsEmpty());
+}
+
+TEST(TArray, Assign)
+{
+  nsTArray<int> array;
+  array.Assign(DummyArray());
+  ASSERT_EQ(DummyArray(), array);
+
+  ASSERT_TRUE(array.Assign(DummyArray(), fallible));
+  ASSERT_EQ(DummyArray(), array);
+
+#ifdef DEBUG
+  ASSERT_FALSE(array.Assign(FakeHugeArray(), fallible));
+#endif
+
+  nsTArray<int> array2;
+  array2.Assign(Move(array));
+  ASSERT_TRUE(array.IsEmpty());
+  ASSERT_EQ(DummyArray(), array2);
+}
+
+TEST(TArray, AssignmentOperatorSelfAssignment)
+{
+  nsTArray<int> array;
+  array = DummyArray();
+
+  array = array;
+  ASSERT_EQ(DummyArray(), array);
+  array = Move(array);
+  ASSERT_EQ(DummyArray(), array);
+}
+
+TEST(TArray, CopyOverlappingForwards)
+{
+  nsTArray<Movable> array;
+  const size_t rangeLength = 8;
+  const size_t initialLength = 2 * rangeLength;
+  array.AppendElements(initialLength);
+
+  uint32_t destructionCounters[initialLength];
+  for (uint32_t i = 0; i < initialLength; ++i) {
+    destructionCounters[i] = 0;
+  }
+  for (uint32_t i = 0; i < initialLength; ++i) {
+    array[i].mDestructionCounter = &destructionCounters[i];
+  }
+
+  const size_t removedLength = rangeLength / 2;
+  array.RemoveElementsAt(0, removedLength);
+
+  for (uint32_t i = 0; i < removedLength; ++i) {
+    ASSERT_EQ(destructionCounters[i], 1u);
+  }
+  for (uint32_t i = removedLength; i < initialLength; ++i) {
+    ASSERT_EQ(destructionCounters[i], 0u);
+  }
+}
+
+// The code to copy overlapping regions had a bug in that it wouldn't correctly
+// destroy all over the source elements being copied.
+TEST(TArray, CopyOverlappingBackwards)
+{
+  nsTArray<Copyable> array;
+  const size_t rangeLength = 8;
+  const size_t initialLength = 2 * rangeLength;
+  array.SetCapacity(3 * rangeLength);
+  array.AppendElements(initialLength);
+  // To tickle the bug, we need to copy a source region:
+  //
+  //   ..XXXXX..
+  //
+  // such that it overlaps the destination region:
+  //
+  //   ....XXXXX
+  //
+  // so we are forced to copy back-to-front to ensure correct behavior.
+  // The easiest way to do that is to call InsertElementsAt, which will force
+  // the desired kind of shift.
+  uint32_t destructionCounters[initialLength];
+  for (uint32_t i = 0; i < initialLength; ++i) {
+    destructionCounters[i] = 0;
+  }
+  for (uint32_t i = 0; i < initialLength; ++i) {
+    array[i].mDestructionCounter = &destructionCounters[i];
+  }
+
+  array.InsertElementsAt(0, rangeLength);
+
+  for (uint32_t i = 0; i < initialLength; ++i) {
+    ASSERT_EQ(destructionCounters[i], 1u);
+  }
+}
+
+} // namespace TestTArray